PhD

An increasingly number of patients with symptomatic isolated medial unicompartmental knee osteoarthritis (OA) are too young and too functionally active to be ideal candidates for total knee arthroplasty (TKA). Isolated medial compartment OA occurs in 10% to 29.5% of all cases, whereas the isolated lateral variant is less common, with a reported incidence of 1% to 7%.^1,2 In 1961, Jackson and Waugh³ introduced the high tibial osteotomy (HTO) as a surgical treatment for single-compartment OA. This procedure is designed to increase the life span of articular cartilage by unloading and redistributing the mechanical forces over the nonaffected compartment. Unicompartmental knee arthroplasty (UKA) was introduced in the 1970s as an alternative to TKA or HTO for single-compartment OA.

Since the introduction of these methods, there has been debate about which patients are appropriate candidates for each procedure. Improved surgical techniques and implant designs have led surgeons to reexamine the selection criteria and contraindications for these procedures. Furthermore, given the increasing popularity and use of UKA, the question arises as to whether HTO still has a role in clinical practice in the surgical treatment of medial OA of the knee.

To clarify current ambiguities, we review the modern indications, subjective outcome scores, and survivorship results of UKA and HTO in the treatment of isolated medial compartment degeneration of the knee. In addition, in a thorough review of the literature, we evaluate global trends in the use of both methods.

High Tibial Osteotomy for Medial Compartment OA

Indications

Before the introduction of TKA and UKA for single-compartment OA, surgical management consisted of HTO. When the mechanical axis is slightly overcorrected, the medial compartment is decompressed, ensuring tissue viability and delaying progressive compartment degeneration.

Traditionally, HTO is indicated for young (age <60 years), normal-weight, active patients with radiographic single-compartment OA.⁶ The knee should be stable and have good range of motion (ROM; flexion >120°), and pain should be localized to the tibiofemoral joint line.

Over the past few decades, numerous authors have reported similar inclusion criteria, clarifying their definition. This definition should be further refined in order to optimize survivorship and clinical outcomes.

Confirming age as an inclusion criterion for HTO, Trieb and colleagues⁷ found that the risk of failure was significantly (P = .046) higher for HTO patients older than 65 years than for those younger than 65 years (relative risk, 1.5). This finding agrees with findings of other studies, which suggests that, in particular, young patients benefit from HTO.^8-11

Moreover, there is a clear relation between HTO survival and obesity. In a study of 159 CWHTOs, Akizuki and colleagues¹² reported that preoperative body mass index (BMI) higher than 27.5 kg/m² was a significant risk factor for early failure. Using BMI higher than 30 kg/m² as a threshold, Howells and colleagues⁹ found significantly inferior Knee Society Score (KSS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) results for the obese group 5 years after HTO.

Radiographic evidence of severe preoperative compartment degeneration has been associated with early conversion to TKA. Flecher and colleagues¹¹ and van Raaij and colleagues¹³ both concluded the best long-term survival grades are achieved in HTO patients with mild compartment OA (Ahlbäck^14 grade I). The question then becomes whether these patients should be treated nonoperatively instead.^15,16The literature supports strict adherence to inclusion criteria in the selection of a potential HTO candidate. Age, BMI, and the preoperative state of OA should be taken into account in order to optimize clinical outcome and survivorship results in patients about to undergo HTO.

Outcomes

Multiple authors have described or compared the midterm or long-term results of the various surgical HTO techniques. Howells and colleagues⁹ noted overall survival rates of 87% (5 years after CWHTO) and 79% (10 years after CWHTO). Over the 10-year postoperative period, there was significant deterioration in clinical outcome scores and survivorship. Others authors have had similar findings.^17-19 van Raaij and colleagues¹³ found that the 10-year probability of survival after CWHTO was 75%. In 455 patients who underwent lateral CWHTO, Hui and colleagues⁸ found that 5-year probability of survival was 95%, 10-year probability was 79%, and 15-year probability was 56%. Niinimäki and colleagues¹⁰ used the Finnish Arthroplasty Register to report HTO survivorship at a national level. Using conversion to TKA as a cutoff, they noted 5-year survivorship of 89% and 10-year survivorship of 73%. To our knowledge, 2 groups, both in Japan, have reported substantially higher 15-year survival rates: 90%¹² and 93%.²⁰ The authors acknowledged that their results were significantly better than in other countries and that Japanese lifestyle, culture, and body habitus therefore require further investigation. At this time, it is not possible to compare their results with Western results.

In an attempt to compare the different survival rates of the various HTO techniques, Schallberger and colleagues²¹ conducted a retrospective study of OWHTOs and CWHTOs. At median follow-up of 16.5 years, comparative survival rates showed a trend of deterioration. Although data were limited, there were no significant differences in survival or functional outcome between the 2 techniques. In a recent randomized clinical trial, Duivenvoorden and colleagues⁵ compared these techniques’ midterm results (mean follow-up, 6 years). Clinical outcomes were not significantly different. There were more complications in the OWHTO group and more conversions to TKA in the CWHTO group. Considering these results, the authors suggested OWHTO without autologous bone graft is the best HTO treatment strategy for medial gonarthritis with varus malalignment of <12°.

The HTO results noted in these studies show a similar deteriorating trend; expected 10-year survivorship is 75%. Although modern implants and surgical techniques are being used, evidence supporting use of one surgical HTO method over another is lacking.

UKA for Medial Compartment OA

Indications

Since it was first introduced in the 1970s, use of UKA for single-compartment OA has been a subject of debate. The high failure rates reported at the time raised skepticism about the new treatment.²² Kozinn and Scott²³ defined classic indications and contraindications. Indications included isolated medial or lateral compartment OA or osteonecrosis of the knee, age over 60 years, and weight under 82 kg. In addition, the angular deformity of the affected lower extremity had to be <15° and passively correctable to neutral at time of surgery. Last, the flexion contracture had to be <5°, and ideal ROM was 90°. Contraindications included high activity, age under 60 years, and inflammatory arthritis. Strict adherence led to improved implant survival and lower revision rates. Because of improved surgical techniques, modern implant designs, and accumulating experience with the procedure, the surgical indications for UKA have expanded. Exact thresholds for UKA inclusion, however, remain unclear.

The modern literature is overturning the traditional idea that UKA is not indicated for patients under age 60 years.²³ Using KSS, Thompson and colleagues²⁴ found that younger patients did better than older patients 2 years after UKA using various types of implants. Analyzing survivorship results, Heyse and colleagues²⁵ concluded that UKA can be successful in patients under age 60 years and reported a 15-year survivorship rate of 85.6% and excellent outcome scores. Other authors have had similar findings.^26-28

Evaluating the influence of weight, Thompson and colleagues²⁴ found obese patients did not have a higher revision rate but did have slower progression of improvement 2 years after UKA. Cavaignac and colleagues²⁹ concluded that, at minimum follow-up of 7 years (range, 7-22 years), weight did not influence UKA survivorship. Other authors^30-33 have found no significant influence of BMI on survival.

Reports on preoperative radiographic parameters that can potentially influence UKA results are limited. In 113 medial UKAs studied by Niinimäki and colleagues,³⁴ mild medial compartment degeneration, seen on preoperative radiographs, was associated with significantly higher failure rates. The authors concluded that other treatment options should be favored in the absence of severe isolated compartment OA.

Although the classic indications defined by Kozinn and Scott²³ have yielded good to excellent UKA results, improvements in implants and surgical techniques^35-38 have extended the criteria. The modern literature demonstrates that age and BMI should not be used as criteria for excluding UKA candidates. Radiographically, there should be significant isolated compartment degeneration in order to optimize patient-reported outcome and survivorship.

Outcomes

Improved implant designs and modern minimally invasive techniques have effected a change in outcome results and a renewed interest in implants. Over the past decade, multiple authors have described the various modern UKA implants and their survivorship. Reports published since UKA was introduced in the 1970s show a continual increase in implant survival. Koskinen and colleagues,³⁹ using Finnish Arthroplasty Register data on 1819 UKAs performed between 1985 and 2003, found 10-year survival rates of 81% for Oxford implants (Zimmer Biomet), 79% for Miller-Galante II (Zimmer Biomet), 78% for Duracon (Howmedica), and 53% for PCA unicompartmental knee (Howmedica). Heyse and colleagues²⁵ reported 10- and 15-year survivorship data (93.5% and 86.3%, respectively) for 223 patients under age 60 years at the time of their index surgery (Genesis Unicondylar implant, Smith & Nephew), performed between 1993 and 2005. KSS was good to excellent. Similar numbers in cohorts under age 60 years were reported by Schai and colleagues²⁶ using the PFC system (Johnson & Johnson) and by Price and colleagues²⁷ using the medial Oxford UKA. Both groups reported excellent survivorship rates: 93% at 2- to 6-year follow-up and 91% at 10-year follow-up. The outcome in older patients seems satisfactory as well. In another multicenter report, by Price and colleagues,⁴⁰ medial Oxford UKAs had a 15-year survival rate of 93%. Berger and colleagues⁴¹ reported similar numbers for the Miller-Galante prosthesis. Survival rates were 98% (10 years) and 95.7% (13 years), and 92% of patients had good to excellent Hospital for Special Surgery knee scores.

Although various modern implants have had good to excellent results, the historical question of what type of UKA to use (mobile or fixed-bearing) remains unanswered. To try to address it, Peersman and colleagues⁴² performed a systematic review of 44 papers (9463 knees). The 2 implant types had comparable revision rates. Another recent retrospective study tried to determine what is crucial for implant survival: implant design or surgeon experience.⁴³ The authors concluded that prosthetic component positioning is key. Other authors have reported high-volume centers are crucial for satisfactory UKA results and lower revision rates.^44-46

Results of these studies indicate that, where UKAs are being performed in volume, 10-year survivorship rates higher than 90% and good to excellent outcomes can be expected.

UKA vs HTO

Cohort studies that have directly compared the 2 treatment modalities are scarce, and most have been retrospective. In a prospective study, Stukenborg-Colsman and colleagues⁴⁷ randomized patients with medial compartment OA to undergo either CWHTO (32 patients) with a technique reported by Coventry⁴⁸ or UKA (28 patients) with the unicondylar knee sliding prosthesis, Tübingen pattern (Aesculap), between 1988 and 1991. Patients were assessed 2.5, 4.5, and 7.5 years after surgery. More postoperative complications were noted in the HTO group. At 7- to 10-year follow-up, 71% of the HTO group and 65% of the UKA group had excellent KSS. Mean ROM was 103° after UKA (range, 35°-140°) and 117° after HTO (range, 85°-135°) during the same assessment. Although differences were not significant, Kaplan-Meier survival analysis was 60% for HTO and 77% for UKA at 10 years. Results were not promising for the implants used, compared with other implants, but the authors concluded that, because of improvements in implant designs and image-guided techniques, better long-term success can be expected with UKA than with HTO.

In another prospective study, Börjesson and colleagues⁴⁹ evaluated pain during walking, ROM, British Orthopaedic Association (BOA) scores, and gait variables at 1- and 5-year follow-up. Patients with moderate medial OA (Ahlbäck¹⁴ grade I-III) were randomly selected to undergo CWHTO or UKA (Brigham, DePuy). There were no significant differences in BOA scores, ROM, or pain during walking between the 2 groups at 3 months, 1 year, and 5 years after surgery. Gait analysis showed a significant difference in favor of UKA only at 3 months after surgery. At 1- and 5-year follow-up, no significant differences were noted.

To clarify current ambiguities, Fu and colleagues⁵⁰ performed a systematic review of all (11) comparative studies. These studies had a total of 5840 (5081 UKA, 759 HTO) patients. Although ROM was significantly better for the HTO group than the UKA group, the UKA group had significantly better functional results. Walking after surgery was significantly faster for the UKA group. The authors suggested the difference might be attributed to the different postoperative regimens—HTO patients wore a whole-leg plaster cast for 6 weeks, and UKA patients were allowed immediate postoperative weight-bearing. Regarding rates of survival and complications, pooled data showed no significant differences. Despite these results, the authors acknowledged the limitation of available randomized clinical trials and the multiple techniques and implants used. We share their assertion that larger prospective controlled trials are needed. These are crucial to getting a definitive answer regarding which of the 2 treatment strategies should be used for isolated compartment OA.

Current Trends in Use of UKA and HTO

Evaluation of national registries and recent reports showed a global shift in use of both HTO and UKA. Despite the lack of national HTO registries, a few reports have described use of TKA, UKA, and HTO in Western populations over the past 2 decades. Using 1998-2007 data from the Swedish Knee Arthroplasty Register, W-Dahl and colleagues⁵¹ found a 3-fold increase in UKA use, whereas HTO use was halved over the same period. Niinimäki and colleagues⁵² reported similar findings with the Finnish National Hospital Discharge Register. They noted a steady 6.8% annual decrease in osteotomies, whereas UKA use increased sharply after the Oxford UKA was introduced (Phase 3; Biomet). These findings are consistent with several reports from North America. In their epidemiologic analysis covering the period 1985-1990, Wright and colleagues⁵³ found an 11% to 14% annual decrease in osteotomies among the elderly, compared with an annual decrease of only 3% to 4% among patients younger than 65 years. Nwachukwu and colleagues⁵⁴ recently compared UKA and HTO practice patterns between 2007 and 2011, using data from a large US private payer insurance database. They noted an annual growth rate of 4.7% in UKA use, compared with an annual 3.9% decrease in HTO use. Furthermore, based on their subgroup analysis, they speculated there was a demographic shift toward UKA, as opposed to TKA, particularly in older women. Bolognesi and colleagues⁵⁵ investigated further. Evaluating all Medicare beneficiaries who underwent knee arthroplasty in the United States between 2000 and 2009, they noted a 1.7-fold increase in TKA use and a 6.2-fold increase in UKA use. As there were no substantial changes in patient characteristics over that period, the authors hypothesized that a possible broadening of inclusion criteria may have led to the increased use of UKA.

There is a possible multifactorial explanation for the current global shift in favor of UKA. First, UKA was once a technically demanding procedure, but improved surgical techniques, image guidance, and robot assistance⁵⁶ have made it relatively less difficult. Second, UKA surgery is associated with lower reported perioperative morbidities.⁵⁷ We think these factors have contributed to the global trend of less HTO use and more UKA use in the treatment of unicompartmental OA.

Conclusion

The modern literature suggests the inclusion criteria for HTO have been well investigated and defined; the UKA criteria remain a matter of debate but seem to be expanding. Long-term survival results seem to favor UKA, though patient satisfaction with both procedures is good to excellent. The broadening range of inclusion criteria and consistent reports of durable outcomes, coupled with excellent patient satisfaction, likely explain the shift toward UKA in the treatment of isolated compartment degeneration.

Am J Orthop. 2016;45(6):E355-E361. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

An increasingly number of patients with symptomatic isolated medial unicompartmental knee osteoarthritis (OA) are too young and too functionally active to be ideal candidates for total knee arthroplasty (TKA). Isolated medial compartment OA occurs in 10% to 29.5% of all cases, whereas the isolated lateral variant is less common, with a reported incidence of 1% to 7%.^1,2 In 1961, Jackson and Waugh³ introduced the high tibial osteotomy (HTO) as a surgical treatment for single-compartment OA. This procedure is designed to increase the life span of articular cartilage by unloading and redistributing the mechanical forces over the nonaffected compartment. Unicompartmental knee arthroplasty (UKA) was introduced in the 1970s as an alternative to TKA or HTO for single-compartment OA.

Since the introduction of these methods, there has been debate about which patients are appropriate candidates for each procedure. Improved surgical techniques and implant designs have led surgeons to reexamine the selection criteria and contraindications for these procedures. Furthermore, given the increasing popularity and use of UKA, the question arises as to whether HTO still has a role in clinical practice in the surgical treatment of medial OA of the knee.

To clarify current ambiguities, we review the modern indications, subjective outcome scores, and survivorship results of UKA and HTO in the treatment of isolated medial compartment degeneration of the knee. In addition, in a thorough review of the literature, we evaluate global trends in the use of both methods.

High Tibial Osteotomy for Medial Compartment OA

Indications

Before the introduction of TKA and UKA for single-compartment OA, surgical management consisted of HTO. When the mechanical axis is slightly overcorrected, the medial compartment is decompressed, ensuring tissue viability and delaying progressive compartment degeneration.

Traditionally, HTO is indicated for young (age <60 years), normal-weight, active patients with radiographic single-compartment OA.⁶ The knee should be stable and have good range of motion (ROM; flexion >120°), and pain should be localized to the tibiofemoral joint line.

Over the past few decades, numerous authors have reported similar inclusion criteria, clarifying their definition. This definition should be further refined in order to optimize survivorship and clinical outcomes.

Confirming age as an inclusion criterion for HTO, Trieb and colleagues⁷ found that the risk of failure was significantly (P = .046) higher for HTO patients older than 65 years than for those younger than 65 years (relative risk, 1.5). This finding agrees with findings of other studies, which suggests that, in particular, young patients benefit from HTO.^8-11

Moreover, there is a clear relation between HTO survival and obesity. In a study of 159 CWHTOs, Akizuki and colleagues¹² reported that preoperative body mass index (BMI) higher than 27.5 kg/m² was a significant risk factor for early failure. Using BMI higher than 30 kg/m² as a threshold, Howells and colleagues⁹ found significantly inferior Knee Society Score (KSS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) results for the obese group 5 years after HTO.

Radiographic evidence of severe preoperative compartment degeneration has been associated with early conversion to TKA. Flecher and colleagues¹¹ and van Raaij and colleagues¹³ both concluded the best long-term survival grades are achieved in HTO patients with mild compartment OA (Ahlbäck^14 grade I). The question then becomes whether these patients should be treated nonoperatively instead.^15,16The literature supports strict adherence to inclusion criteria in the selection of a potential HTO candidate. Age, BMI, and the preoperative state of OA should be taken into account in order to optimize clinical outcome and survivorship results in patients about to undergo HTO.

Outcomes

Multiple authors have described or compared the midterm or long-term results of the various surgical HTO techniques. Howells and colleagues⁹ noted overall survival rates of 87% (5 years after CWHTO) and 79% (10 years after CWHTO). Over the 10-year postoperative period, there was significant deterioration in clinical outcome scores and survivorship. Others authors have had similar findings.^17-19 van Raaij and colleagues¹³ found that the 10-year probability of survival after CWHTO was 75%. In 455 patients who underwent lateral CWHTO, Hui and colleagues⁸ found that 5-year probability of survival was 95%, 10-year probability was 79%, and 15-year probability was 56%. Niinimäki and colleagues¹⁰ used the Finnish Arthroplasty Register to report HTO survivorship at a national level. Using conversion to TKA as a cutoff, they noted 5-year survivorship of 89% and 10-year survivorship of 73%. To our knowledge, 2 groups, both in Japan, have reported substantially higher 15-year survival rates: 90%¹² and 93%.²⁰ The authors acknowledged that their results were significantly better than in other countries and that Japanese lifestyle, culture, and body habitus therefore require further investigation. At this time, it is not possible to compare their results with Western results.

In an attempt to compare the different survival rates of the various HTO techniques, Schallberger and colleagues²¹ conducted a retrospective study of OWHTOs and CWHTOs. At median follow-up of 16.5 years, comparative survival rates showed a trend of deterioration. Although data were limited, there were no significant differences in survival or functional outcome between the 2 techniques. In a recent randomized clinical trial, Duivenvoorden and colleagues⁵ compared these techniques’ midterm results (mean follow-up, 6 years). Clinical outcomes were not significantly different. There were more complications in the OWHTO group and more conversions to TKA in the CWHTO group. Considering these results, the authors suggested OWHTO without autologous bone graft is the best HTO treatment strategy for medial gonarthritis with varus malalignment of <12°.

The HTO results noted in these studies show a similar deteriorating trend; expected 10-year survivorship is 75%. Although modern implants and surgical techniques are being used, evidence supporting use of one surgical HTO method over another is lacking.

UKA for Medial Compartment OA

Indications

Since it was first introduced in the 1970s, use of UKA for single-compartment OA has been a subject of debate. The high failure rates reported at the time raised skepticism about the new treatment.²² Kozinn and Scott²³ defined classic indications and contraindications. Indications included isolated medial or lateral compartment OA or osteonecrosis of the knee, age over 60 years, and weight under 82 kg. In addition, the angular deformity of the affected lower extremity had to be <15° and passively correctable to neutral at time of surgery. Last, the flexion contracture had to be <5°, and ideal ROM was 90°. Contraindications included high activity, age under 60 years, and inflammatory arthritis. Strict adherence led to improved implant survival and lower revision rates. Because of improved surgical techniques, modern implant designs, and accumulating experience with the procedure, the surgical indications for UKA have expanded. Exact thresholds for UKA inclusion, however, remain unclear.

The modern literature is overturning the traditional idea that UKA is not indicated for patients under age 60 years.²³ Using KSS, Thompson and colleagues²⁴ found that younger patients did better than older patients 2 years after UKA using various types of implants. Analyzing survivorship results, Heyse and colleagues²⁵ concluded that UKA can be successful in patients under age 60 years and reported a 15-year survivorship rate of 85.6% and excellent outcome scores. Other authors have had similar findings.^26-28

Evaluating the influence of weight, Thompson and colleagues²⁴ found obese patients did not have a higher revision rate but did have slower progression of improvement 2 years after UKA. Cavaignac and colleagues²⁹ concluded that, at minimum follow-up of 7 years (range, 7-22 years), weight did not influence UKA survivorship. Other authors^30-33 have found no significant influence of BMI on survival.

Reports on preoperative radiographic parameters that can potentially influence UKA results are limited. In 113 medial UKAs studied by Niinimäki and colleagues,³⁴ mild medial compartment degeneration, seen on preoperative radiographs, was associated with significantly higher failure rates. The authors concluded that other treatment options should be favored in the absence of severe isolated compartment OA.

Although the classic indications defined by Kozinn and Scott²³ have yielded good to excellent UKA results, improvements in implants and surgical techniques^35-38 have extended the criteria. The modern literature demonstrates that age and BMI should not be used as criteria for excluding UKA candidates. Radiographically, there should be significant isolated compartment degeneration in order to optimize patient-reported outcome and survivorship.

Outcomes

Improved implant designs and modern minimally invasive techniques have effected a change in outcome results and a renewed interest in implants. Over the past decade, multiple authors have described the various modern UKA implants and their survivorship. Reports published since UKA was introduced in the 1970s show a continual increase in implant survival. Koskinen and colleagues,³⁹ using Finnish Arthroplasty Register data on 1819 UKAs performed between 1985 and 2003, found 10-year survival rates of 81% for Oxford implants (Zimmer Biomet), 79% for Miller-Galante II (Zimmer Biomet), 78% for Duracon (Howmedica), and 53% for PCA unicompartmental knee (Howmedica). Heyse and colleagues²⁵ reported 10- and 15-year survivorship data (93.5% and 86.3%, respectively) for 223 patients under age 60 years at the time of their index surgery (Genesis Unicondylar implant, Smith & Nephew), performed between 1993 and 2005. KSS was good to excellent. Similar numbers in cohorts under age 60 years were reported by Schai and colleagues²⁶ using the PFC system (Johnson & Johnson) and by Price and colleagues²⁷ using the medial Oxford UKA. Both groups reported excellent survivorship rates: 93% at 2- to 6-year follow-up and 91% at 10-year follow-up. The outcome in older patients seems satisfactory as well. In another multicenter report, by Price and colleagues,⁴⁰ medial Oxford UKAs had a 15-year survival rate of 93%. Berger and colleagues⁴¹ reported similar numbers for the Miller-Galante prosthesis. Survival rates were 98% (10 years) and 95.7% (13 years), and 92% of patients had good to excellent Hospital for Special Surgery knee scores.

Although various modern implants have had good to excellent results, the historical question of what type of UKA to use (mobile or fixed-bearing) remains unanswered. To try to address it, Peersman and colleagues⁴² performed a systematic review of 44 papers (9463 knees). The 2 implant types had comparable revision rates. Another recent retrospective study tried to determine what is crucial for implant survival: implant design or surgeon experience.⁴³ The authors concluded that prosthetic component positioning is key. Other authors have reported high-volume centers are crucial for satisfactory UKA results and lower revision rates.^44-46

Results of these studies indicate that, where UKAs are being performed in volume, 10-year survivorship rates higher than 90% and good to excellent outcomes can be expected.

UKA vs HTO

Cohort studies that have directly compared the 2 treatment modalities are scarce, and most have been retrospective. In a prospective study, Stukenborg-Colsman and colleagues⁴⁷ randomized patients with medial compartment OA to undergo either CWHTO (32 patients) with a technique reported by Coventry⁴⁸ or UKA (28 patients) with the unicondylar knee sliding prosthesis, Tübingen pattern (Aesculap), between 1988 and 1991. Patients were assessed 2.5, 4.5, and 7.5 years after surgery. More postoperative complications were noted in the HTO group. At 7- to 10-year follow-up, 71% of the HTO group and 65% of the UKA group had excellent KSS. Mean ROM was 103° after UKA (range, 35°-140°) and 117° after HTO (range, 85°-135°) during the same assessment. Although differences were not significant, Kaplan-Meier survival analysis was 60% for HTO and 77% for UKA at 10 years. Results were not promising for the implants used, compared with other implants, but the authors concluded that, because of improvements in implant designs and image-guided techniques, better long-term success can be expected with UKA than with HTO.

In another prospective study, Börjesson and colleagues⁴⁹ evaluated pain during walking, ROM, British Orthopaedic Association (BOA) scores, and gait variables at 1- and 5-year follow-up. Patients with moderate medial OA (Ahlbäck¹⁴ grade I-III) were randomly selected to undergo CWHTO or UKA (Brigham, DePuy). There were no significant differences in BOA scores, ROM, or pain during walking between the 2 groups at 3 months, 1 year, and 5 years after surgery. Gait analysis showed a significant difference in favor of UKA only at 3 months after surgery. At 1- and 5-year follow-up, no significant differences were noted.

To clarify current ambiguities, Fu and colleagues⁵⁰ performed a systematic review of all (11) comparative studies. These studies had a total of 5840 (5081 UKA, 759 HTO) patients. Although ROM was significantly better for the HTO group than the UKA group, the UKA group had significantly better functional results. Walking after surgery was significantly faster for the UKA group. The authors suggested the difference might be attributed to the different postoperative regimens—HTO patients wore a whole-leg plaster cast for 6 weeks, and UKA patients were allowed immediate postoperative weight-bearing. Regarding rates of survival and complications, pooled data showed no significant differences. Despite these results, the authors acknowledged the limitation of available randomized clinical trials and the multiple techniques and implants used. We share their assertion that larger prospective controlled trials are needed. These are crucial to getting a definitive answer regarding which of the 2 treatment strategies should be used for isolated compartment OA.

Current Trends in Use of UKA and HTO

Evaluation of national registries and recent reports showed a global shift in use of both HTO and UKA. Despite the lack of national HTO registries, a few reports have described use of TKA, UKA, and HTO in Western populations over the past 2 decades. Using 1998-2007 data from the Swedish Knee Arthroplasty Register, W-Dahl and colleagues⁵¹ found a 3-fold increase in UKA use, whereas HTO use was halved over the same period. Niinimäki and colleagues⁵² reported similar findings with the Finnish National Hospital Discharge Register. They noted a steady 6.8% annual decrease in osteotomies, whereas UKA use increased sharply after the Oxford UKA was introduced (Phase 3; Biomet). These findings are consistent with several reports from North America. In their epidemiologic analysis covering the period 1985-1990, Wright and colleagues⁵³ found an 11% to 14% annual decrease in osteotomies among the elderly, compared with an annual decrease of only 3% to 4% among patients younger than 65 years. Nwachukwu and colleagues⁵⁴ recently compared UKA and HTO practice patterns between 2007 and 2011, using data from a large US private payer insurance database. They noted an annual growth rate of 4.7% in UKA use, compared with an annual 3.9% decrease in HTO use. Furthermore, based on their subgroup analysis, they speculated there was a demographic shift toward UKA, as opposed to TKA, particularly in older women. Bolognesi and colleagues⁵⁵ investigated further. Evaluating all Medicare beneficiaries who underwent knee arthroplasty in the United States between 2000 and 2009, they noted a 1.7-fold increase in TKA use and a 6.2-fold increase in UKA use. As there were no substantial changes in patient characteristics over that period, the authors hypothesized that a possible broadening of inclusion criteria may have led to the increased use of UKA.

There is a possible multifactorial explanation for the current global shift in favor of UKA. First, UKA was once a technically demanding procedure, but improved surgical techniques, image guidance, and robot assistance⁵⁶ have made it relatively less difficult. Second, UKA surgery is associated with lower reported perioperative morbidities.⁵⁷ We think these factors have contributed to the global trend of less HTO use and more UKA use in the treatment of unicompartmental OA.

Conclusion

The modern literature suggests the inclusion criteria for HTO have been well investigated and defined; the UKA criteria remain a matter of debate but seem to be expanding. Long-term survival results seem to favor UKA, though patient satisfaction with both procedures is good to excellent. The broadening range of inclusion criteria and consistent reports of durable outcomes, coupled with excellent patient satisfaction, likely explain the shift toward UKA in the treatment of isolated compartment degeneration.

Am J Orthop. 2016;45(6):E355-E361. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

An increasingly number of patients with symptomatic isolated medial unicompartmental knee osteoarthritis (OA) are too young and too functionally active to be ideal candidates for total knee arthroplasty (TKA). Isolated medial compartment OA occurs in 10% to 29.5% of all cases, whereas the isolated lateral variant is less common, with a reported incidence of 1% to 7%.^1,2 In 1961, Jackson and Waugh³ introduced the high tibial osteotomy (HTO) as a surgical treatment for single-compartment OA. This procedure is designed to increase the life span of articular cartilage by unloading and redistributing the mechanical forces over the nonaffected compartment. Unicompartmental knee arthroplasty (UKA) was introduced in the 1970s as an alternative to TKA or HTO for single-compartment OA.

Since the introduction of these methods, there has been debate about which patients are appropriate candidates for each procedure. Improved surgical techniques and implant designs have led surgeons to reexamine the selection criteria and contraindications for these procedures. Furthermore, given the increasing popularity and use of UKA, the question arises as to whether HTO still has a role in clinical practice in the surgical treatment of medial OA of the knee.

To clarify current ambiguities, we review the modern indications, subjective outcome scores, and survivorship results of UKA and HTO in the treatment of isolated medial compartment degeneration of the knee. In addition, in a thorough review of the literature, we evaluate global trends in the use of both methods.

High Tibial Osteotomy for Medial Compartment OA

Indications

Before the introduction of TKA and UKA for single-compartment OA, surgical management consisted of HTO. When the mechanical axis is slightly overcorrected, the medial compartment is decompressed, ensuring tissue viability and delaying progressive compartment degeneration.

Traditionally, HTO is indicated for young (age <60 years), normal-weight, active patients with radiographic single-compartment OA.⁶ The knee should be stable and have good range of motion (ROM; flexion >120°), and pain should be localized to the tibiofemoral joint line.

Over the past few decades, numerous authors have reported similar inclusion criteria, clarifying their definition. This definition should be further refined in order to optimize survivorship and clinical outcomes.

Confirming age as an inclusion criterion for HTO, Trieb and colleagues⁷ found that the risk of failure was significantly (P = .046) higher for HTO patients older than 65 years than for those younger than 65 years (relative risk, 1.5). This finding agrees with findings of other studies, which suggests that, in particular, young patients benefit from HTO.^8-11

Moreover, there is a clear relation between HTO survival and obesity. In a study of 159 CWHTOs, Akizuki and colleagues¹² reported that preoperative body mass index (BMI) higher than 27.5 kg/m² was a significant risk factor for early failure. Using BMI higher than 30 kg/m² as a threshold, Howells and colleagues⁹ found significantly inferior Knee Society Score (KSS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) results for the obese group 5 years after HTO.

Radiographic evidence of severe preoperative compartment degeneration has been associated with early conversion to TKA. Flecher and colleagues¹¹ and van Raaij and colleagues¹³ both concluded the best long-term survival grades are achieved in HTO patients with mild compartment OA (Ahlbäck^14 grade I). The question then becomes whether these patients should be treated nonoperatively instead.^15,16The literature supports strict adherence to inclusion criteria in the selection of a potential HTO candidate. Age, BMI, and the preoperative state of OA should be taken into account in order to optimize clinical outcome and survivorship results in patients about to undergo HTO.

Outcomes

Multiple authors have described or compared the midterm or long-term results of the various surgical HTO techniques. Howells and colleagues⁹ noted overall survival rates of 87% (5 years after CWHTO) and 79% (10 years after CWHTO). Over the 10-year postoperative period, there was significant deterioration in clinical outcome scores and survivorship. Others authors have had similar findings.^17-19 van Raaij and colleagues¹³ found that the 10-year probability of survival after CWHTO was 75%. In 455 patients who underwent lateral CWHTO, Hui and colleagues⁸ found that 5-year probability of survival was 95%, 10-year probability was 79%, and 15-year probability was 56%. Niinimäki and colleagues¹⁰ used the Finnish Arthroplasty Register to report HTO survivorship at a national level. Using conversion to TKA as a cutoff, they noted 5-year survivorship of 89% and 10-year survivorship of 73%. To our knowledge, 2 groups, both in Japan, have reported substantially higher 15-year survival rates: 90%¹² and 93%.²⁰ The authors acknowledged that their results were significantly better than in other countries and that Japanese lifestyle, culture, and body habitus therefore require further investigation. At this time, it is not possible to compare their results with Western results.

In an attempt to compare the different survival rates of the various HTO techniques, Schallberger and colleagues²¹ conducted a retrospective study of OWHTOs and CWHTOs. At median follow-up of 16.5 years, comparative survival rates showed a trend of deterioration. Although data were limited, there were no significant differences in survival or functional outcome between the 2 techniques. In a recent randomized clinical trial, Duivenvoorden and colleagues⁵ compared these techniques’ midterm results (mean follow-up, 6 years). Clinical outcomes were not significantly different. There were more complications in the OWHTO group and more conversions to TKA in the CWHTO group. Considering these results, the authors suggested OWHTO without autologous bone graft is the best HTO treatment strategy for medial gonarthritis with varus malalignment of <12°.

The HTO results noted in these studies show a similar deteriorating trend; expected 10-year survivorship is 75%. Although modern implants and surgical techniques are being used, evidence supporting use of one surgical HTO method over another is lacking.

UKA for Medial Compartment OA

Indications

Since it was first introduced in the 1970s, use of UKA for single-compartment OA has been a subject of debate. The high failure rates reported at the time raised skepticism about the new treatment.²² Kozinn and Scott²³ defined classic indications and contraindications. Indications included isolated medial or lateral compartment OA or osteonecrosis of the knee, age over 60 years, and weight under 82 kg. In addition, the angular deformity of the affected lower extremity had to be <15° and passively correctable to neutral at time of surgery. Last, the flexion contracture had to be <5°, and ideal ROM was 90°. Contraindications included high activity, age under 60 years, and inflammatory arthritis. Strict adherence led to improved implant survival and lower revision rates. Because of improved surgical techniques, modern implant designs, and accumulating experience with the procedure, the surgical indications for UKA have expanded. Exact thresholds for UKA inclusion, however, remain unclear.

The modern literature is overturning the traditional idea that UKA is not indicated for patients under age 60 years.²³ Using KSS, Thompson and colleagues²⁴ found that younger patients did better than older patients 2 years after UKA using various types of implants. Analyzing survivorship results, Heyse and colleagues²⁵ concluded that UKA can be successful in patients under age 60 years and reported a 15-year survivorship rate of 85.6% and excellent outcome scores. Other authors have had similar findings.^26-28

Evaluating the influence of weight, Thompson and colleagues²⁴ found obese patients did not have a higher revision rate but did have slower progression of improvement 2 years after UKA. Cavaignac and colleagues²⁹ concluded that, at minimum follow-up of 7 years (range, 7-22 years), weight did not influence UKA survivorship. Other authors^30-33 have found no significant influence of BMI on survival.

Reports on preoperative radiographic parameters that can potentially influence UKA results are limited. In 113 medial UKAs studied by Niinimäki and colleagues,³⁴ mild medial compartment degeneration, seen on preoperative radiographs, was associated with significantly higher failure rates. The authors concluded that other treatment options should be favored in the absence of severe isolated compartment OA.

Although the classic indications defined by Kozinn and Scott²³ have yielded good to excellent UKA results, improvements in implants and surgical techniques^35-38 have extended the criteria. The modern literature demonstrates that age and BMI should not be used as criteria for excluding UKA candidates. Radiographically, there should be significant isolated compartment degeneration in order to optimize patient-reported outcome and survivorship.

Outcomes

Improved implant designs and modern minimally invasive techniques have effected a change in outcome results and a renewed interest in implants. Over the past decade, multiple authors have described the various modern UKA implants and their survivorship. Reports published since UKA was introduced in the 1970s show a continual increase in implant survival. Koskinen and colleagues,³⁹ using Finnish Arthroplasty Register data on 1819 UKAs performed between 1985 and 2003, found 10-year survival rates of 81% for Oxford implants (Zimmer Biomet), 79% for Miller-Galante II (Zimmer Biomet), 78% for Duracon (Howmedica), and 53% for PCA unicompartmental knee (Howmedica). Heyse and colleagues²⁵ reported 10- and 15-year survivorship data (93.5% and 86.3%, respectively) for 223 patients under age 60 years at the time of their index surgery (Genesis Unicondylar implant, Smith & Nephew), performed between 1993 and 2005. KSS was good to excellent. Similar numbers in cohorts under age 60 years were reported by Schai and colleagues²⁶ using the PFC system (Johnson & Johnson) and by Price and colleagues²⁷ using the medial Oxford UKA. Both groups reported excellent survivorship rates: 93% at 2- to 6-year follow-up and 91% at 10-year follow-up. The outcome in older patients seems satisfactory as well. In another multicenter report, by Price and colleagues,⁴⁰ medial Oxford UKAs had a 15-year survival rate of 93%. Berger and colleagues⁴¹ reported similar numbers for the Miller-Galante prosthesis. Survival rates were 98% (10 years) and 95.7% (13 years), and 92% of patients had good to excellent Hospital for Special Surgery knee scores.

Although various modern implants have had good to excellent results, the historical question of what type of UKA to use (mobile or fixed-bearing) remains unanswered. To try to address it, Peersman and colleagues⁴² performed a systematic review of 44 papers (9463 knees). The 2 implant types had comparable revision rates. Another recent retrospective study tried to determine what is crucial for implant survival: implant design or surgeon experience.⁴³ The authors concluded that prosthetic component positioning is key. Other authors have reported high-volume centers are crucial for satisfactory UKA results and lower revision rates.^44-46

Results of these studies indicate that, where UKAs are being performed in volume, 10-year survivorship rates higher than 90% and good to excellent outcomes can be expected.

UKA vs HTO

Cohort studies that have directly compared the 2 treatment modalities are scarce, and most have been retrospective. In a prospective study, Stukenborg-Colsman and colleagues⁴⁷ randomized patients with medial compartment OA to undergo either CWHTO (32 patients) with a technique reported by Coventry⁴⁸ or UKA (28 patients) with the unicondylar knee sliding prosthesis, Tübingen pattern (Aesculap), between 1988 and 1991. Patients were assessed 2.5, 4.5, and 7.5 years after surgery. More postoperative complications were noted in the HTO group. At 7- to 10-year follow-up, 71% of the HTO group and 65% of the UKA group had excellent KSS. Mean ROM was 103° after UKA (range, 35°-140°) and 117° after HTO (range, 85°-135°) during the same assessment. Although differences were not significant, Kaplan-Meier survival analysis was 60% for HTO and 77% for UKA at 10 years. Results were not promising for the implants used, compared with other implants, but the authors concluded that, because of improvements in implant designs and image-guided techniques, better long-term success can be expected with UKA than with HTO.

In another prospective study, Börjesson and colleagues⁴⁹ evaluated pain during walking, ROM, British Orthopaedic Association (BOA) scores, and gait variables at 1- and 5-year follow-up. Patients with moderate medial OA (Ahlbäck¹⁴ grade I-III) were randomly selected to undergo CWHTO or UKA (Brigham, DePuy). There were no significant differences in BOA scores, ROM, or pain during walking between the 2 groups at 3 months, 1 year, and 5 years after surgery. Gait analysis showed a significant difference in favor of UKA only at 3 months after surgery. At 1- and 5-year follow-up, no significant differences were noted.

To clarify current ambiguities, Fu and colleagues⁵⁰ performed a systematic review of all (11) comparative studies. These studies had a total of 5840 (5081 UKA, 759 HTO) patients. Although ROM was significantly better for the HTO group than the UKA group, the UKA group had significantly better functional results. Walking after surgery was significantly faster for the UKA group. The authors suggested the difference might be attributed to the different postoperative regimens—HTO patients wore a whole-leg plaster cast for 6 weeks, and UKA patients were allowed immediate postoperative weight-bearing. Regarding rates of survival and complications, pooled data showed no significant differences. Despite these results, the authors acknowledged the limitation of available randomized clinical trials and the multiple techniques and implants used. We share their assertion that larger prospective controlled trials are needed. These are crucial to getting a definitive answer regarding which of the 2 treatment strategies should be used for isolated compartment OA.

Current Trends in Use of UKA and HTO

Evaluation of national registries and recent reports showed a global shift in use of both HTO and UKA. Despite the lack of national HTO registries, a few reports have described use of TKA, UKA, and HTO in Western populations over the past 2 decades. Using 1998-2007 data from the Swedish Knee Arthroplasty Register, W-Dahl and colleagues⁵¹ found a 3-fold increase in UKA use, whereas HTO use was halved over the same period. Niinimäki and colleagues⁵² reported similar findings with the Finnish National Hospital Discharge Register. They noted a steady 6.8% annual decrease in osteotomies, whereas UKA use increased sharply after the Oxford UKA was introduced (Phase 3; Biomet). These findings are consistent with several reports from North America. In their epidemiologic analysis covering the period 1985-1990, Wright and colleagues⁵³ found an 11% to 14% annual decrease in osteotomies among the elderly, compared with an annual decrease of only 3% to 4% among patients younger than 65 years. Nwachukwu and colleagues⁵⁴ recently compared UKA and HTO practice patterns between 2007 and 2011, using data from a large US private payer insurance database. They noted an annual growth rate of 4.7% in UKA use, compared with an annual 3.9% decrease in HTO use. Furthermore, based on their subgroup analysis, they speculated there was a demographic shift toward UKA, as opposed to TKA, particularly in older women. Bolognesi and colleagues⁵⁵ investigated further. Evaluating all Medicare beneficiaries who underwent knee arthroplasty in the United States between 2000 and 2009, they noted a 1.7-fold increase in TKA use and a 6.2-fold increase in UKA use. As there were no substantial changes in patient characteristics over that period, the authors hypothesized that a possible broadening of inclusion criteria may have led to the increased use of UKA.

There is a possible multifactorial explanation for the current global shift in favor of UKA. First, UKA was once a technically demanding procedure, but improved surgical techniques, image guidance, and robot assistance⁵⁶ have made it relatively less difficult. Second, UKA surgery is associated with lower reported perioperative morbidities.⁵⁷ We think these factors have contributed to the global trend of less HTO use and more UKA use in the treatment of unicompartmental OA.

Conclusion

The modern literature suggests the inclusion criteria for HTO have been well investigated and defined; the UKA criteria remain a matter of debate but seem to be expanding. Long-term survival results seem to favor UKA, though patient satisfaction with both procedures is good to excellent. The broadening range of inclusion criteria and consistent reports of durable outcomes, coupled with excellent patient satisfaction, likely explain the shift toward UKA in the treatment of isolated compartment degeneration.

Am J Orthop. 2016;45(6):E355-E361. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Football is an important component of American culture, with approximately 3 million youth athletes, 1.1 million high school athletes, and 100,000 college athletes participating each year.¹ Participation in football provides athletes with physical, social, psychological, and academic benefits. Despite these benefits, widespread focus has been placed on the safety of football due to the risk for sport-related concussion (SRC) and potentially long-term effects; however, little recognition has been given to the advancements in concussion management across time and occurrence of concussions during most life activities. Although it is reasonable for concerns to be presented, it is important to better understand SRC and the current factors leading to prolonged recoveries, increased risk for injury, and potentially long-term effects.

What Is a Concussion?

Concussions occur after sustaining direct or indirect injury to the head or other parts of the body, as long as the injury force is transmitted to the head. Athletes often experience physical, cognitive, emotional, and sleep-related symptoms post-concussion secondary to an “energy crisis” within the brain.² The energy crisis occurs as the result of transient neurological dysfunction triggered by changes in the brain (eg, release of neurotransmitters, impaired axonal function).^2,3 Concussion is undetectable with traditional imaging; however, advanced imaging techniques (eg, diffuse tensor imaging) have shown progress in assessing axonal injury.³ Symptom duration post-concussion is highly variable due to individual differences; a recent study showed recovery took 3 to 4 weeks for memory and symptoms.^4,5

Previous Concussion Management

Identification techniques and return-to-play guidelines for concussion have significantly changed across time. In the past, concussion grading scales were utilized for diagnosis and return to play was possible within the same contest.^6,7 It has since been recognized that initial concussion severity makes it difficult to predict recovery.³ For example, research revealed memory decline and increased symptoms 36 hours post-injury for athletes with a grade 1 concussion (ie, transient confusion, no loss of consciousness, concussion symptoms or mental status changes that resolve within 15 minutes of injury) compared to baseline.⁷ Another study found duration of mental status changes to be related to slower symptom resolution and memory impairment 36 hours to 7 days post-injury.⁶ Consequently, return to play within the same contest was likely too liberal. Guidelines today recommend immediate removal from play with suspected SRC. Nevertheless, the “play through pain” culture has led athletes to continue playing after SRC, contributing to prolonged recoveries and potentially long-term effects.

Current Concussion Management: Continued Concerns and Areas of Improvement

Despite increased awareness of concussions, recent estimates revealed high rates (ie, 27:1 ratio for general players) of underreporting in college football, particularly amongst offensive linemen.⁸ Researchers have studied recovery implications for remaining in play, with one study revealing a 2.2 times greater risk for prolonged recovery in college athletes with delayed vs immediate removal.⁹ Another similar study discovered an 8.8 times greater risk for prolonged recovery in adolescent and young adult athletes not removed vs removed from play.¹⁰ Further analysis found remaining in play to be the greatest risk factor for prolonged recovery compared to other previously studied risk factors (eg, age, sex, posttraumatic migraine).¹⁰ Additionally, significant differences in neurocognitive data were seen between the “removed” and “not removed” groups for verbal memory, visual memory, processing speed, and reaction time at 1 to 7 days and 8 to 30 days.¹⁰ The recovery implications of remaining in play and the additional risk for second impact syndrome (SIS), or repeat concussion when recovering from another injury, emphasizes the need for further education efforts amongst athletes to encourage immediate reporting of injury.¹¹

Sideline Assessment

Sideline assessment has become a vital component of concussion management to rule out concussion and/or significant injury other than concussion. Assessment should include observation, cognitive/balance testing, neurologic examination, and possible exertion testing to ensure a comprehensive evaluation of all areas of potential dysfunction.¹² Indications for emergency department evaluation include suspicion for cervical spine injury, intracranial hemorrhage, or skull fracture as well as prolonged loss of consciousness, high-risk mechanisms, posttraumatic seizure(s), and/or significant worsening of symptoms.¹²

Observation

On the sideline, it is important to identify any immediate signs of injury (ie, loss of consciousness, anterograde/retrograde amnesia, and disorientation/confusion). Since immediate signs are not always present, it is important to be aware of the most commonly reported symptoms, including headache, difficulty concentrating, fatigue, drowsiness, and dizziness.¹³ If symptoms are not reported by the athlete, balance problems, lack of coordination, increased emotionality, and difficulty following instructions may be observed during play.¹²

On-Field Assessment

Cognitive and balance testing are essential in determining if an athlete has sustained a concussion. Immediate declines in memory, concentration abilities, and balance abilities are common. Given limitations in administering long testing batteries on the sideline, brief standardized tests such as the Standardized Assessment of Concussion (SAC), Balance Error Scoring System (BESS), and Sport Concussion Assessment Tool (SCAT) are commonly utilized. Identification of cognitive and/or balance abnormalities can help the athlete recognize deficits following injury.¹² Balance problems are experienced due to abnormalities in sensory organization and generally resolve during the acute recovery period.^14,15 Cognitive difficulties typically persist longer than balance problems, though duration varies widely.

Neurologic Evaluation

A neurologic evaluation including cranial nerve testing and evaluation of motor-sensory function (ie, assessment for the strength and sensation of upper and lower extremities) is important to identify focal deficits (ie, sensation changes, loss of fine motor control) indicative of serious intracranial pathology.¹² Additionally, clinicians have suggested inclusion of vestibular and oculomotor assessments due to frequent dysfunction post-concussion.^12,15,16 Examination of the vestibular/oculomotor systems through tools such as the Vestibular/Ocular Motor Screening (VOMS) assessment (assesses both the vestibular and oculomotor systems) and King-Devick Test (primarily assesses saccadic eye movements) can elicit symptoms that may not present immediately. If assessment appears normal, exertion testing can be utilized to determine if symptoms are provoked through physical exercise that should include cardio, dynamic, and sport-specific activities to stress the vestibular system.¹²

Risk Factors for Injury and Prolonged Recovery

Medical professionals must consider the presence of risk factors when managing concussion in order to make appropriate treatment recommendations and return-to-play decisions. Research has demonstrated the role of female gender, learning disability, attention-deficit/hyperactivity disorder, psychiatric history, young age, motion sickness, sleep problems, somatization, concussion history, on-field dizziness, posttraumatic migraine, and fogginess in increased risk for injury and/or prolonged recovery.^17-25 Additionally, athletes with ongoing symptoms from a previous injury are at risk for sustaining another injury.

Acute Home Concussion Management

Although strict rest has been recommended post-concussion, recent research evaluating strict rest vs usual care for adolescents revealed greater symptom reports and longer recovery periods for the strict rest group.²⁶ Based on these findings and emphasis for regulation within the migraine literature (due to the common pathophysiology between migraine and concussion²⁷), we recommend that athletes follow a regulated daily schedule post-concussion including: 1) regular sleep-wake schedule with avoidance of naps, 2) regular meals, 3) adequate fluid hydration, 4) light noncontact physical activity (ie, walking, with progressions recommended by a physician), and 5) stress management techniques. Use of these strategies immediately can help in preventing against increased symptoms and stress, and decreases the need for medication in select cases. Additionally, over-the-counter medications should be limited to 2 to 3 doses per week to avoid rebound headaches.²⁸

In-Office Concussion Management

Athletes diagnosed with SRC will experience different symptoms based on the injury mechanism, risk factors, and management approach. Comprehensive evaluation should include assessment of risk factors, injury details, symptoms, neurocognitive functioning, vestibular/oculomotor dysfunction, tolerance of physical exertion, balance functioning, and cervical spine integrity (if necessary).^29,30 Due to individual differences and the heterogeneous symptom profiles, concussion management must move beyond a “one size fits all” approach to avoid nonspecific treatment strategies and consequently prolonged recoveries.²⁹ Clinicians and researchers at University of Pittsburgh Medical Center have identified 6 concussion clinical profiles (ie, vestibular, ocular, posttraumatic migraine, cervical, anxiety/mood, and cognitive/fatigue) that are generally identifiable 48 hours after injury.^29,30 Identification of the clinical profile(s) through a comprehensive evaluation guides the development of individualized treatment plans and targeted rehabilitation strategies.^29,30

Vestibular. The vestibular system is responsible for stabilizing vision while the head moves and balance control.¹⁵ Athletes can experience central and/or peripheral vestibular dysfunction to include benign paroxysmal positional vertigo (BPPV), visual motion sensitivity, vestibular ocular reflex impairment, and balance impairment.^30,31 Symptoms typically include dizziness, impaired balance, blurry vision, difficulty focusing, and environmental sensitivity.^15,29,30 Potential treatment options include vestibular rehabilitation, exertion therapy, and school/work accommodations.

Ocular. The oculomotor system is responsible for control of eye movements. Athletes can experience many different posttraumatic vision changes, including convergence problems, eye-tracking difficulties, refractive error, difficulty with pursuits/saccades, and accommodation insufficiency. Symptoms typically include light sensitivity, blurred vision, double vision, headaches, fatigue, and memory difficulties.^15,29,30 Potential treatment options include vision therapy, vestibular rehabilitation, and school/work accommodations.³²

Posttraumatic Migraine. Headache, the most common post-concussion symptom, can persist and meet criteria for posttraumatic migraine (ie, unilateral headache with accompanying nausea and/or photophobia and phonophobia).^29,30,33 Implementation of a routine schedule, daily physical activity, exertion therapy, pharmacologic intervention, and school/work accommodations are potential treatment options.

Cervical. The cervical spine can be injured during whiplash-type injuries. Therefore, determining the location, onset, and typical exacerbations of pain can be helpful in identifying cervical involvement.^29,30 Symptoms typically include headaches, neck pain, numbness, and tingling. Evaluation and therapy by a certified physical therapist and pharmacologic intervention (eg, muscle relaxants) are potential treatment options. ^29,30

Anxiety/Mood. Anxiety, or worry and fear about everyday situations, is common post-concussion and can sometimes be related to ongoing vestibular impairment. Symptoms typically include ruminative thoughts, avoidance of specific situations, hypervigilance, feelings of being overwhelmed, and difficulty falling asleep.^29,30 Potential treatment options include implementation of a routine schedule, exposure to provocative situations, psychotherapy, pharmacologic intervention, and school/work accommodations.³⁴

Conclusion

Advancements in SRC management warrant change in the conversations regarding concussion in football. Specifically, conversations should address the current understanding of concussion and improvements in the safety of football through stricter concussion guidelines, detailed sideline evaluations, recognition of risk factors, improved acute management, and identification of concussion profiles that help to direct individualized treatment plans and targeted rehabilitation strategies. The biggest concerns related to concussions in football include underreporting of injury, premature return to play, and receiving routine rather than individualized treatment. Therefore, to further improve the safety of football and management of concussion it is essential that future efforts focus on the following 6 areas:

Education: Improved understanding of concussion is imperative to reducing poor outcomes and widespread concerns.

Immediate reporting: Reporting of concussion must be expected and encouraged through consistent responses by coaches to reduce underreporting and fear of reporting in athletes.

Prevention techniques: Athletes must be taught proper form and playing techniques to reduce the risk for concussion. Proper form and technique should be incentivized.

Targeted treatment: Individualized treatment plans and targeted rehabilitation strategies must be developed based on the identified clinical profile(s) to avoid nonspecific treatment recommendations.

Multidisciplinary treatment teams: Given the heterogeneous symptoms profiles and need for care provided by different medical specialties, multidisciplinary teams are essential.

Remain current: With the progress in understanding concussion, providers must remain vigilant of future advances in concussion management to further improve the safety of football.

Am J Orthop. 2016;45(6):352-356. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Football is an important component of American culture, with approximately 3 million youth athletes, 1.1 million high school athletes, and 100,000 college athletes participating each year.¹ Participation in football provides athletes with physical, social, psychological, and academic benefits. Despite these benefits, widespread focus has been placed on the safety of football due to the risk for sport-related concussion (SRC) and potentially long-term effects; however, little recognition has been given to the advancements in concussion management across time and occurrence of concussions during most life activities. Although it is reasonable for concerns to be presented, it is important to better understand SRC and the current factors leading to prolonged recoveries, increased risk for injury, and potentially long-term effects.

What Is a Concussion?

Concussions occur after sustaining direct or indirect injury to the head or other parts of the body, as long as the injury force is transmitted to the head. Athletes often experience physical, cognitive, emotional, and sleep-related symptoms post-concussion secondary to an “energy crisis” within the brain.² The energy crisis occurs as the result of transient neurological dysfunction triggered by changes in the brain (eg, release of neurotransmitters, impaired axonal function).^2,3 Concussion is undetectable with traditional imaging; however, advanced imaging techniques (eg, diffuse tensor imaging) have shown progress in assessing axonal injury.³ Symptom duration post-concussion is highly variable due to individual differences; a recent study showed recovery took 3 to 4 weeks for memory and symptoms.^4,5

Previous Concussion Management

Identification techniques and return-to-play guidelines for concussion have significantly changed across time. In the past, concussion grading scales were utilized for diagnosis and return to play was possible within the same contest.^6,7 It has since been recognized that initial concussion severity makes it difficult to predict recovery.³ For example, research revealed memory decline and increased symptoms 36 hours post-injury for athletes with a grade 1 concussion (ie, transient confusion, no loss of consciousness, concussion symptoms or mental status changes that resolve within 15 minutes of injury) compared to baseline.⁷ Another study found duration of mental status changes to be related to slower symptom resolution and memory impairment 36 hours to 7 days post-injury.⁶ Consequently, return to play within the same contest was likely too liberal. Guidelines today recommend immediate removal from play with suspected SRC. Nevertheless, the “play through pain” culture has led athletes to continue playing after SRC, contributing to prolonged recoveries and potentially long-term effects.

Current Concussion Management: Continued Concerns and Areas of Improvement

Despite increased awareness of concussions, recent estimates revealed high rates (ie, 27:1 ratio for general players) of underreporting in college football, particularly amongst offensive linemen.⁸ Researchers have studied recovery implications for remaining in play, with one study revealing a 2.2 times greater risk for prolonged recovery in college athletes with delayed vs immediate removal.⁹ Another similar study discovered an 8.8 times greater risk for prolonged recovery in adolescent and young adult athletes not removed vs removed from play.¹⁰ Further analysis found remaining in play to be the greatest risk factor for prolonged recovery compared to other previously studied risk factors (eg, age, sex, posttraumatic migraine).¹⁰ Additionally, significant differences in neurocognitive data were seen between the “removed” and “not removed” groups for verbal memory, visual memory, processing speed, and reaction time at 1 to 7 days and 8 to 30 days.¹⁰ The recovery implications of remaining in play and the additional risk for second impact syndrome (SIS), or repeat concussion when recovering from another injury, emphasizes the need for further education efforts amongst athletes to encourage immediate reporting of injury.¹¹

Sideline Assessment

Sideline assessment has become a vital component of concussion management to rule out concussion and/or significant injury other than concussion. Assessment should include observation, cognitive/balance testing, neurologic examination, and possible exertion testing to ensure a comprehensive evaluation of all areas of potential dysfunction.¹² Indications for emergency department evaluation include suspicion for cervical spine injury, intracranial hemorrhage, or skull fracture as well as prolonged loss of consciousness, high-risk mechanisms, posttraumatic seizure(s), and/or significant worsening of symptoms.¹²

Observation

On the sideline, it is important to identify any immediate signs of injury (ie, loss of consciousness, anterograde/retrograde amnesia, and disorientation/confusion). Since immediate signs are not always present, it is important to be aware of the most commonly reported symptoms, including headache, difficulty concentrating, fatigue, drowsiness, and dizziness.¹³ If symptoms are not reported by the athlete, balance problems, lack of coordination, increased emotionality, and difficulty following instructions may be observed during play.¹²

On-Field Assessment

Cognitive and balance testing are essential in determining if an athlete has sustained a concussion. Immediate declines in memory, concentration abilities, and balance abilities are common. Given limitations in administering long testing batteries on the sideline, brief standardized tests such as the Standardized Assessment of Concussion (SAC), Balance Error Scoring System (BESS), and Sport Concussion Assessment Tool (SCAT) are commonly utilized. Identification of cognitive and/or balance abnormalities can help the athlete recognize deficits following injury.¹² Balance problems are experienced due to abnormalities in sensory organization and generally resolve during the acute recovery period.^14,15 Cognitive difficulties typically persist longer than balance problems, though duration varies widely.

Neurologic Evaluation

A neurologic evaluation including cranial nerve testing and evaluation of motor-sensory function (ie, assessment for the strength and sensation of upper and lower extremities) is important to identify focal deficits (ie, sensation changes, loss of fine motor control) indicative of serious intracranial pathology.¹² Additionally, clinicians have suggested inclusion of vestibular and oculomotor assessments due to frequent dysfunction post-concussion.^12,15,16 Examination of the vestibular/oculomotor systems through tools such as the Vestibular/Ocular Motor Screening (VOMS) assessment (assesses both the vestibular and oculomotor systems) and King-Devick Test (primarily assesses saccadic eye movements) can elicit symptoms that may not present immediately. If assessment appears normal, exertion testing can be utilized to determine if symptoms are provoked through physical exercise that should include cardio, dynamic, and sport-specific activities to stress the vestibular system.¹²

Risk Factors for Injury and Prolonged Recovery

Medical professionals must consider the presence of risk factors when managing concussion in order to make appropriate treatment recommendations and return-to-play decisions. Research has demonstrated the role of female gender, learning disability, attention-deficit/hyperactivity disorder, psychiatric history, young age, motion sickness, sleep problems, somatization, concussion history, on-field dizziness, posttraumatic migraine, and fogginess in increased risk for injury and/or prolonged recovery.^17-25 Additionally, athletes with ongoing symptoms from a previous injury are at risk for sustaining another injury.

Acute Home Concussion Management

Although strict rest has been recommended post-concussion, recent research evaluating strict rest vs usual care for adolescents revealed greater symptom reports and longer recovery periods for the strict rest group.²⁶ Based on these findings and emphasis for regulation within the migraine literature (due to the common pathophysiology between migraine and concussion²⁷), we recommend that athletes follow a regulated daily schedule post-concussion including: 1) regular sleep-wake schedule with avoidance of naps, 2) regular meals, 3) adequate fluid hydration, 4) light noncontact physical activity (ie, walking, with progressions recommended by a physician), and 5) stress management techniques. Use of these strategies immediately can help in preventing against increased symptoms and stress, and decreases the need for medication in select cases. Additionally, over-the-counter medications should be limited to 2 to 3 doses per week to avoid rebound headaches.²⁸

In-Office Concussion Management

Athletes diagnosed with SRC will experience different symptoms based on the injury mechanism, risk factors, and management approach. Comprehensive evaluation should include assessment of risk factors, injury details, symptoms, neurocognitive functioning, vestibular/oculomotor dysfunction, tolerance of physical exertion, balance functioning, and cervical spine integrity (if necessary).^29,30 Due to individual differences and the heterogeneous symptom profiles, concussion management must move beyond a “one size fits all” approach to avoid nonspecific treatment strategies and consequently prolonged recoveries.²⁹ Clinicians and researchers at University of Pittsburgh Medical Center have identified 6 concussion clinical profiles (ie, vestibular, ocular, posttraumatic migraine, cervical, anxiety/mood, and cognitive/fatigue) that are generally identifiable 48 hours after injury.^29,30 Identification of the clinical profile(s) through a comprehensive evaluation guides the development of individualized treatment plans and targeted rehabilitation strategies.^29,30

Vestibular. The vestibular system is responsible for stabilizing vision while the head moves and balance control.¹⁵ Athletes can experience central and/or peripheral vestibular dysfunction to include benign paroxysmal positional vertigo (BPPV), visual motion sensitivity, vestibular ocular reflex impairment, and balance impairment.^30,31 Symptoms typically include dizziness, impaired balance, blurry vision, difficulty focusing, and environmental sensitivity.^15,29,30 Potential treatment options include vestibular rehabilitation, exertion therapy, and school/work accommodations.

Ocular. The oculomotor system is responsible for control of eye movements. Athletes can experience many different posttraumatic vision changes, including convergence problems, eye-tracking difficulties, refractive error, difficulty with pursuits/saccades, and accommodation insufficiency. Symptoms typically include light sensitivity, blurred vision, double vision, headaches, fatigue, and memory difficulties.^15,29,30 Potential treatment options include vision therapy, vestibular rehabilitation, and school/work accommodations.³²

Posttraumatic Migraine. Headache, the most common post-concussion symptom, can persist and meet criteria for posttraumatic migraine (ie, unilateral headache with accompanying nausea and/or photophobia and phonophobia).^29,30,33 Implementation of a routine schedule, daily physical activity, exertion therapy, pharmacologic intervention, and school/work accommodations are potential treatment options.

Cervical. The cervical spine can be injured during whiplash-type injuries. Therefore, determining the location, onset, and typical exacerbations of pain can be helpful in identifying cervical involvement.^29,30 Symptoms typically include headaches, neck pain, numbness, and tingling. Evaluation and therapy by a certified physical therapist and pharmacologic intervention (eg, muscle relaxants) are potential treatment options. ^29,30

Anxiety/Mood. Anxiety, or worry and fear about everyday situations, is common post-concussion and can sometimes be related to ongoing vestibular impairment. Symptoms typically include ruminative thoughts, avoidance of specific situations, hypervigilance, feelings of being overwhelmed, and difficulty falling asleep.^29,30 Potential treatment options include implementation of a routine schedule, exposure to provocative situations, psychotherapy, pharmacologic intervention, and school/work accommodations.³⁴

Conclusion

Advancements in SRC management warrant change in the conversations regarding concussion in football. Specifically, conversations should address the current understanding of concussion and improvements in the safety of football through stricter concussion guidelines, detailed sideline evaluations, recognition of risk factors, improved acute management, and identification of concussion profiles that help to direct individualized treatment plans and targeted rehabilitation strategies. The biggest concerns related to concussions in football include underreporting of injury, premature return to play, and receiving routine rather than individualized treatment. Therefore, to further improve the safety of football and management of concussion it is essential that future efforts focus on the following 6 areas:

Education: Improved understanding of concussion is imperative to reducing poor outcomes and widespread concerns.

Immediate reporting: Reporting of concussion must be expected and encouraged through consistent responses by coaches to reduce underreporting and fear of reporting in athletes.

Prevention techniques: Athletes must be taught proper form and playing techniques to reduce the risk for concussion. Proper form and technique should be incentivized.

Targeted treatment: Individualized treatment plans and targeted rehabilitation strategies must be developed based on the identified clinical profile(s) to avoid nonspecific treatment recommendations.

Multidisciplinary treatment teams: Given the heterogeneous symptoms profiles and need for care provided by different medical specialties, multidisciplinary teams are essential.

Remain current: With the progress in understanding concussion, providers must remain vigilant of future advances in concussion management to further improve the safety of football.

Am J Orthop. 2016;45(6):352-356. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Football is an important component of American culture, with approximately 3 million youth athletes, 1.1 million high school athletes, and 100,000 college athletes participating each year.¹ Participation in football provides athletes with physical, social, psychological, and academic benefits. Despite these benefits, widespread focus has been placed on the safety of football due to the risk for sport-related concussion (SRC) and potentially long-term effects; however, little recognition has been given to the advancements in concussion management across time and occurrence of concussions during most life activities. Although it is reasonable for concerns to be presented, it is important to better understand SRC and the current factors leading to prolonged recoveries, increased risk for injury, and potentially long-term effects.

What Is a Concussion?

Concussions occur after sustaining direct or indirect injury to the head or other parts of the body, as long as the injury force is transmitted to the head. Athletes often experience physical, cognitive, emotional, and sleep-related symptoms post-concussion secondary to an “energy crisis” within the brain.² The energy crisis occurs as the result of transient neurological dysfunction triggered by changes in the brain (eg, release of neurotransmitters, impaired axonal function).^2,3 Concussion is undetectable with traditional imaging; however, advanced imaging techniques (eg, diffuse tensor imaging) have shown progress in assessing axonal injury.³ Symptom duration post-concussion is highly variable due to individual differences; a recent study showed recovery took 3 to 4 weeks for memory and symptoms.^4,5

Previous Concussion Management

Identification techniques and return-to-play guidelines for concussion have significantly changed across time. In the past, concussion grading scales were utilized for diagnosis and return to play was possible within the same contest.^6,7 It has since been recognized that initial concussion severity makes it difficult to predict recovery.³ For example, research revealed memory decline and increased symptoms 36 hours post-injury for athletes with a grade 1 concussion (ie, transient confusion, no loss of consciousness, concussion symptoms or mental status changes that resolve within 15 minutes of injury) compared to baseline.⁷ Another study found duration of mental status changes to be related to slower symptom resolution and memory impairment 36 hours to 7 days post-injury.⁶ Consequently, return to play within the same contest was likely too liberal. Guidelines today recommend immediate removal from play with suspected SRC. Nevertheless, the “play through pain” culture has led athletes to continue playing after SRC, contributing to prolonged recoveries and potentially long-term effects.

Current Concussion Management: Continued Concerns and Areas of Improvement

Despite increased awareness of concussions, recent estimates revealed high rates (ie, 27:1 ratio for general players) of underreporting in college football, particularly amongst offensive linemen.⁸ Researchers have studied recovery implications for remaining in play, with one study revealing a 2.2 times greater risk for prolonged recovery in college athletes with delayed vs immediate removal.⁹ Another similar study discovered an 8.8 times greater risk for prolonged recovery in adolescent and young adult athletes not removed vs removed from play.¹⁰ Further analysis found remaining in play to be the greatest risk factor for prolonged recovery compared to other previously studied risk factors (eg, age, sex, posttraumatic migraine).¹⁰ Additionally, significant differences in neurocognitive data were seen between the “removed” and “not removed” groups for verbal memory, visual memory, processing speed, and reaction time at 1 to 7 days and 8 to 30 days.¹⁰ The recovery implications of remaining in play and the additional risk for second impact syndrome (SIS), or repeat concussion when recovering from another injury, emphasizes the need for further education efforts amongst athletes to encourage immediate reporting of injury.¹¹

Sideline Assessment

Sideline assessment has become a vital component of concussion management to rule out concussion and/or significant injury other than concussion. Assessment should include observation, cognitive/balance testing, neurologic examination, and possible exertion testing to ensure a comprehensive evaluation of all areas of potential dysfunction.¹² Indications for emergency department evaluation include suspicion for cervical spine injury, intracranial hemorrhage, or skull fracture as well as prolonged loss of consciousness, high-risk mechanisms, posttraumatic seizure(s), and/or significant worsening of symptoms.¹²

Observation

On the sideline, it is important to identify any immediate signs of injury (ie, loss of consciousness, anterograde/retrograde amnesia, and disorientation/confusion). Since immediate signs are not always present, it is important to be aware of the most commonly reported symptoms, including headache, difficulty concentrating, fatigue, drowsiness, and dizziness.¹³ If symptoms are not reported by the athlete, balance problems, lack of coordination, increased emotionality, and difficulty following instructions may be observed during play.¹²

On-Field Assessment

Cognitive and balance testing are essential in determining if an athlete has sustained a concussion. Immediate declines in memory, concentration abilities, and balance abilities are common. Given limitations in administering long testing batteries on the sideline, brief standardized tests such as the Standardized Assessment of Concussion (SAC), Balance Error Scoring System (BESS), and Sport Concussion Assessment Tool (SCAT) are commonly utilized. Identification of cognitive and/or balance abnormalities can help the athlete recognize deficits following injury.¹² Balance problems are experienced due to abnormalities in sensory organization and generally resolve during the acute recovery period.^14,15 Cognitive difficulties typically persist longer than balance problems, though duration varies widely.

Neurologic Evaluation

A neurologic evaluation including cranial nerve testing and evaluation of motor-sensory function (ie, assessment for the strength and sensation of upper and lower extremities) is important to identify focal deficits (ie, sensation changes, loss of fine motor control) indicative of serious intracranial pathology.¹² Additionally, clinicians have suggested inclusion of vestibular and oculomotor assessments due to frequent dysfunction post-concussion.^12,15,16 Examination of the vestibular/oculomotor systems through tools such as the Vestibular/Ocular Motor Screening (VOMS) assessment (assesses both the vestibular and oculomotor systems) and King-Devick Test (primarily assesses saccadic eye movements) can elicit symptoms that may not present immediately. If assessment appears normal, exertion testing can be utilized to determine if symptoms are provoked through physical exercise that should include cardio, dynamic, and sport-specific activities to stress the vestibular system.¹²

Risk Factors for Injury and Prolonged Recovery

Medical professionals must consider the presence of risk factors when managing concussion in order to make appropriate treatment recommendations and return-to-play decisions. Research has demonstrated the role of female gender, learning disability, attention-deficit/hyperactivity disorder, psychiatric history, young age, motion sickness, sleep problems, somatization, concussion history, on-field dizziness, posttraumatic migraine, and fogginess in increased risk for injury and/or prolonged recovery.^17-25 Additionally, athletes with ongoing symptoms from a previous injury are at risk for sustaining another injury.

Acute Home Concussion Management

Although strict rest has been recommended post-concussion, recent research evaluating strict rest vs usual care for adolescents revealed greater symptom reports and longer recovery periods for the strict rest group.²⁶ Based on these findings and emphasis for regulation within the migraine literature (due to the common pathophysiology between migraine and concussion²⁷), we recommend that athletes follow a regulated daily schedule post-concussion including: 1) regular sleep-wake schedule with avoidance of naps, 2) regular meals, 3) adequate fluid hydration, 4) light noncontact physical activity (ie, walking, with progressions recommended by a physician), and 5) stress management techniques. Use of these strategies immediately can help in preventing against increased symptoms and stress, and decreases the need for medication in select cases. Additionally, over-the-counter medications should be limited to 2 to 3 doses per week to avoid rebound headaches.²⁸

In-Office Concussion Management

Athletes diagnosed with SRC will experience different symptoms based on the injury mechanism, risk factors, and management approach. Comprehensive evaluation should include assessment of risk factors, injury details, symptoms, neurocognitive functioning, vestibular/oculomotor dysfunction, tolerance of physical exertion, balance functioning, and cervical spine integrity (if necessary).^29,30 Due to individual differences and the heterogeneous symptom profiles, concussion management must move beyond a “one size fits all” approach to avoid nonspecific treatment strategies and consequently prolonged recoveries.²⁹ Clinicians and researchers at University of Pittsburgh Medical Center have identified 6 concussion clinical profiles (ie, vestibular, ocular, posttraumatic migraine, cervical, anxiety/mood, and cognitive/fatigue) that are generally identifiable 48 hours after injury.^29,30 Identification of the clinical profile(s) through a comprehensive evaluation guides the development of individualized treatment plans and targeted rehabilitation strategies.^29,30

Vestibular. The vestibular system is responsible for stabilizing vision while the head moves and balance control.¹⁵ Athletes can experience central and/or peripheral vestibular dysfunction to include benign paroxysmal positional vertigo (BPPV), visual motion sensitivity, vestibular ocular reflex impairment, and balance impairment.^30,31 Symptoms typically include dizziness, impaired balance, blurry vision, difficulty focusing, and environmental sensitivity.^15,29,30 Potential treatment options include vestibular rehabilitation, exertion therapy, and school/work accommodations.

Ocular. The oculomotor system is responsible for control of eye movements. Athletes can experience many different posttraumatic vision changes, including convergence problems, eye-tracking difficulties, refractive error, difficulty with pursuits/saccades, and accommodation insufficiency. Symptoms typically include light sensitivity, blurred vision, double vision, headaches, fatigue, and memory difficulties.^15,29,30 Potential treatment options include vision therapy, vestibular rehabilitation, and school/work accommodations.³²

Posttraumatic Migraine. Headache, the most common post-concussion symptom, can persist and meet criteria for posttraumatic migraine (ie, unilateral headache with accompanying nausea and/or photophobia and phonophobia).^29,30,33 Implementation of a routine schedule, daily physical activity, exertion therapy, pharmacologic intervention, and school/work accommodations are potential treatment options.

Cervical. The cervical spine can be injured during whiplash-type injuries. Therefore, determining the location, onset, and typical exacerbations of pain can be helpful in identifying cervical involvement.^29,30 Symptoms typically include headaches, neck pain, numbness, and tingling. Evaluation and therapy by a certified physical therapist and pharmacologic intervention (eg, muscle relaxants) are potential treatment options. ^29,30

Anxiety/Mood. Anxiety, or worry and fear about everyday situations, is common post-concussion and can sometimes be related to ongoing vestibular impairment. Symptoms typically include ruminative thoughts, avoidance of specific situations, hypervigilance, feelings of being overwhelmed, and difficulty falling asleep.^29,30 Potential treatment options include implementation of a routine schedule, exposure to provocative situations, psychotherapy, pharmacologic intervention, and school/work accommodations.³⁴

Conclusion

Advancements in SRC management warrant change in the conversations regarding concussion in football. Specifically, conversations should address the current understanding of concussion and improvements in the safety of football through stricter concussion guidelines, detailed sideline evaluations, recognition of risk factors, improved acute management, and identification of concussion profiles that help to direct individualized treatment plans and targeted rehabilitation strategies. The biggest concerns related to concussions in football include underreporting of injury, premature return to play, and receiving routine rather than individualized treatment. Therefore, to further improve the safety of football and management of concussion it is essential that future efforts focus on the following 6 areas:

Education: Improved understanding of concussion is imperative to reducing poor outcomes and widespread concerns.

Immediate reporting: Reporting of concussion must be expected and encouraged through consistent responses by coaches to reduce underreporting and fear of reporting in athletes.

Prevention techniques: Athletes must be taught proper form and playing techniques to reduce the risk for concussion. Proper form and technique should be incentivized.

Targeted treatment: Individualized treatment plans and targeted rehabilitation strategies must be developed based on the identified clinical profile(s) to avoid nonspecific treatment recommendations.

Multidisciplinary treatment teams: Given the heterogeneous symptoms profiles and need for care provided by different medical specialties, multidisciplinary teams are essential.

Remain current: With the progress in understanding concussion, providers must remain vigilant of future advances in concussion management to further improve the safety of football.

Am J Orthop. 2016;45(6):352-356. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Football, one of the most popular sports in the United States, is additionally recognized as a leading contributor to sports injury secondary to the contact collision nature of the endeavor. There are an estimated 1.1 million high school football players with another 100,000 participants combined in the National Football League (NFL), college, junior college, Arena Football League, and semipro levels of play.¹ USA Football estimates that an additional 3 million youth participate in community football leagues.¹ The National Center for Catastrophic Sports Injury Research recently calculated a fatality rate of 0.14 per 100,000 participants in 2014 for the 4.2 million who play football at all levels—and 0.45 per 100,000 in high school.¹ While direct deaths from head and spine injury remain a significant contributor to the number of catastrophic injuries, indirect deaths (systemic failure) predominate. Exertional heat stroke (EHS) has emerged as one of the leading indirect causes of death in high school and collegiate football. Boden and colleagues² reported that high school and college football players sustain approximately 12 fatalities annually, with indirect systemic causes being twice as common as direct blunt trauma.²The most common indirect causes identified included cardiac failure, heat illness, and complications of sickle cell trait (SCT). It was also noted that the risk of SCT, heat-related, and cardiac deaths increased during the second decade of the study, indicating these conditions may require a greater emphasis on diagnosis, treatment, and prevention. This review details for the team physician the unique challenge of exercising in the heat to the football player, and the prevention, diagnosis, management and return-to-play issues pertinent to exertional heat illness (EHI).

The Challenge

EHS represents the most severe manifestation of EHI—a gamut of diseases commonly encountered during the hot summer months when American football season begins. The breadth of EHI includes several important clinical diagnoses: exercise-associated muscle cramps (heat cramps); heat exhaustion with and without syncope; heat injury with evidence of end organ injury (eg, rhabdomyolysis); and EHS. EHS is defined as “a form of hyperthermia associated with a systemic inflammatory response leading to a syndrome of multi-organ dysfunction in which encephalopathy predominates.”³ EHS, if left untreated, or even if clinical treatment is delayed, may result in significant end organ morbidity and/or mortality.

During exercise, the human thermoregulatory system mitigates heat gain by increasing skin blood flow and sweating, causing an increased dissipation of heat to the surrounding environment by leveraging conduction, convection, and evaporation.^4,5 Elevated environmental temperatures, increased humidity, and dehydration can impede the body’s ability to dissipate heat at a rate needed to maintain thermoregulation. This imbalance can result in hyperthermia secondary to uncompensated heat stress,⁵ which in turn can lead to EHI. Football players have unique challenges that make them particularly vulnerable to EHI. The summer heat during early-season participation and the requirement for equipment that covers nearly 60% of body surfaces pose increased risk of volume losses and hyperthermia that trigger the onset of EHI.⁶ Football athletes’ body compositions and physical size are additional contributing risk factors; the relatively high muscle and fat content increase thermogenicity, which require their bodies to dissipate more heat.⁷

An estimated 9000 cases of EHI occur annually across all high school sports,⁸ with an incidence of 1.6:100,000 athlete-exposures.^8,9 Studies have demonstrated, however, that EHI occurs in football 11.4 times more often than in all other high school sports combined.¹⁰ The incidence of nonfatal EHI in all levels of football is 4.42-5:100,000.^8,9 Between 2000 and 2014, 41 football players died from EHS.¹ In football, approximately 75% of all EHI events occurred during practices, while only 25% of incidents occurred during games.⁸

Given these potentially deadly consequences, it is important that football team physicians are not only alert to the early symptoms of heat illness and prepared to intervene to prevent the progression to EHS, but are critical leaders in educating coaches and players in evidence-based EHI prevention practices and policies.

Prevention

EHS is a preventable condition, arguably the most common cause of preventable nontraumatic exertional death in young athletes in the United States. Close attention to mitigating risk factors should begin prior to the onset of preseason practice and continue through the early season, where athletes are at the highest risk of developing heat illness.

Primary Prevention

Primary prevention is fundamental to minimizing the occurrences of EHI. It focuses on the following methods: recognition of inherent risk factors, acclimatization, hydration, and avoidance of inciting substances (including supplements).

Pre-Participation Examination. The purpose of the pre-participation examination (PPE) is to maximize an athlete’s safety by identifying medical conditions that place the athlete at risk.^11,12 The Preparticipation Physical Evaluation, 4th edition, the most widely used consensus publication, specifically queries if an athlete has a previous history of heat injury. However, it only indirectly addresses intrinsic risk factors that may predispose an athlete to EHI who has never had an EHI before. Therefore, providers should take the opportunity of the PPE to inquire about additional risk factors that may make an athlete high risk for sustaining a heat injury. Common risk factors for EHI are listed in Table 1.

Secondary Prevention

Despite physicians’ best efforts to prevent all cases of EHI, athletes will still experience the effects of exercise-induced hyperthermia. The goal of secondary prevention is to slow the progression of this hyperthermia so that it does not progress to more dangerous EHI.

Hydration. Dehydration is an important risk factor for EHI. Sweat maintains thermoregulation by dissipating heat generated during exercise; however, it also contributes to body water losses. Furthermore, intravascular depletion decreases stroke volume, thereby increasing cardiovascular strain. It is estimated that for every 1% loss in body mass from dehydration, body temperature rises 0.22°C in comparison to a euhydrated state.⁶ Dehydration occurs more rapidly in hot environments, as fluid is lost through increased sweat production.⁷ After approximately 6% to 10% body weight volume loss, cardiac output cannot be maintained, diminishing sweat production and blood flow to both skin and muscle and causing diminished performance and a significant risk of heat exhaustion.⁷ If left unchecked, these physiologic changes result in further elevations in body temperature and increased cardiovascular strain, ultimately placing the athlete at significant risk for development of EHS.

Adequate hydration to maintain euvolemia is an important step in avoiding possible EHI. Multiple studies have shown that football players experience a baseline hypovolemia during their competition season,⁶ a deficit that is most marked during the first week of practices.¹⁷ This deficit is multifactorial, as football players expend a significant amount of fluid through sweat, are not able to adequately replace these losses during practice, and do not appropriately hydrate off the field.^6,18 Some players, especially linemen, sweat at a higher rate than their teammates, posing a possible risk of significant dehydration.⁶ Coaches and players alike should be educated on the importance of adequate hydration to meet their fluid needs.

The goal of hydration during exercise is to prevent large fluid losses that can adversely affect performance and increase risk of EHI;⁶ it may be unrealistic to replace all fluid losses during the practice period. Instead, athletes should target complete volume replacement over the post-exercise period.⁶ Some recommend hydrating based upon thirst drive; however, thirst is activated following a volume loss of approximately 2% body mass, the same degree of losses that place athletes at an increased risk for performance impairment and EHI.^4,6,11,12 Individuals should have access to fluids throughout practice and competition and be encouraged to hydrate as needed.^6,12,15 Furthermore, staff should modify their practices based upon WBGT and acclimatization status to provide more frequent hydration breaks.

Hyperhydration and Salt Intake. Of note, there are inherent risks to hyperhydration. Athletes with low sweat rates have an increased risk of overhydration and the development of exercise-associated hyponatremia (EAH),⁶ a condition whose presentation is very similar to EHS. In addition, inadequate sodium intake and excessive sweating can also contribute to the development of EAH. EAH has been implicated in the deaths of 2 football players in 2014.^1,6 Establishing team hydration guidelines and educating players and staff on appropriate hydration and dietary salt intake is essential to reduce the risk of both dehydration and hyperhydration and their complications.⁶Intra-Event Cooling. During exercise, team physicians can employ strategies for cooling athletes during exertion to mitigate their risk of EHI by decreasing thermal and cardiovascular strain.^4,19 Cooling during exercise is hypothesized to allow for accelerated heat dissipation, where heat is lost from the body more effectively. This accelerated loss enables athletes to maintain a higher heat storage capacity over the duration of exercise, avoiding uncompensated heat stresses that ultimately cause EHI.¹⁹

Some intra-event cooling strategies include the use of cooling garments, cooling packs, and cold water/slurry ingestion. Cooling garments lower skin temperature, which in turn can decrease thermoregulatory strains;⁴ a recent meta-analysis of intra-event cooling modalities revealed that wearing an ice vest during exercise resulted in the greatest decrease in thermal heat strain.¹⁹ Internal cooling strategies—namely ingestion of cold fluids/ice slurry—have shown some mild benefit in decreasing internal temperatures; however, some studies have demonstrated some decrease in sweat production associated with cold oral intake used in isolation.¹⁹ Overall, studies have shown that combining external (cooling clothing, ice packs, fanning) and internal (cold water, ice slurry) cooling methods result in a greater cooling effect than a use of a single method.⁴

Tertiary Prevention

The goal of tertiary prevention is to mitigate the risk of long-term adverse outcomes following an EHS event. The most effective means of reducing risk for morbidity and mortality is rapid identification and treatment of EHS as well as close evaluation of an athlete’s return to activity in heat. This process is spearheaded by an effective and well-rehearsed emergency action plan.

Diagnosis and Management

Rapid identification and treatment of EHS is crucial to minimizing the risk of poor outcomes.⁷ Any delay in the treatment of EHS can dramatically increase the likelihood of associated morbidity and mortality.²⁰

EHS is diagnosed by an elevated rectal temperature ≥40°C (104°F) and associated central nervous system (CNS) dysfunction.²¹ EHS should be strongly suspected in any athlete exercising in heat who exhibits signs of CNS dysfunction, including disorientation, confusion, dizziness, erratic behavior, irritability, headache, loss of coordination, delirium, collapse, or seizures.^7,12,15 EHS may also present with symptoms of heat exhaustion, including fatigue, hyperventilation, tachycardia, vomiting, diarrhea, and hypotension.^7,12,15

Rectal temperature should be taken for any athlete with suspected EHS, as other modalities—oral, skin, axillary, and aural—can be inaccurate and easily modified by ambient confounders such as ambient and skin temperature, athlete hyperventilation, and consumption of liquids.^7,11,12 Athletes exhibiting CNS symptoms with moderately elevated rectal temperatures that do not exceed 40°C should also be assumed to be suffering from EHS and treated with rapid cooling.¹¹ On the other hand, athletes with CNS symptoms who are normothermic should be assumed to have EAH until ruled out by electrolyte assessment; IV fluids should be at no more than keep vein open (KVO) pending this determination.¹¹ In some cases, an athlete may initially present with altered mental status but return to “normal.” However, this improvement may represent a “lucid period”; evaluation should continue with rectal temperature and treatment, as EHS in these cases may progress quickly.¹⁵

Treatment is centered on rapid, whole body cooling initiated at the first sign of heat illness.^7,22 The goal of treatment is to achieve a rectal temperature <38.9°C within 30 minutes of the onset of EHS.¹⁵ Upon diagnosis, the athlete should be quickly placed in a tub of ice water to facilitate cold water immersion (CWI) therapy. Some guidelines suggest the athlete’s clothing be removed to potentiate evaporative cooling during CWI;¹² however, cooling should not be delayed due to difficulties in removing equipment. CWI, where a heat stroke victim is submerged in ice water up to their neck while water is continuously circulated, is generally considered to be the gold standard treatment as it is the modality with the highest recorded cooling rates and the lowest rate of morbidity and mortality.^7,20,21 Multiple studies of CWI have shown that survival nears 100% when aggressive cooling starts within 5 minutes of collapse or identification of EHS.^20,21,22

If whole body CWI is unavailable, alternative methods of rapid cooling should be employed. Partial CWI, with torso immersion being preferable to the extremities, has been shown to achieve an acceptable rate of cooling to achieve sufficient drops in internal body temperature.^20,23 However, one popular treatment—applying ice packs to the whole body, in particular to the groin and axillae—has not been shown to be sufficient to achieve standard cooling goals.²⁰ None of these methods have been shown to be as effective as CWI.²³

Intravenous access should be initiated with fluid resuscitation dictated by the provider’s assessment. Normal saline is recommended as the resuscitative fluid of choice, with the rate dictated by clinical judgment and adjusted as guided by electrolyte determination and clinical response. It cannot be overstated that in normothermic patients with confusion, EAH is the diagnosis of exclusion and aggressive fluid resuscitation should be withheld until electrolyte determination.

Once rectal temperature descends appropriately (~38.9°C), the cooling process should stop and the individual should be transported to a hospital for further observation²⁰ and evaluation of possible sequelae, including rhabdomyolysis and renal injury, cardiac dysfunction and arrhythmia, severe electrolyte abnormalities, acute respiratory distress syndrome, lactic acidosis, and other forms of end-organ failure (Figure).

Emergency Action Plan

Team physicians should be proactive in developing an emergency action plan to address possible EHS events. These plans should be site-specific, addressing procedures for all practice and home competition locations.¹² All competition venues should have a CWI tub on-site in events where there is an increased risk of EHS.^12,15,20 This tub should be set up and functional for all high-risk activities, including practices.¹²

Following recognition of a potential case of EHS, treatment teams should have procedures in place to transport athletes to the treatment area, obtain rectal temperature, initiate rapid cooling, and stabilize the athlete for transport to an emergency department (ED) for further evaluation.^12,15 A written record of treatments and medications provided during athlete stabilization should be maintained and transported with the athlete to the ED.¹⁵ A list of helpful equipment and supplies for treatment of EHS can be found in Table 5.

Return to Play

Perhaps the most challenging and important role the team physician has is determining an athlete’s return to play following EHI, as there currently are no evidence-based guidelines for return to activity for these athletes.⁷ The decisions surrounding return to play are highly individualized, as recovery from EHS and heat injury is associated with the duration of internal body temperature elevation above the critical level (40°C).^7,20 Guidelines for return to activity following recovery from EHI differ among experts and institutions.^7,25 The general consensus from these guidelines is that, at minimum, athletes should not participate in any physical activity until they are asymptomatic and all blood tests have normalized.¹¹ Following this asymptomatic period, most guidelines advocate for a slow, deliberate return to activity.¹¹ The American College of Sports Medicine (ACSM) offers one reasonable approach to the returning athlete following EHS:⁷

• No exercise for at least 7 days following release from medical care.
• Follow-up with a physician 1 week after release from medical care for physical examination and any warranted lab or radiologic studies (based upon organ systems affected during EHS).
• Once cleared to return to activity, the athlete begins exercise in a cool environment, gradually increasing the duration, intensity, and heat exposure over 2 weeks to demonstrate heat tolerance and acclimatization.
• Athletes who cannot resume vigorous activity due to recurrent symptoms (eg, excessive fatigue) should be reevaluated after 4 weeks. Laboratory exercise-heat tolerance testing may be useful in this setting.
• The athlete may resume full competition once they are able to participate in full training in the heat for 2 to 4 weeks without adverse effects.

Heat tolerance testing (HTT) in these athletes remains controversial.^{5 26} The ACSM recommends that HTT be considered only for those unable to return to vigorous activity after a suitable period (approximately 4 weeks). In contrast, the Israeli Defense Force (IDF) uses HTT to evaluate soldiers following EHS to guide decision-making about return to duty.²⁷ The IDF HTT assumes that individuals will respond differently to heat stresses. They identify individuals who are “heat intolerant” as being unable to tolerate specific heat challenges, indicated by increases in body temperature occurring more rapidly than normal responders under identical environmental and exercise conditions. However, despite being used for more than 30 years, there is no clear evidence that HTT adequately predicts who will experience subsequent episodes of EHS.

Conclusion

While the recognized cornerstone of being a team physician is the provision of medical care, the ACSM Team Physician Consensus Statement²⁸ further delineates the medical and administrative responsibilities as both (1) understanding medical management and prevention of injury and illness in athletes; and (2) awareness of or involvement in the development and rehearsal of an emergency action plan. These tenets are critical for the team physician who accepts the responsibility to cover sports at the high school level or higher. Football team physicians play an essential role in mitigating risk of EHI in their athletes. Through development and execution of both comprehensive prevention strategies and emergency action plans, physicians can work to minimize athletes’ risk of both developing and experiencing significant adverse outcomes from an EHI.

Am J Orthop. 2016;45(6):340-348. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Football, one of the most popular sports in the United States, is additionally recognized as a leading contributor to sports injury secondary to the contact collision nature of the endeavor. There are an estimated 1.1 million high school football players with another 100,000 participants combined in the National Football League (NFL), college, junior college, Arena Football League, and semipro levels of play.¹ USA Football estimates that an additional 3 million youth participate in community football leagues.¹ The National Center for Catastrophic Sports Injury Research recently calculated a fatality rate of 0.14 per 100,000 participants in 2014 for the 4.2 million who play football at all levels—and 0.45 per 100,000 in high school.¹ While direct deaths from head and spine injury remain a significant contributor to the number of catastrophic injuries, indirect deaths (systemic failure) predominate. Exertional heat stroke (EHS) has emerged as one of the leading indirect causes of death in high school and collegiate football. Boden and colleagues² reported that high school and college football players sustain approximately 12 fatalities annually, with indirect systemic causes being twice as common as direct blunt trauma.²The most common indirect causes identified included cardiac failure, heat illness, and complications of sickle cell trait (SCT). It was also noted that the risk of SCT, heat-related, and cardiac deaths increased during the second decade of the study, indicating these conditions may require a greater emphasis on diagnosis, treatment, and prevention. This review details for the team physician the unique challenge of exercising in the heat to the football player, and the prevention, diagnosis, management and return-to-play issues pertinent to exertional heat illness (EHI).

The Challenge

EHS represents the most severe manifestation of EHI—a gamut of diseases commonly encountered during the hot summer months when American football season begins. The breadth of EHI includes several important clinical diagnoses: exercise-associated muscle cramps (heat cramps); heat exhaustion with and without syncope; heat injury with evidence of end organ injury (eg, rhabdomyolysis); and EHS. EHS is defined as “a form of hyperthermia associated with a systemic inflammatory response leading to a syndrome of multi-organ dysfunction in which encephalopathy predominates.”³ EHS, if left untreated, or even if clinical treatment is delayed, may result in significant end organ morbidity and/or mortality.

During exercise, the human thermoregulatory system mitigates heat gain by increasing skin blood flow and sweating, causing an increased dissipation of heat to the surrounding environment by leveraging conduction, convection, and evaporation.^4,5 Elevated environmental temperatures, increased humidity, and dehydration can impede the body’s ability to dissipate heat at a rate needed to maintain thermoregulation. This imbalance can result in hyperthermia secondary to uncompensated heat stress,⁵ which in turn can lead to EHI. Football players have unique challenges that make them particularly vulnerable to EHI. The summer heat during early-season participation and the requirement for equipment that covers nearly 60% of body surfaces pose increased risk of volume losses and hyperthermia that trigger the onset of EHI.⁶ Football athletes’ body compositions and physical size are additional contributing risk factors; the relatively high muscle and fat content increase thermogenicity, which require their bodies to dissipate more heat.⁷

An estimated 9000 cases of EHI occur annually across all high school sports,⁸ with an incidence of 1.6:100,000 athlete-exposures.^8,9 Studies have demonstrated, however, that EHI occurs in football 11.4 times more often than in all other high school sports combined.¹⁰ The incidence of nonfatal EHI in all levels of football is 4.42-5:100,000.^8,9 Between 2000 and 2014, 41 football players died from EHS.¹ In football, approximately 75% of all EHI events occurred during practices, while only 25% of incidents occurred during games.⁸

Given these potentially deadly consequences, it is important that football team physicians are not only alert to the early symptoms of heat illness and prepared to intervene to prevent the progression to EHS, but are critical leaders in educating coaches and players in evidence-based EHI prevention practices and policies.

Prevention

EHS is a preventable condition, arguably the most common cause of preventable nontraumatic exertional death in young athletes in the United States. Close attention to mitigating risk factors should begin prior to the onset of preseason practice and continue through the early season, where athletes are at the highest risk of developing heat illness.

Primary Prevention

Primary prevention is fundamental to minimizing the occurrences of EHI. It focuses on the following methods: recognition of inherent risk factors, acclimatization, hydration, and avoidance of inciting substances (including supplements).

Pre-Participation Examination. The purpose of the pre-participation examination (PPE) is to maximize an athlete’s safety by identifying medical conditions that place the athlete at risk.^11,12 The Preparticipation Physical Evaluation, 4th edition, the most widely used consensus publication, specifically queries if an athlete has a previous history of heat injury. However, it only indirectly addresses intrinsic risk factors that may predispose an athlete to EHI who has never had an EHI before. Therefore, providers should take the opportunity of the PPE to inquire about additional risk factors that may make an athlete high risk for sustaining a heat injury. Common risk factors for EHI are listed in Table 1.

Secondary Prevention

Despite physicians’ best efforts to prevent all cases of EHI, athletes will still experience the effects of exercise-induced hyperthermia. The goal of secondary prevention is to slow the progression of this hyperthermia so that it does not progress to more dangerous EHI.

Hydration. Dehydration is an important risk factor for EHI. Sweat maintains thermoregulation by dissipating heat generated during exercise; however, it also contributes to body water losses. Furthermore, intravascular depletion decreases stroke volume, thereby increasing cardiovascular strain. It is estimated that for every 1% loss in body mass from dehydration, body temperature rises 0.22°C in comparison to a euhydrated state.⁶ Dehydration occurs more rapidly in hot environments, as fluid is lost through increased sweat production.⁷ After approximately 6% to 10% body weight volume loss, cardiac output cannot be maintained, diminishing sweat production and blood flow to both skin and muscle and causing diminished performance and a significant risk of heat exhaustion.⁷ If left unchecked, these physiologic changes result in further elevations in body temperature and increased cardiovascular strain, ultimately placing the athlete at significant risk for development of EHS.

Adequate hydration to maintain euvolemia is an important step in avoiding possible EHI. Multiple studies have shown that football players experience a baseline hypovolemia during their competition season,⁶ a deficit that is most marked during the first week of practices.¹⁷ This deficit is multifactorial, as football players expend a significant amount of fluid through sweat, are not able to adequately replace these losses during practice, and do not appropriately hydrate off the field.^6,18 Some players, especially linemen, sweat at a higher rate than their teammates, posing a possible risk of significant dehydration.⁶ Coaches and players alike should be educated on the importance of adequate hydration to meet their fluid needs.

The goal of hydration during exercise is to prevent large fluid losses that can adversely affect performance and increase risk of EHI;⁶ it may be unrealistic to replace all fluid losses during the practice period. Instead, athletes should target complete volume replacement over the post-exercise period.⁶ Some recommend hydrating based upon thirst drive; however, thirst is activated following a volume loss of approximately 2% body mass, the same degree of losses that place athletes at an increased risk for performance impairment and EHI.^4,6,11,12 Individuals should have access to fluids throughout practice and competition and be encouraged to hydrate as needed.^6,12,15 Furthermore, staff should modify their practices based upon WBGT and acclimatization status to provide more frequent hydration breaks.

Hyperhydration and Salt Intake. Of note, there are inherent risks to hyperhydration. Athletes with low sweat rates have an increased risk of overhydration and the development of exercise-associated hyponatremia (EAH),⁶ a condition whose presentation is very similar to EHS. In addition, inadequate sodium intake and excessive sweating can also contribute to the development of EAH. EAH has been implicated in the deaths of 2 football players in 2014.^1,6 Establishing team hydration guidelines and educating players and staff on appropriate hydration and dietary salt intake is essential to reduce the risk of both dehydration and hyperhydration and their complications.⁶Intra-Event Cooling. During exercise, team physicians can employ strategies for cooling athletes during exertion to mitigate their risk of EHI by decreasing thermal and cardiovascular strain.^4,19 Cooling during exercise is hypothesized to allow for accelerated heat dissipation, where heat is lost from the body more effectively. This accelerated loss enables athletes to maintain a higher heat storage capacity over the duration of exercise, avoiding uncompensated heat stresses that ultimately cause EHI.¹⁹

Some intra-event cooling strategies include the use of cooling garments, cooling packs, and cold water/slurry ingestion. Cooling garments lower skin temperature, which in turn can decrease thermoregulatory strains;⁴ a recent meta-analysis of intra-event cooling modalities revealed that wearing an ice vest during exercise resulted in the greatest decrease in thermal heat strain.¹⁹ Internal cooling strategies—namely ingestion of cold fluids/ice slurry—have shown some mild benefit in decreasing internal temperatures; however, some studies have demonstrated some decrease in sweat production associated with cold oral intake used in isolation.¹⁹ Overall, studies have shown that combining external (cooling clothing, ice packs, fanning) and internal (cold water, ice slurry) cooling methods result in a greater cooling effect than a use of a single method.⁴

Tertiary Prevention

The goal of tertiary prevention is to mitigate the risk of long-term adverse outcomes following an EHS event. The most effective means of reducing risk for morbidity and mortality is rapid identification and treatment of EHS as well as close evaluation of an athlete’s return to activity in heat. This process is spearheaded by an effective and well-rehearsed emergency action plan.

Diagnosis and Management

Rapid identification and treatment of EHS is crucial to minimizing the risk of poor outcomes.⁷ Any delay in the treatment of EHS can dramatically increase the likelihood of associated morbidity and mortality.²⁰

EHS is diagnosed by an elevated rectal temperature ≥40°C (104°F) and associated central nervous system (CNS) dysfunction.²¹ EHS should be strongly suspected in any athlete exercising in heat who exhibits signs of CNS dysfunction, including disorientation, confusion, dizziness, erratic behavior, irritability, headache, loss of coordination, delirium, collapse, or seizures.^7,12,15 EHS may also present with symptoms of heat exhaustion, including fatigue, hyperventilation, tachycardia, vomiting, diarrhea, and hypotension.^7,12,15

Rectal temperature should be taken for any athlete with suspected EHS, as other modalities—oral, skin, axillary, and aural—can be inaccurate and easily modified by ambient confounders such as ambient and skin temperature, athlete hyperventilation, and consumption of liquids.^7,11,12 Athletes exhibiting CNS symptoms with moderately elevated rectal temperatures that do not exceed 40°C should also be assumed to be suffering from EHS and treated with rapid cooling.¹¹ On the other hand, athletes with CNS symptoms who are normothermic should be assumed to have EAH until ruled out by electrolyte assessment; IV fluids should be at no more than keep vein open (KVO) pending this determination.¹¹ In some cases, an athlete may initially present with altered mental status but return to “normal.” However, this improvement may represent a “lucid period”; evaluation should continue with rectal temperature and treatment, as EHS in these cases may progress quickly.¹⁵

Treatment is centered on rapid, whole body cooling initiated at the first sign of heat illness.^7,22 The goal of treatment is to achieve a rectal temperature <38.9°C within 30 minutes of the onset of EHS.¹⁵ Upon diagnosis, the athlete should be quickly placed in a tub of ice water to facilitate cold water immersion (CWI) therapy. Some guidelines suggest the athlete’s clothing be removed to potentiate evaporative cooling during CWI;¹² however, cooling should not be delayed due to difficulties in removing equipment. CWI, where a heat stroke victim is submerged in ice water up to their neck while water is continuously circulated, is generally considered to be the gold standard treatment as it is the modality with the highest recorded cooling rates and the lowest rate of morbidity and mortality.^7,20,21 Multiple studies of CWI have shown that survival nears 100% when aggressive cooling starts within 5 minutes of collapse or identification of EHS.^20,21,22

If whole body CWI is unavailable, alternative methods of rapid cooling should be employed. Partial CWI, with torso immersion being preferable to the extremities, has been shown to achieve an acceptable rate of cooling to achieve sufficient drops in internal body temperature.^20,23 However, one popular treatment—applying ice packs to the whole body, in particular to the groin and axillae—has not been shown to be sufficient to achieve standard cooling goals.²⁰ None of these methods have been shown to be as effective as CWI.²³

Intravenous access should be initiated with fluid resuscitation dictated by the provider’s assessment. Normal saline is recommended as the resuscitative fluid of choice, with the rate dictated by clinical judgment and adjusted as guided by electrolyte determination and clinical response. It cannot be overstated that in normothermic patients with confusion, EAH is the diagnosis of exclusion and aggressive fluid resuscitation should be withheld until electrolyte determination.

Once rectal temperature descends appropriately (~38.9°C), the cooling process should stop and the individual should be transported to a hospital for further observation²⁰ and evaluation of possible sequelae, including rhabdomyolysis and renal injury, cardiac dysfunction and arrhythmia, severe electrolyte abnormalities, acute respiratory distress syndrome, lactic acidosis, and other forms of end-organ failure (Figure).

Emergency Action Plan

Team physicians should be proactive in developing an emergency action plan to address possible EHS events. These plans should be site-specific, addressing procedures for all practice and home competition locations.¹² All competition venues should have a CWI tub on-site in events where there is an increased risk of EHS.^12,15,20 This tub should be set up and functional for all high-risk activities, including practices.¹²

Following recognition of a potential case of EHS, treatment teams should have procedures in place to transport athletes to the treatment area, obtain rectal temperature, initiate rapid cooling, and stabilize the athlete for transport to an emergency department (ED) for further evaluation.^12,15 A written record of treatments and medications provided during athlete stabilization should be maintained and transported with the athlete to the ED.¹⁵ A list of helpful equipment and supplies for treatment of EHS can be found in Table 5.

Return to Play

Perhaps the most challenging and important role the team physician has is determining an athlete’s return to play following EHI, as there currently are no evidence-based guidelines for return to activity for these athletes.⁷ The decisions surrounding return to play are highly individualized, as recovery from EHS and heat injury is associated with the duration of internal body temperature elevation above the critical level (40°C).^7,20 Guidelines for return to activity following recovery from EHI differ among experts and institutions.^7,25 The general consensus from these guidelines is that, at minimum, athletes should not participate in any physical activity until they are asymptomatic and all blood tests have normalized.¹¹ Following this asymptomatic period, most guidelines advocate for a slow, deliberate return to activity.¹¹ The American College of Sports Medicine (ACSM) offers one reasonable approach to the returning athlete following EHS:⁷

• No exercise for at least 7 days following release from medical care.
• Follow-up with a physician 1 week after release from medical care for physical examination and any warranted lab or radiologic studies (based upon organ systems affected during EHS).
• Once cleared to return to activity, the athlete begins exercise in a cool environment, gradually increasing the duration, intensity, and heat exposure over 2 weeks to demonstrate heat tolerance and acclimatization.
• Athletes who cannot resume vigorous activity due to recurrent symptoms (eg, excessive fatigue) should be reevaluated after 4 weeks. Laboratory exercise-heat tolerance testing may be useful in this setting.
• The athlete may resume full competition once they are able to participate in full training in the heat for 2 to 4 weeks without adverse effects.

Heat tolerance testing (HTT) in these athletes remains controversial.^{5 26} The ACSM recommends that HTT be considered only for those unable to return to vigorous activity after a suitable period (approximately 4 weeks). In contrast, the Israeli Defense Force (IDF) uses HTT to evaluate soldiers following EHS to guide decision-making about return to duty.²⁷ The IDF HTT assumes that individuals will respond differently to heat stresses. They identify individuals who are “heat intolerant” as being unable to tolerate specific heat challenges, indicated by increases in body temperature occurring more rapidly than normal responders under identical environmental and exercise conditions. However, despite being used for more than 30 years, there is no clear evidence that HTT adequately predicts who will experience subsequent episodes of EHS.

Conclusion

While the recognized cornerstone of being a team physician is the provision of medical care, the ACSM Team Physician Consensus Statement²⁸ further delineates the medical and administrative responsibilities as both (1) understanding medical management and prevention of injury and illness in athletes; and (2) awareness of or involvement in the development and rehearsal of an emergency action plan. These tenets are critical for the team physician who accepts the responsibility to cover sports at the high school level or higher. Football team physicians play an essential role in mitigating risk of EHI in their athletes. Through development and execution of both comprehensive prevention strategies and emergency action plans, physicians can work to minimize athletes’ risk of both developing and experiencing significant adverse outcomes from an EHI.

Am J Orthop. 2016;45(6):340-348. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

Football, one of the most popular sports in the United States, is additionally recognized as a leading contributor to sports injury secondary to the contact collision nature of the endeavor. There are an estimated 1.1 million high school football players with another 100,000 participants combined in the National Football League (NFL), college, junior college, Arena Football League, and semipro levels of play.¹ USA Football estimates that an additional 3 million youth participate in community football leagues.¹ The National Center for Catastrophic Sports Injury Research recently calculated a fatality rate of 0.14 per 100,000 participants in 2014 for the 4.2 million who play football at all levels—and 0.45 per 100,000 in high school.¹ While direct deaths from head and spine injury remain a significant contributor to the number of catastrophic injuries, indirect deaths (systemic failure) predominate. Exertional heat stroke (EHS) has emerged as one of the leading indirect causes of death in high school and collegiate football. Boden and colleagues² reported that high school and college football players sustain approximately 12 fatalities annually, with indirect systemic causes being twice as common as direct blunt trauma.²The most common indirect causes identified included cardiac failure, heat illness, and complications of sickle cell trait (SCT). It was also noted that the risk of SCT, heat-related, and cardiac deaths increased during the second decade of the study, indicating these conditions may require a greater emphasis on diagnosis, treatment, and prevention. This review details for the team physician the unique challenge of exercising in the heat to the football player, and the prevention, diagnosis, management and return-to-play issues pertinent to exertional heat illness (EHI).

The Challenge

EHS represents the most severe manifestation of EHI—a gamut of diseases commonly encountered during the hot summer months when American football season begins. The breadth of EHI includes several important clinical diagnoses: exercise-associated muscle cramps (heat cramps); heat exhaustion with and without syncope; heat injury with evidence of end organ injury (eg, rhabdomyolysis); and EHS. EHS is defined as “a form of hyperthermia associated with a systemic inflammatory response leading to a syndrome of multi-organ dysfunction in which encephalopathy predominates.”³ EHS, if left untreated, or even if clinical treatment is delayed, may result in significant end organ morbidity and/or mortality.

During exercise, the human thermoregulatory system mitigates heat gain by increasing skin blood flow and sweating, causing an increased dissipation of heat to the surrounding environment by leveraging conduction, convection, and evaporation.^4,5 Elevated environmental temperatures, increased humidity, and dehydration can impede the body’s ability to dissipate heat at a rate needed to maintain thermoregulation. This imbalance can result in hyperthermia secondary to uncompensated heat stress,⁵ which in turn can lead to EHI. Football players have unique challenges that make them particularly vulnerable to EHI. The summer heat during early-season participation and the requirement for equipment that covers nearly 60% of body surfaces pose increased risk of volume losses and hyperthermia that trigger the onset of EHI.⁶ Football athletes’ body compositions and physical size are additional contributing risk factors; the relatively high muscle and fat content increase thermogenicity, which require their bodies to dissipate more heat.⁷

An estimated 9000 cases of EHI occur annually across all high school sports,⁸ with an incidence of 1.6:100,000 athlete-exposures.^8,9 Studies have demonstrated, however, that EHI occurs in football 11.4 times more often than in all other high school sports combined.¹⁰ The incidence of nonfatal EHI in all levels of football is 4.42-5:100,000.^8,9 Between 2000 and 2014, 41 football players died from EHS.¹ In football, approximately 75% of all EHI events occurred during practices, while only 25% of incidents occurred during games.⁸

Given these potentially deadly consequences, it is important that football team physicians are not only alert to the early symptoms of heat illness and prepared to intervene to prevent the progression to EHS, but are critical leaders in educating coaches and players in evidence-based EHI prevention practices and policies.

Prevention

EHS is a preventable condition, arguably the most common cause of preventable nontraumatic exertional death in young athletes in the United States. Close attention to mitigating risk factors should begin prior to the onset of preseason practice and continue through the early season, where athletes are at the highest risk of developing heat illness.

Primary Prevention

Primary prevention is fundamental to minimizing the occurrences of EHI. It focuses on the following methods: recognition of inherent risk factors, acclimatization, hydration, and avoidance of inciting substances (including supplements).

Pre-Participation Examination. The purpose of the pre-participation examination (PPE) is to maximize an athlete’s safety by identifying medical conditions that place the athlete at risk.^11,12 The Preparticipation Physical Evaluation, 4th edition, the most widely used consensus publication, specifically queries if an athlete has a previous history of heat injury. However, it only indirectly addresses intrinsic risk factors that may predispose an athlete to EHI who has never had an EHI before. Therefore, providers should take the opportunity of the PPE to inquire about additional risk factors that may make an athlete high risk for sustaining a heat injury. Common risk factors for EHI are listed in Table 1.

Secondary Prevention

Despite physicians’ best efforts to prevent all cases of EHI, athletes will still experience the effects of exercise-induced hyperthermia. The goal of secondary prevention is to slow the progression of this hyperthermia so that it does not progress to more dangerous EHI.

Hydration. Dehydration is an important risk factor for EHI. Sweat maintains thermoregulation by dissipating heat generated during exercise; however, it also contributes to body water losses. Furthermore, intravascular depletion decreases stroke volume, thereby increasing cardiovascular strain. It is estimated that for every 1% loss in body mass from dehydration, body temperature rises 0.22°C in comparison to a euhydrated state.⁶ Dehydration occurs more rapidly in hot environments, as fluid is lost through increased sweat production.⁷ After approximately 6% to 10% body weight volume loss, cardiac output cannot be maintained, diminishing sweat production and blood flow to both skin and muscle and causing diminished performance and a significant risk of heat exhaustion.⁷ If left unchecked, these physiologic changes result in further elevations in body temperature and increased cardiovascular strain, ultimately placing the athlete at significant risk for development of EHS.

Adequate hydration to maintain euvolemia is an important step in avoiding possible EHI. Multiple studies have shown that football players experience a baseline hypovolemia during their competition season,⁶ a deficit that is most marked during the first week of practices.¹⁷ This deficit is multifactorial, as football players expend a significant amount of fluid through sweat, are not able to adequately replace these losses during practice, and do not appropriately hydrate off the field.^6,18 Some players, especially linemen, sweat at a higher rate than their teammates, posing a possible risk of significant dehydration.⁶ Coaches and players alike should be educated on the importance of adequate hydration to meet their fluid needs.

The goal of hydration during exercise is to prevent large fluid losses that can adversely affect performance and increase risk of EHI;⁶ it may be unrealistic to replace all fluid losses during the practice period. Instead, athletes should target complete volume replacement over the post-exercise period.⁶ Some recommend hydrating based upon thirst drive; however, thirst is activated following a volume loss of approximately 2% body mass, the same degree of losses that place athletes at an increased risk for performance impairment and EHI.^4,6,11,12 Individuals should have access to fluids throughout practice and competition and be encouraged to hydrate as needed.^6,12,15 Furthermore, staff should modify their practices based upon WBGT and acclimatization status to provide more frequent hydration breaks.

Hyperhydration and Salt Intake. Of note, there are inherent risks to hyperhydration. Athletes with low sweat rates have an increased risk of overhydration and the development of exercise-associated hyponatremia (EAH),⁶ a condition whose presentation is very similar to EHS. In addition, inadequate sodium intake and excessive sweating can also contribute to the development of EAH. EAH has been implicated in the deaths of 2 football players in 2014.^1,6 Establishing team hydration guidelines and educating players and staff on appropriate hydration and dietary salt intake is essential to reduce the risk of both dehydration and hyperhydration and their complications.⁶Intra-Event Cooling. During exercise, team physicians can employ strategies for cooling athletes during exertion to mitigate their risk of EHI by decreasing thermal and cardiovascular strain.^4,19 Cooling during exercise is hypothesized to allow for accelerated heat dissipation, where heat is lost from the body more effectively. This accelerated loss enables athletes to maintain a higher heat storage capacity over the duration of exercise, avoiding uncompensated heat stresses that ultimately cause EHI.¹⁹

Some intra-event cooling strategies include the use of cooling garments, cooling packs, and cold water/slurry ingestion. Cooling garments lower skin temperature, which in turn can decrease thermoregulatory strains;⁴ a recent meta-analysis of intra-event cooling modalities revealed that wearing an ice vest during exercise resulted in the greatest decrease in thermal heat strain.¹⁹ Internal cooling strategies—namely ingestion of cold fluids/ice slurry—have shown some mild benefit in decreasing internal temperatures; however, some studies have demonstrated some decrease in sweat production associated with cold oral intake used in isolation.¹⁹ Overall, studies have shown that combining external (cooling clothing, ice packs, fanning) and internal (cold water, ice slurry) cooling methods result in a greater cooling effect than a use of a single method.⁴

Tertiary Prevention

The goal of tertiary prevention is to mitigate the risk of long-term adverse outcomes following an EHS event. The most effective means of reducing risk for morbidity and mortality is rapid identification and treatment of EHS as well as close evaluation of an athlete’s return to activity in heat. This process is spearheaded by an effective and well-rehearsed emergency action plan.

Diagnosis and Management

Rapid identification and treatment of EHS is crucial to minimizing the risk of poor outcomes.⁷ Any delay in the treatment of EHS can dramatically increase the likelihood of associated morbidity and mortality.²⁰

EHS is diagnosed by an elevated rectal temperature ≥40°C (104°F) and associated central nervous system (CNS) dysfunction.²¹ EHS should be strongly suspected in any athlete exercising in heat who exhibits signs of CNS dysfunction, including disorientation, confusion, dizziness, erratic behavior, irritability, headache, loss of coordination, delirium, collapse, or seizures.^7,12,15 EHS may also present with symptoms of heat exhaustion, including fatigue, hyperventilation, tachycardia, vomiting, diarrhea, and hypotension.^7,12,15

Rectal temperature should be taken for any athlete with suspected EHS, as other modalities—oral, skin, axillary, and aural—can be inaccurate and easily modified by ambient confounders such as ambient and skin temperature, athlete hyperventilation, and consumption of liquids.^7,11,12 Athletes exhibiting CNS symptoms with moderately elevated rectal temperatures that do not exceed 40°C should also be assumed to be suffering from EHS and treated with rapid cooling.¹¹ On the other hand, athletes with CNS symptoms who are normothermic should be assumed to have EAH until ruled out by electrolyte assessment; IV fluids should be at no more than keep vein open (KVO) pending this determination.¹¹ In some cases, an athlete may initially present with altered mental status but return to “normal.” However, this improvement may represent a “lucid period”; evaluation should continue with rectal temperature and treatment, as EHS in these cases may progress quickly.¹⁵

Treatment is centered on rapid, whole body cooling initiated at the first sign of heat illness.^7,22 The goal of treatment is to achieve a rectal temperature <38.9°C within 30 minutes of the onset of EHS.¹⁵ Upon diagnosis, the athlete should be quickly placed in a tub of ice water to facilitate cold water immersion (CWI) therapy. Some guidelines suggest the athlete’s clothing be removed to potentiate evaporative cooling during CWI;¹² however, cooling should not be delayed due to difficulties in removing equipment. CWI, where a heat stroke victim is submerged in ice water up to their neck while water is continuously circulated, is generally considered to be the gold standard treatment as it is the modality with the highest recorded cooling rates and the lowest rate of morbidity and mortality.^7,20,21 Multiple studies of CWI have shown that survival nears 100% when aggressive cooling starts within 5 minutes of collapse or identification of EHS.^20,21,22

If whole body CWI is unavailable, alternative methods of rapid cooling should be employed. Partial CWI, with torso immersion being preferable to the extremities, has been shown to achieve an acceptable rate of cooling to achieve sufficient drops in internal body temperature.^20,23 However, one popular treatment—applying ice packs to the whole body, in particular to the groin and axillae—has not been shown to be sufficient to achieve standard cooling goals.²⁰ None of these methods have been shown to be as effective as CWI.²³

Intravenous access should be initiated with fluid resuscitation dictated by the provider’s assessment. Normal saline is recommended as the resuscitative fluid of choice, with the rate dictated by clinical judgment and adjusted as guided by electrolyte determination and clinical response. It cannot be overstated that in normothermic patients with confusion, EAH is the diagnosis of exclusion and aggressive fluid resuscitation should be withheld until electrolyte determination.

Once rectal temperature descends appropriately (~38.9°C), the cooling process should stop and the individual should be transported to a hospital for further observation²⁰ and evaluation of possible sequelae, including rhabdomyolysis and renal injury, cardiac dysfunction and arrhythmia, severe electrolyte abnormalities, acute respiratory distress syndrome, lactic acidosis, and other forms of end-organ failure (Figure).

Emergency Action Plan

Team physicians should be proactive in developing an emergency action plan to address possible EHS events. These plans should be site-specific, addressing procedures for all practice and home competition locations.¹² All competition venues should have a CWI tub on-site in events where there is an increased risk of EHS.^12,15,20 This tub should be set up and functional for all high-risk activities, including practices.¹²

Following recognition of a potential case of EHS, treatment teams should have procedures in place to transport athletes to the treatment area, obtain rectal temperature, initiate rapid cooling, and stabilize the athlete for transport to an emergency department (ED) for further evaluation.^12,15 A written record of treatments and medications provided during athlete stabilization should be maintained and transported with the athlete to the ED.¹⁵ A list of helpful equipment and supplies for treatment of EHS can be found in Table 5.

Return to Play

Perhaps the most challenging and important role the team physician has is determining an athlete’s return to play following EHI, as there currently are no evidence-based guidelines for return to activity for these athletes.⁷ The decisions surrounding return to play are highly individualized, as recovery from EHS and heat injury is associated with the duration of internal body temperature elevation above the critical level (40°C).^7,20 Guidelines for return to activity following recovery from EHI differ among experts and institutions.^7,25 The general consensus from these guidelines is that, at minimum, athletes should not participate in any physical activity until they are asymptomatic and all blood tests have normalized.¹¹ Following this asymptomatic period, most guidelines advocate for a slow, deliberate return to activity.¹¹ The American College of Sports Medicine (ACSM) offers one reasonable approach to the returning athlete following EHS:⁷

• No exercise for at least 7 days following release from medical care.
• Follow-up with a physician 1 week after release from medical care for physical examination and any warranted lab or radiologic studies (based upon organ systems affected during EHS).
• Once cleared to return to activity, the athlete begins exercise in a cool environment, gradually increasing the duration, intensity, and heat exposure over 2 weeks to demonstrate heat tolerance and acclimatization.
• Athletes who cannot resume vigorous activity due to recurrent symptoms (eg, excessive fatigue) should be reevaluated after 4 weeks. Laboratory exercise-heat tolerance testing may be useful in this setting.
• The athlete may resume full competition once they are able to participate in full training in the heat for 2 to 4 weeks without adverse effects.

Heat tolerance testing (HTT) in these athletes remains controversial.^{5 26} The ACSM recommends that HTT be considered only for those unable to return to vigorous activity after a suitable period (approximately 4 weeks). In contrast, the Israeli Defense Force (IDF) uses HTT to evaluate soldiers following EHS to guide decision-making about return to duty.²⁷ The IDF HTT assumes that individuals will respond differently to heat stresses. They identify individuals who are “heat intolerant” as being unable to tolerate specific heat challenges, indicated by increases in body temperature occurring more rapidly than normal responders under identical environmental and exercise conditions. However, despite being used for more than 30 years, there is no clear evidence that HTT adequately predicts who will experience subsequent episodes of EHS.

Conclusion

While the recognized cornerstone of being a team physician is the provision of medical care, the ACSM Team Physician Consensus Statement²⁸ further delineates the medical and administrative responsibilities as both (1) understanding medical management and prevention of injury and illness in athletes; and (2) awareness of or involvement in the development and rehearsal of an emergency action plan. These tenets are critical for the team physician who accepts the responsibility to cover sports at the high school level or higher. Football team physicians play an essential role in mitigating risk of EHI in their athletes. Through development and execution of both comprehensive prevention strategies and emergency action plans, physicians can work to minimize athletes’ risk of both developing and experiencing significant adverse outcomes from an EHI.

Am J Orthop. 2016;45(6):340-348. Copyright Frontline Medical Communications Inc. 2016. All rights reserved.

In December 2015, alectinib became the third ALK inhibitor approved by the United States Food and Drug Administration for the treatment of non-small-cell lung cancer (NSCLC) that displays rearrangements of the anaplastic lymphoma kinase (ALK) gene. Alectinib is a second-generation small molecule inhibitor of the ALK protein that joins ceritinib in providing a useful treatment option for patients who have progressed on crizotinib, as a result of its ability to target crizotinib-resistant mutant forms of the ALK protein. Alectinib also displays enhanced penetrance of the blood-brain barrier, which improves efficacy against central nervous system (CNS) metastases.

Click on the PDF icon at the top of this introduction to read the full article.

In December 2015, alectinib became the third ALK inhibitor approved by the United States Food and Drug Administration for the treatment of non-small-cell lung cancer (NSCLC) that displays rearrangements of the anaplastic lymphoma kinase (ALK) gene. Alectinib is a second-generation small molecule inhibitor of the ALK protein that joins ceritinib in providing a useful treatment option for patients who have progressed on crizotinib, as a result of its ability to target crizotinib-resistant mutant forms of the ALK protein. Alectinib also displays enhanced penetrance of the blood-brain barrier, which improves efficacy against central nervous system (CNS) metastases.

Click on the PDF icon at the top of this introduction to read the full article.

In December 2015, alectinib became the third ALK inhibitor approved by the United States Food and Drug Administration for the treatment of non-small-cell lung cancer (NSCLC) that displays rearrangements of the anaplastic lymphoma kinase (ALK) gene. Alectinib is a second-generation small molecule inhibitor of the ALK protein that joins ceritinib in providing a useful treatment option for patients who have progressed on crizotinib, as a result of its ability to target crizotinib-resistant mutant forms of the ALK protein. Alectinib also displays enhanced penetrance of the blood-brain barrier, which improves efficacy against central nervous system (CNS) metastases.

Click on the PDF icon at the top of this introduction to read the full article.

The pace of drug development for multiple myeloma was dizzying in 2015, with 5 regulatory approvals for the treatment of relapsed/refractory disease, 3 in a single month. As we stand on the brink of another paradigm shift in the management of this disease, we discuss the new classes of drugs and how they are shaping standard of care with the potential to make multiple myeloma a chronic disease.

Click on the PDF icon at the top of this introduction to read the full article.

The pace of drug development for multiple myeloma was dizzying in 2015, with 5 regulatory approvals for the treatment of relapsed/refractory disease, 3 in a single month. As we stand on the brink of another paradigm shift in the management of this disease, we discuss the new classes of drugs and how they are shaping standard of care with the potential to make multiple myeloma a chronic disease.

Click on the PDF icon at the top of this introduction to read the full article.

The pace of drug development for multiple myeloma was dizzying in 2015, with 5 regulatory approvals for the treatment of relapsed/refractory disease, 3 in a single month. As we stand on the brink of another paradigm shift in the management of this disease, we discuss the new classes of drugs and how they are shaping standard of care with the potential to make multiple myeloma a chronic disease.

Click on the PDF icon at the top of this introduction to read the full article.

From the MetroHealth System, Cleveland, OH.

Abstract

• Objective: To describe risk factors for unplanned extubation (UE) among critically ill adults requiring mechanical ventilation and to identify strategies to reduce the occurrence of this adverse event.
• Methods: Review of the literature.
• Results: Inadvertent removal of an endotracheal tube, or a UE, occurs in 7% to 22.5% of mechanically ventilated adult patients and is often due to deliberate patient removal. Despite the multitude of research examining risk factors and predictors of UE, rates have remained unchanged for the past 2 decades. Risk factors can be classified by intensive care unit (ICU) type, including medical ICUs, surgical ICUs, and mixed medical-surgical ICUs. The majority of risk factors for UEs across ICUs may be amenable to changes in unit processes, such as programs for agitation management, use of weaning protocols, increased surveillance of patients, and ongoing education for patients and health care staff.
• Conclusion: Prevention of UE remains an elusive target. Changes in unit processes that target identified risk factors may be an effective method to decrease prevalence of UE.

Unplanned extubation (UE) is the inadvertent removal of an endotracheal tube, either by a patient (deliberate self-extubation), or by a member of the health care team providing routine care such as repositioning, suctioning, or procedures (accidental extubation). Approximately 7% to 22.5% of mechanically ventilated patients in the intensive care unit (ICU) experience UE [1–7]. Estimates are likely higher, as current regulatory and accreditation standards do not include mandatory reporting of this event. Despite numerous studies investigating risk factors associated with UE, it remains a prevalent problem with adverse outcomes for patients and hospitals. The purpose of this review is to provide a summary of the literature on risk factors for UE, review effects on patient and organizational outcomes, and identify evidence-based strategies for reducing occurrence of UE among mechanically ventilated patients.

Prevalence of Unplanned Exubation

There is substantial heterogeneity in how UE is calculated and reported in the research literature. UE is calculated as the number of UE events per 100 or 1000 patient days, or the number of UE per total ventilator days. Rates of UE are also reported as the proportion of patients who experience UE out of all intubated patients over a set time period [8]. Despite efforts aimed at mitigating risk factors for UE, rates have remained static over the past 2 decades. Reported UE rates from 1994–2002 were 2.6% to 14% [3,6,9–11], while rates from 2004–2014 ranged from 1% to 22% [3–5,8,12–15]. Interventions utilizing a multidisciplinary approach have been implemented with the aim of decreasing UE, yet few have proven successful on improving rates nationally.

Unplanned self-extubation by the patient (deliberate self-extubation) is the most common type of UE [3,10,12,16–18]. A multicenter trial of 426 patients from 11 medical centers indicates that 46 patients experienced UE, with 36 of these (78.2%) caused by patient self-extubation [6]. Prospective single-site studies report similar or higher estimates of patient self-extubation, ranging from 75.8% to 91.7% [3,5], while a multisite study of 10,112 patients revealed 32 of 35 UE (91.4%) were due to patient self-extubation [12]. Similarly, a 4-year analysis of 85 UEs reported 82 incidences (96.5%) were a result of deliberate patient removal [13]. Patients either physically pull out the endotracheal tube or use their tongue or coughing/gagging maneuvers to displace or intentionally remove the endotracheal tube [5]. Only 3% to 8% of UEs are caused by inadvertent removal by health care staff [3,5,12,13].

Effects on Patient and Organizational Outcomes

Regardless of the cause of the UE, there are adverse consequences for both patients and hospitals. Some patients who experience UE have higher rates of in-hospital mortality; however, this is often due to contributing factors associated with severity of injury, the need for reintubation, and underlying chronic diseases [13]. Patients who experience accidental UE have higher incidence of nosocomial pneumonia (27.6% vs. 138%, P = 0.002) [11], longer duration of mechanical ventilation, and increased length of stay (LOS) [7,13]. While some studies report UE can result in serious consequences such as respiratory distress, hypoxia [13], and even death [6,12], others report lower mortality and length of stay when UE occurs, likely due to the fact that many patients are ready for liberation from mechanical ventilation at the time of UE [5,15].

Despite the emergent nature of UE, not all patients experience immediate reintubation. Many instances of UE occur during patient weaning trials or in preparation for planned extubations [5,11], which explains why only 10% to 60% of patients require reintubation [3,5,10,11,15,19,20]. When reintubation is necessary, it results in increased number of ventilator days [10,11], and increased ICU and hospital LOS [1,11]. There is little evidence directly linking reintubation with in-hospital mortality; however, it can cause serious complications such as hypotension, hypertension, arrhythmias, and airway trauma [21]. For hospitals and health care organizations, the need for reintubation results in increased hospital costs, estimated to be $1000 per reintubation event [17,22]. This estimate does not take into account additional costs incurred with increased ICU care, longer periods of mechanical ventilation, and increased LOS. Estimates of these additional costs in pediatric patients are approximately $36,000 [23]. Costs are likely higher in adult patients, due to multiple comorbidities that often accompany the need for mechanical ventilation, as well as increased pharmacy, lab, and diagnostic charges [1].

Risk Factors for Unplanned Extubation

Medical ICU Risk Factors

MICUs traditionally have the highest rates of UE [4,8]. Data from a national prevalence study indicated that there were 23.4 episodes of UE in MICUs per 1000 ventilator days [4]. Approximately 9.5% to 15% of all ventilated patients in the MICU experience UE [4,5,8]. Patients in the MICU who require mechanical ventilation often have complex chronic illness with underlying respiratory disease, which can result in prolonged periods of ventilation and increased risk of UE. Specific risk factors investigated in UE research include patient specific factors (age, gender, diagnosis, comorbidities, agitation, level of consciousness, laboratory values), ventilatory factors (ventilator type and setting, type of tracheal tube, method of tube fixation), as well as type of sedation and use of protocols [5,6,24]. Surprisingly, few variables emerge as significant risk factors for UE among MICU patients. Risk factors associated with UE have included male gender [24], presence of chronic obstructive pulmonary disease (COPD) [24], increased level of consciousness [25], and use of weaning protocols [5]. While gender, COPD, and level of consciousness increase risk of UE, the presence of weaning protocols is shown to decrease risk of UE [5]. Although UE are reported most often in MICUs, few risk factors consistently emerge for this specific cohort, making definitive recommendations for prevention of UE difficult.

Surgical ICU Risk Factors

The prevalence of UE for mechanically ventilated patients in the SICU tend to be lower than those for MICU cohorts. Prevalence of UE in the SICU is reported at 1.41 episodes per 100 ventilator days [13], or 6.8 episodes per 1000 ventilator days [4]. Percentages of UE in the SICU range from 2% to 6% [4,8,19]. Similar to MICU patients, critically ill patients in the SICU often have specific risk factors placing them at risk for UE. Causative factors examined in research studies with this population include gender, age, sedation scale scores, need for reintubation, time from intubation to extubation, use of sedatives/analgesics, restraints, ICU nurse experience, location of staff at time of UE, and criteria for extubation [17,19]. Similar to MICU cohorts, few variables are identified as predictors of UE. Significant predictors include use of restraints, decreased sedation [17], and meeting criteria for extubation [19]. Among patients who experienced an UE, 87% were restrained at the time of the UE [17], and most had low levels of sedation (mean Ramsay sedation scale score = 2.42 in the hour preceding the UE). Approximately 64% of patients who experienced UE met criteria for planned extubation and did not require re-intubation [19], suggesting many patients were essentially ready for planned extubation.

Mixed ICU Risk Factors

The majority of research investigating risk factors for UE is conducted within medical-surgical or mixed/general ICUs. The prevalence of UE within this type of unit is reported at 1.59 episodes per 100 patient days [6], or approximately 2% to 10% [4,6,7]. Among this population, potential risk factors are similar to those included in solely MICU or SICU studies. Because of the high number of studies investigating UE in a mixed ICU setting, there are significantly more variables included in as potential risk factors. Variables include patient age, gender, admission diagnosis, injury severity using Acute Physiological and Chronic Health Evaluation (APACHE II), ICU and hospital LOS, patient level of consciousness, agitation, days of mechanical ventilation, ventilator settings, nosocomial infection, sedation, physical restraints, vital signs [7,14,26], laboratory values, medication types, and body mass index [15,26]. One study also included time of UE and ICU nurse level of experience [3]. Among all factors, several were significant predictors of UE: male gender [15], decreased sedation and increased level of consciousness [8], agitation [3,19,26], use of restraints [3,7], sedation practices (particularly use of benzodiazapines) [3,7,15,26,27], lack of strong tube fixation, absence of IV sedation, and orotracheal intubation [6]. UE were more likely to occur on the night shift and among staff that included nurses with fewer years of experience [3]. Many episodes of UE occurred during weaning [10] or among patients who could communicate and were alert [3]. One study reports 57% of patients who intentionally self-extubated explained they simply removed the tube because it was uncomfortable [3].

Strategies for Reducing Adverse Events

Agitation Management

The majority of studies cited agitation, altered level of consciousness, or inadequate sedation as risk factors for UE [3,6–8,15,17,18,25,26,28,29]. These factors directly impact restraint use, another common risk factor for UE [3,7,17]. A key recommendation for agitation management is to identify the source of agitation, which is often caused by delirium onset in the ICU [30–32]. Prevalence of delirium in the ICU ranges from 20% to 80% [33–35]. ICU patients are at high risk for delirium due to sleep deprivation, older age, restraints, abnormal lab values, medications, infection, and respiratory complications [31]. Treatment for delirium centers on prevention, early recognition, interdisciplinary and pharmacologic protocols, increased nursing presence, and use of short-acting sedation when necessary [30–32,36]. While there is no research specifically linking delirium to UE, a quality analysis of risk factors present at the time of UE using bow-tie analysis methods identified delirium as a key factor present in the majority of UE cases [36]. It is possible that agitation reported in other studies investigating risk factors for UE may actually be reflective of underlying delirium. Routine screening using validated tools, such as the Confusion Assessment Method-ICU (CAM-ICU) [37] would aid in early detection and management of delirium, and would provide a standardized method for exploring the relationship of delirium and UE in future trials.

Integration of Weaning Protocols

Protocol-directed weaning is beneficial for decreasing ventilator days, time to wean from mechanical ventilation, and ICU LOS [38]. A systematic review including 7 trials (2434 patients) comparing protocol/non-protocol for weaning from mechanical ventilation reported a 26% decrease in the mean duration of mechanical ventilation for the protocol groups (95% CI 13%–37%, P < 0.001), a 70% reduction in time to wean, (95% CI 27%–88%, P = 0.009), and a decrease in ICU LOS by 11% (95% CI 3%–19%, P = 0.01). Weaning protocols are also an important risk factor for UE [5]. Findings from a prospective cohort study specifically identify the presence of weaning protocols as an important factor for reducing UE; patients who had weaning protocols ordered and followed were least likely to experience UE (P = 0.02) [5]. A separate quality improvement initiative demonstrated an overall decrease in the number of UEs (from 5.2% to 0.9%) after implementing weaning protocols as standard of care [39]. Considering many UEs occur during weaning [10], integration of weaning protocols aids in expediting the process and ensuring timely extubation.

Increased Surveillance

Increasing surveillance and monitoring of ventilated patients is a recommendation based on risk factors presented at the time of UE. Specifically, staffing levels and shifts and the use of physical restraints are variables associated with UE that are amendable to changes in unit processes based on increased surveillance. It is reported that 40% to 76% of UEs occurred during the night shift [14,17,24,40]; many more occur during change of shift or when there is not a nurse present at the bedside [3,17]. Recent trends towards mandatory bedside reporting is a specific intervention that may positively impact UE among patients in the ICU [41]. Meta-analyses of observational studies investigating the effect of nurse staffing on hospital outcomes indicate that increasing the number of RNs is associated with decreased risk of adverse patient outcomes, including UE [42,43]. The addition of 1 additional nurse per patient day can result in a 51% decrease in UE, while a decrease in nursing workload could result in a 45% decrease in UE [42]. Data from a national prevalence study reports ICUs with fewer available resources, including staff, experienced a higher number of UEs [4].

Increasing surveillance by nursing and health care staff may also impact prevalence of physical restraint use. A significant number of patients who experience UE are physically restrained at the time of the incident, ranging from 40% to 90% of intubated patients [5–7,14,17,40]. It is well documented that UE continue to occur despite the use of restraints [5,7,28,29,44] Patients who are physically restrained often experience higher rates of unplanned extubation (42.9% vs. 16.5% , P < 0.001 in Chang et al’s study [7]), and longer ICU LOS (20.3 days vs. 15.8 days, P = 0.009) [7]. Soft wrist restraints are commonly used to prevent pulling of the endotracheal tube; however, research evidence on UE demonstrates this is not always an effective intervention. Increasing surveillance of ventilated patients, treating their agitation and screening for underlying delirium, and integration of weaning protocols are all interventions that may decrease UE and the need for routine use of physical restraints.

Ongoing Education for Patients and Health Care Staff

Initial and ongoing education about UE, risk factors, and effective interventions is beneficial for patients and health care staff. Although there are no trials investigating effects of educational interventions for patients on UE outcomes, pre-education of surgical patients regarding what to expect while intubated may aid in decreasing delirium risk, agitation, physical restraint use, and possibly UE. Verbal and written educational information during pre-admission testing is a feasible method easily integrated into pre-operative programs.

Because UEs often occur more frequently among less experienced staff, initial education about risk factors for UE is crucial to include in ICU staff orientation programs [3,7]. Educational initiatives should incorporate training on routine delirium screening and avoidance of agitation, use of protocols, and increased surveillance of patients receiving mechanical ventilation [5,15,17,39,45]. Ongoing education of staff regarding ventilatory equipment and risk factors for UE can be particularly effective in decreasing UE [46]. Initial educational efforts should be followed by routine updates for all members of the healthcare team about ongoing quality improvement efforts to monitor UE. Associated factors for UE that may be unit- or process-specific, including methods for endotracheal tube securement and intra-hospital transport, should be communicated with all individuals involved in patient care. Integration of continuous quality improvement programs can decrease UE rates by 22% to 53% [16]. Quality efforts typically focus on standardization of reporting and tracking tools, protocol implementations, and ongoing monitoring, auditing, and recording of UE.

Current Trends and Future Directions

Recent trends in critical care recommendations may mitigate potential risk factors identified in UE research. Integration of lightened sedation and daily wake up periods for intubated patients may decrease prevalence of risk factors for UE, specifically agitation, physical restraint use, and altered level of consciousness [30], while routine weaning protocols may improve ventilatory outcomes, including UE [5,38,40]. Nursing bedside report and purposeful hourly rounding are quickly emerging as mainstays of professional nursing care [41]. Inherent in these 2 initiatives are increased surveillance and vigilance by health care staff, which can result in timely extubation of those who indicate readiness, as well as decreased incidence of adverse events. Delirium remains a key factor that may be a likely cause for UE; recent trends towards early detection and proper management of delirium among ICU staff may result in improved ventilatory outcomes, including weaning, planned extubation, and the prevalence of UE.

Another important trend in critical care is the emergence of a neurocritical care specialty and routine admission of neurocritically ill patients to neuroscience ICUs [47,48]. However, there are no studies investigating prevalence of UE among these patients, who often have higher rates of agitation or restlessness due to cognitive impairment. Among general ICUs, patients with a primary respiratory diagnosis accounted for 23% of all UE in one study, while those with a neurological diagnosis accounted for the second highest percentage (12%) among the study population [15]. A separate study concluded that presence of neurological injury with a concomitant nosocomial infection increased risk of UE among patients in a mixed ICU [7]. A recent systematic review of weaning protocols highlights positive effects on ventilatory outcomes but cites lack of evidence for effectiveness of protocols among those with neurological injury [38]. Areas for future UE research should include factors specific to this patient population, as they may be at higher risk for adverse ventilatory outcomes due to the nature of the neurological injury.

Conclusion

Prevention of UE remains an elusive target, evidenced by little change in reported rates over 2 decades. Research provides data on risk factors that may be patient, unit, or process related. Structuring prevention efforts around modifiable risk factors for UE is a feasible approach amenable to ongoing monitoring for effectiveness. Integration of current trends in health care safety and quality may produce an added benefit of reducing the occurrence of UE in critical care units. Future research evaluating these trends and the prevalence of UE in subspecialty populations is warranted.

Corresponding author: Molly McNett, PhD, RN, CNRN, Attn: NBO, MetroHealth Medical Center, 2500 MetroHealth Drive; Cleveland, OH 44109, mmcnett@metrohealth.org.

Financial disclosures: None.

From the MetroHealth System, Cleveland, OH.

Abstract

• Objective: To describe risk factors for unplanned extubation (UE) among critically ill adults requiring mechanical ventilation and to identify strategies to reduce the occurrence of this adverse event.
• Methods: Review of the literature.
• Results: Inadvertent removal of an endotracheal tube, or a UE, occurs in 7% to 22.5% of mechanically ventilated adult patients and is often due to deliberate patient removal. Despite the multitude of research examining risk factors and predictors of UE, rates have remained unchanged for the past 2 decades. Risk factors can be classified by intensive care unit (ICU) type, including medical ICUs, surgical ICUs, and mixed medical-surgical ICUs. The majority of risk factors for UEs across ICUs may be amenable to changes in unit processes, such as programs for agitation management, use of weaning protocols, increased surveillance of patients, and ongoing education for patients and health care staff.
• Conclusion: Prevention of UE remains an elusive target. Changes in unit processes that target identified risk factors may be an effective method to decrease prevalence of UE.

Unplanned extubation (UE) is the inadvertent removal of an endotracheal tube, either by a patient (deliberate self-extubation), or by a member of the health care team providing routine care such as repositioning, suctioning, or procedures (accidental extubation). Approximately 7% to 22.5% of mechanically ventilated patients in the intensive care unit (ICU) experience UE [1–7]. Estimates are likely higher, as current regulatory and accreditation standards do not include mandatory reporting of this event. Despite numerous studies investigating risk factors associated with UE, it remains a prevalent problem with adverse outcomes for patients and hospitals. The purpose of this review is to provide a summary of the literature on risk factors for UE, review effects on patient and organizational outcomes, and identify evidence-based strategies for reducing occurrence of UE among mechanically ventilated patients.

Prevalence of Unplanned Exubation

There is substantial heterogeneity in how UE is calculated and reported in the research literature. UE is calculated as the number of UE events per 100 or 1000 patient days, or the number of UE per total ventilator days. Rates of UE are also reported as the proportion of patients who experience UE out of all intubated patients over a set time period [8]. Despite efforts aimed at mitigating risk factors for UE, rates have remained static over the past 2 decades. Reported UE rates from 1994–2002 were 2.6% to 14% [3,6,9–11], while rates from 2004–2014 ranged from 1% to 22% [3–5,8,12–15]. Interventions utilizing a multidisciplinary approach have been implemented with the aim of decreasing UE, yet few have proven successful on improving rates nationally.

Unplanned self-extubation by the patient (deliberate self-extubation) is the most common type of UE [3,10,12,16–18]. A multicenter trial of 426 patients from 11 medical centers indicates that 46 patients experienced UE, with 36 of these (78.2%) caused by patient self-extubation [6]. Prospective single-site studies report similar or higher estimates of patient self-extubation, ranging from 75.8% to 91.7% [3,5], while a multisite study of 10,112 patients revealed 32 of 35 UE (91.4%) were due to patient self-extubation [12]. Similarly, a 4-year analysis of 85 UEs reported 82 incidences (96.5%) were a result of deliberate patient removal [13]. Patients either physically pull out the endotracheal tube or use their tongue or coughing/gagging maneuvers to displace or intentionally remove the endotracheal tube [5]. Only 3% to 8% of UEs are caused by inadvertent removal by health care staff [3,5,12,13].

Effects on Patient and Organizational Outcomes

Regardless of the cause of the UE, there are adverse consequences for both patients and hospitals. Some patients who experience UE have higher rates of in-hospital mortality; however, this is often due to contributing factors associated with severity of injury, the need for reintubation, and underlying chronic diseases [13]. Patients who experience accidental UE have higher incidence of nosocomial pneumonia (27.6% vs. 138%, P = 0.002) [11], longer duration of mechanical ventilation, and increased length of stay (LOS) [7,13]. While some studies report UE can result in serious consequences such as respiratory distress, hypoxia [13], and even death [6,12], others report lower mortality and length of stay when UE occurs, likely due to the fact that many patients are ready for liberation from mechanical ventilation at the time of UE [5,15].

Despite the emergent nature of UE, not all patients experience immediate reintubation. Many instances of UE occur during patient weaning trials or in preparation for planned extubations [5,11], which explains why only 10% to 60% of patients require reintubation [3,5,10,11,15,19,20]. When reintubation is necessary, it results in increased number of ventilator days [10,11], and increased ICU and hospital LOS [1,11]. There is little evidence directly linking reintubation with in-hospital mortality; however, it can cause serious complications such as hypotension, hypertension, arrhythmias, and airway trauma [21]. For hospitals and health care organizations, the need for reintubation results in increased hospital costs, estimated to be $1000 per reintubation event [17,22]. This estimate does not take into account additional costs incurred with increased ICU care, longer periods of mechanical ventilation, and increased LOS. Estimates of these additional costs in pediatric patients are approximately $36,000 [23]. Costs are likely higher in adult patients, due to multiple comorbidities that often accompany the need for mechanical ventilation, as well as increased pharmacy, lab, and diagnostic charges [1].

Risk Factors for Unplanned Extubation

Medical ICU Risk Factors

MICUs traditionally have the highest rates of UE [4,8]. Data from a national prevalence study indicated that there were 23.4 episodes of UE in MICUs per 1000 ventilator days [4]. Approximately 9.5% to 15% of all ventilated patients in the MICU experience UE [4,5,8]. Patients in the MICU who require mechanical ventilation often have complex chronic illness with underlying respiratory disease, which can result in prolonged periods of ventilation and increased risk of UE. Specific risk factors investigated in UE research include patient specific factors (age, gender, diagnosis, comorbidities, agitation, level of consciousness, laboratory values), ventilatory factors (ventilator type and setting, type of tracheal tube, method of tube fixation), as well as type of sedation and use of protocols [5,6,24]. Surprisingly, few variables emerge as significant risk factors for UE among MICU patients. Risk factors associated with UE have included male gender [24], presence of chronic obstructive pulmonary disease (COPD) [24], increased level of consciousness [25], and use of weaning protocols [5]. While gender, COPD, and level of consciousness increase risk of UE, the presence of weaning protocols is shown to decrease risk of UE [5]. Although UE are reported most often in MICUs, few risk factors consistently emerge for this specific cohort, making definitive recommendations for prevention of UE difficult.

Surgical ICU Risk Factors

The prevalence of UE for mechanically ventilated patients in the SICU tend to be lower than those for MICU cohorts. Prevalence of UE in the SICU is reported at 1.41 episodes per 100 ventilator days [13], or 6.8 episodes per 1000 ventilator days [4]. Percentages of UE in the SICU range from 2% to 6% [4,8,19]. Similar to MICU patients, critically ill patients in the SICU often have specific risk factors placing them at risk for UE. Causative factors examined in research studies with this population include gender, age, sedation scale scores, need for reintubation, time from intubation to extubation, use of sedatives/analgesics, restraints, ICU nurse experience, location of staff at time of UE, and criteria for extubation [17,19]. Similar to MICU cohorts, few variables are identified as predictors of UE. Significant predictors include use of restraints, decreased sedation [17], and meeting criteria for extubation [19]. Among patients who experienced an UE, 87% were restrained at the time of the UE [17], and most had low levels of sedation (mean Ramsay sedation scale score = 2.42 in the hour preceding the UE). Approximately 64% of patients who experienced UE met criteria for planned extubation and did not require re-intubation [19], suggesting many patients were essentially ready for planned extubation.

Mixed ICU Risk Factors

The majority of research investigating risk factors for UE is conducted within medical-surgical or mixed/general ICUs. The prevalence of UE within this type of unit is reported at 1.59 episodes per 100 patient days [6], or approximately 2% to 10% [4,6,7]. Among this population, potential risk factors are similar to those included in solely MICU or SICU studies. Because of the high number of studies investigating UE in a mixed ICU setting, there are significantly more variables included in as potential risk factors. Variables include patient age, gender, admission diagnosis, injury severity using Acute Physiological and Chronic Health Evaluation (APACHE II), ICU and hospital LOS, patient level of consciousness, agitation, days of mechanical ventilation, ventilator settings, nosocomial infection, sedation, physical restraints, vital signs [7,14,26], laboratory values, medication types, and body mass index [15,26]. One study also included time of UE and ICU nurse level of experience [3]. Among all factors, several were significant predictors of UE: male gender [15], decreased sedation and increased level of consciousness [8], agitation [3,19,26], use of restraints [3,7], sedation practices (particularly use of benzodiazapines) [3,7,15,26,27], lack of strong tube fixation, absence of IV sedation, and orotracheal intubation [6]. UE were more likely to occur on the night shift and among staff that included nurses with fewer years of experience [3]. Many episodes of UE occurred during weaning [10] or among patients who could communicate and were alert [3]. One study reports 57% of patients who intentionally self-extubated explained they simply removed the tube because it was uncomfortable [3].

Strategies for Reducing Adverse Events

Agitation Management

The majority of studies cited agitation, altered level of consciousness, or inadequate sedation as risk factors for UE [3,6–8,15,17,18,25,26,28,29]. These factors directly impact restraint use, another common risk factor for UE [3,7,17]. A key recommendation for agitation management is to identify the source of agitation, which is often caused by delirium onset in the ICU [30–32]. Prevalence of delirium in the ICU ranges from 20% to 80% [33–35]. ICU patients are at high risk for delirium due to sleep deprivation, older age, restraints, abnormal lab values, medications, infection, and respiratory complications [31]. Treatment for delirium centers on prevention, early recognition, interdisciplinary and pharmacologic protocols, increased nursing presence, and use of short-acting sedation when necessary [30–32,36]. While there is no research specifically linking delirium to UE, a quality analysis of risk factors present at the time of UE using bow-tie analysis methods identified delirium as a key factor present in the majority of UE cases [36]. It is possible that agitation reported in other studies investigating risk factors for UE may actually be reflective of underlying delirium. Routine screening using validated tools, such as the Confusion Assessment Method-ICU (CAM-ICU) [37] would aid in early detection and management of delirium, and would provide a standardized method for exploring the relationship of delirium and UE in future trials.

Integration of Weaning Protocols

Protocol-directed weaning is beneficial for decreasing ventilator days, time to wean from mechanical ventilation, and ICU LOS [38]. A systematic review including 7 trials (2434 patients) comparing protocol/non-protocol for weaning from mechanical ventilation reported a 26% decrease in the mean duration of mechanical ventilation for the protocol groups (95% CI 13%–37%, P < 0.001), a 70% reduction in time to wean, (95% CI 27%–88%, P = 0.009), and a decrease in ICU LOS by 11% (95% CI 3%–19%, P = 0.01). Weaning protocols are also an important risk factor for UE [5]. Findings from a prospective cohort study specifically identify the presence of weaning protocols as an important factor for reducing UE; patients who had weaning protocols ordered and followed were least likely to experience UE (P = 0.02) [5]. A separate quality improvement initiative demonstrated an overall decrease in the number of UEs (from 5.2% to 0.9%) after implementing weaning protocols as standard of care [39]. Considering many UEs occur during weaning [10], integration of weaning protocols aids in expediting the process and ensuring timely extubation.

Increased Surveillance

Increasing surveillance and monitoring of ventilated patients is a recommendation based on risk factors presented at the time of UE. Specifically, staffing levels and shifts and the use of physical restraints are variables associated with UE that are amendable to changes in unit processes based on increased surveillance. It is reported that 40% to 76% of UEs occurred during the night shift [14,17,24,40]; many more occur during change of shift or when there is not a nurse present at the bedside [3,17]. Recent trends towards mandatory bedside reporting is a specific intervention that may positively impact UE among patients in the ICU [41]. Meta-analyses of observational studies investigating the effect of nurse staffing on hospital outcomes indicate that increasing the number of RNs is associated with decreased risk of adverse patient outcomes, including UE [42,43]. The addition of 1 additional nurse per patient day can result in a 51% decrease in UE, while a decrease in nursing workload could result in a 45% decrease in UE [42]. Data from a national prevalence study reports ICUs with fewer available resources, including staff, experienced a higher number of UEs [4].

Increasing surveillance by nursing and health care staff may also impact prevalence of physical restraint use. A significant number of patients who experience UE are physically restrained at the time of the incident, ranging from 40% to 90% of intubated patients [5–7,14,17,40]. It is well documented that UE continue to occur despite the use of restraints [5,7,28,29,44] Patients who are physically restrained often experience higher rates of unplanned extubation (42.9% vs. 16.5% , P < 0.001 in Chang et al’s study [7]), and longer ICU LOS (20.3 days vs. 15.8 days, P = 0.009) [7]. Soft wrist restraints are commonly used to prevent pulling of the endotracheal tube; however, research evidence on UE demonstrates this is not always an effective intervention. Increasing surveillance of ventilated patients, treating their agitation and screening for underlying delirium, and integration of weaning protocols are all interventions that may decrease UE and the need for routine use of physical restraints.

Ongoing Education for Patients and Health Care Staff

Initial and ongoing education about UE, risk factors, and effective interventions is beneficial for patients and health care staff. Although there are no trials investigating effects of educational interventions for patients on UE outcomes, pre-education of surgical patients regarding what to expect while intubated may aid in decreasing delirium risk, agitation, physical restraint use, and possibly UE. Verbal and written educational information during pre-admission testing is a feasible method easily integrated into pre-operative programs.

Because UEs often occur more frequently among less experienced staff, initial education about risk factors for UE is crucial to include in ICU staff orientation programs [3,7]. Educational initiatives should incorporate training on routine delirium screening and avoidance of agitation, use of protocols, and increased surveillance of patients receiving mechanical ventilation [5,15,17,39,45]. Ongoing education of staff regarding ventilatory equipment and risk factors for UE can be particularly effective in decreasing UE [46]. Initial educational efforts should be followed by routine updates for all members of the healthcare team about ongoing quality improvement efforts to monitor UE. Associated factors for UE that may be unit- or process-specific, including methods for endotracheal tube securement and intra-hospital transport, should be communicated with all individuals involved in patient care. Integration of continuous quality improvement programs can decrease UE rates by 22% to 53% [16]. Quality efforts typically focus on standardization of reporting and tracking tools, protocol implementations, and ongoing monitoring, auditing, and recording of UE.

Current Trends and Future Directions

Recent trends in critical care recommendations may mitigate potential risk factors identified in UE research. Integration of lightened sedation and daily wake up periods for intubated patients may decrease prevalence of risk factors for UE, specifically agitation, physical restraint use, and altered level of consciousness [30], while routine weaning protocols may improve ventilatory outcomes, including UE [5,38,40]. Nursing bedside report and purposeful hourly rounding are quickly emerging as mainstays of professional nursing care [41]. Inherent in these 2 initiatives are increased surveillance and vigilance by health care staff, which can result in timely extubation of those who indicate readiness, as well as decreased incidence of adverse events. Delirium remains a key factor that may be a likely cause for UE; recent trends towards early detection and proper management of delirium among ICU staff may result in improved ventilatory outcomes, including weaning, planned extubation, and the prevalence of UE.

Another important trend in critical care is the emergence of a neurocritical care specialty and routine admission of neurocritically ill patients to neuroscience ICUs [47,48]. However, there are no studies investigating prevalence of UE among these patients, who often have higher rates of agitation or restlessness due to cognitive impairment. Among general ICUs, patients with a primary respiratory diagnosis accounted for 23% of all UE in one study, while those with a neurological diagnosis accounted for the second highest percentage (12%) among the study population [15]. A separate study concluded that presence of neurological injury with a concomitant nosocomial infection increased risk of UE among patients in a mixed ICU [7]. A recent systematic review of weaning protocols highlights positive effects on ventilatory outcomes but cites lack of evidence for effectiveness of protocols among those with neurological injury [38]. Areas for future UE research should include factors specific to this patient population, as they may be at higher risk for adverse ventilatory outcomes due to the nature of the neurological injury.

Conclusion

Prevention of UE remains an elusive target, evidenced by little change in reported rates over 2 decades. Research provides data on risk factors that may be patient, unit, or process related. Structuring prevention efforts around modifiable risk factors for UE is a feasible approach amenable to ongoing monitoring for effectiveness. Integration of current trends in health care safety and quality may produce an added benefit of reducing the occurrence of UE in critical care units. Future research evaluating these trends and the prevalence of UE in subspecialty populations is warranted.

Corresponding author: Molly McNett, PhD, RN, CNRN, Attn: NBO, MetroHealth Medical Center, 2500 MetroHealth Drive; Cleveland, OH 44109, mmcnett@metrohealth.org.

Financial disclosures: None.

From the MetroHealth System, Cleveland, OH.

Abstract

• Objective: To describe risk factors for unplanned extubation (UE) among critically ill adults requiring mechanical ventilation and to identify strategies to reduce the occurrence of this adverse event.
• Methods: Review of the literature.
• Results: Inadvertent removal of an endotracheal tube, or a UE, occurs in 7% to 22.5% of mechanically ventilated adult patients and is often due to deliberate patient removal. Despite the multitude of research examining risk factors and predictors of UE, rates have remained unchanged for the past 2 decades. Risk factors can be classified by intensive care unit (ICU) type, including medical ICUs, surgical ICUs, and mixed medical-surgical ICUs. The majority of risk factors for UEs across ICUs may be amenable to changes in unit processes, such as programs for agitation management, use of weaning protocols, increased surveillance of patients, and ongoing education for patients and health care staff.
• Conclusion: Prevention of UE remains an elusive target. Changes in unit processes that target identified risk factors may be an effective method to decrease prevalence of UE.

Unplanned extubation (UE) is the inadvertent removal of an endotracheal tube, either by a patient (deliberate self-extubation), or by a member of the health care team providing routine care such as repositioning, suctioning, or procedures (accidental extubation). Approximately 7% to 22.5% of mechanically ventilated patients in the intensive care unit (ICU) experience UE [1–7]. Estimates are likely higher, as current regulatory and accreditation standards do not include mandatory reporting of this event. Despite numerous studies investigating risk factors associated with UE, it remains a prevalent problem with adverse outcomes for patients and hospitals. The purpose of this review is to provide a summary of the literature on risk factors for UE, review effects on patient and organizational outcomes, and identify evidence-based strategies for reducing occurrence of UE among mechanically ventilated patients.

Prevalence of Unplanned Exubation

There is substantial heterogeneity in how UE is calculated and reported in the research literature. UE is calculated as the number of UE events per 100 or 1000 patient days, or the number of UE per total ventilator days. Rates of UE are also reported as the proportion of patients who experience UE out of all intubated patients over a set time period [8]. Despite efforts aimed at mitigating risk factors for UE, rates have remained static over the past 2 decades. Reported UE rates from 1994–2002 were 2.6% to 14% [3,6,9–11], while rates from 2004–2014 ranged from 1% to 22% [3–5,8,12–15]. Interventions utilizing a multidisciplinary approach have been implemented with the aim of decreasing UE, yet few have proven successful on improving rates nationally.

Unplanned self-extubation by the patient (deliberate self-extubation) is the most common type of UE [3,10,12,16–18]. A multicenter trial of 426 patients from 11 medical centers indicates that 46 patients experienced UE, with 36 of these (78.2%) caused by patient self-extubation [6]. Prospective single-site studies report similar or higher estimates of patient self-extubation, ranging from 75.8% to 91.7% [3,5], while a multisite study of 10,112 patients revealed 32 of 35 UE (91.4%) were due to patient self-extubation [12]. Similarly, a 4-year analysis of 85 UEs reported 82 incidences (96.5%) were a result of deliberate patient removal [13]. Patients either physically pull out the endotracheal tube or use their tongue or coughing/gagging maneuvers to displace or intentionally remove the endotracheal tube [5]. Only 3% to 8% of UEs are caused by inadvertent removal by health care staff [3,5,12,13].

Effects on Patient and Organizational Outcomes

Regardless of the cause of the UE, there are adverse consequences for both patients and hospitals. Some patients who experience UE have higher rates of in-hospital mortality; however, this is often due to contributing factors associated with severity of injury, the need for reintubation, and underlying chronic diseases [13]. Patients who experience accidental UE have higher incidence of nosocomial pneumonia (27.6% vs. 138%, P = 0.002) [11], longer duration of mechanical ventilation, and increased length of stay (LOS) [7,13]. While some studies report UE can result in serious consequences such as respiratory distress, hypoxia [13], and even death [6,12], others report lower mortality and length of stay when UE occurs, likely due to the fact that many patients are ready for liberation from mechanical ventilation at the time of UE [5,15].

Despite the emergent nature of UE, not all patients experience immediate reintubation. Many instances of UE occur during patient weaning trials or in preparation for planned extubations [5,11], which explains why only 10% to 60% of patients require reintubation [3,5,10,11,15,19,20]. When reintubation is necessary, it results in increased number of ventilator days [10,11], and increased ICU and hospital LOS [1,11]. There is little evidence directly linking reintubation with in-hospital mortality; however, it can cause serious complications such as hypotension, hypertension, arrhythmias, and airway trauma [21]. For hospitals and health care organizations, the need for reintubation results in increased hospital costs, estimated to be $1000 per reintubation event [17,22]. This estimate does not take into account additional costs incurred with increased ICU care, longer periods of mechanical ventilation, and increased LOS. Estimates of these additional costs in pediatric patients are approximately $36,000 [23]. Costs are likely higher in adult patients, due to multiple comorbidities that often accompany the need for mechanical ventilation, as well as increased pharmacy, lab, and diagnostic charges [1].

Risk Factors for Unplanned Extubation

Medical ICU Risk Factors

MICUs traditionally have the highest rates of UE [4,8]. Data from a national prevalence study indicated that there were 23.4 episodes of UE in MICUs per 1000 ventilator days [4]. Approximately 9.5% to 15% of all ventilated patients in the MICU experience UE [4,5,8]. Patients in the MICU who require mechanical ventilation often have complex chronic illness with underlying respiratory disease, which can result in prolonged periods of ventilation and increased risk of UE. Specific risk factors investigated in UE research include patient specific factors (age, gender, diagnosis, comorbidities, agitation, level of consciousness, laboratory values), ventilatory factors (ventilator type and setting, type of tracheal tube, method of tube fixation), as well as type of sedation and use of protocols [5,6,24]. Surprisingly, few variables emerge as significant risk factors for UE among MICU patients. Risk factors associated with UE have included male gender [24], presence of chronic obstructive pulmonary disease (COPD) [24], increased level of consciousness [25], and use of weaning protocols [5]. While gender, COPD, and level of consciousness increase risk of UE, the presence of weaning protocols is shown to decrease risk of UE [5]. Although UE are reported most often in MICUs, few risk factors consistently emerge for this specific cohort, making definitive recommendations for prevention of UE difficult.

Surgical ICU Risk Factors

The prevalence of UE for mechanically ventilated patients in the SICU tend to be lower than those for MICU cohorts. Prevalence of UE in the SICU is reported at 1.41 episodes per 100 ventilator days [13], or 6.8 episodes per 1000 ventilator days [4]. Percentages of UE in the SICU range from 2% to 6% [4,8,19]. Similar to MICU patients, critically ill patients in the SICU often have specific risk factors placing them at risk for UE. Causative factors examined in research studies with this population include gender, age, sedation scale scores, need for reintubation, time from intubation to extubation, use of sedatives/analgesics, restraints, ICU nurse experience, location of staff at time of UE, and criteria for extubation [17,19]. Similar to MICU cohorts, few variables are identified as predictors of UE. Significant predictors include use of restraints, decreased sedation [17], and meeting criteria for extubation [19]. Among patients who experienced an UE, 87% were restrained at the time of the UE [17], and most had low levels of sedation (mean Ramsay sedation scale score = 2.42 in the hour preceding the UE). Approximately 64% of patients who experienced UE met criteria for planned extubation and did not require re-intubation [19], suggesting many patients were essentially ready for planned extubation.

Mixed ICU Risk Factors

The majority of research investigating risk factors for UE is conducted within medical-surgical or mixed/general ICUs. The prevalence of UE within this type of unit is reported at 1.59 episodes per 100 patient days [6], or approximately 2% to 10% [4,6,7]. Among this population, potential risk factors are similar to those included in solely MICU or SICU studies. Because of the high number of studies investigating UE in a mixed ICU setting, there are significantly more variables included in as potential risk factors. Variables include patient age, gender, admission diagnosis, injury severity using Acute Physiological and Chronic Health Evaluation (APACHE II), ICU and hospital LOS, patient level of consciousness, agitation, days of mechanical ventilation, ventilator settings, nosocomial infection, sedation, physical restraints, vital signs [7,14,26], laboratory values, medication types, and body mass index [15,26]. One study also included time of UE and ICU nurse level of experience [3]. Among all factors, several were significant predictors of UE: male gender [15], decreased sedation and increased level of consciousness [8], agitation [3,19,26], use of restraints [3,7], sedation practices (particularly use of benzodiazapines) [3,7,15,26,27], lack of strong tube fixation, absence of IV sedation, and orotracheal intubation [6]. UE were more likely to occur on the night shift and among staff that included nurses with fewer years of experience [3]. Many episodes of UE occurred during weaning [10] or among patients who could communicate and were alert [3]. One study reports 57% of patients who intentionally self-extubated explained they simply removed the tube because it was uncomfortable [3].

Strategies for Reducing Adverse Events

Agitation Management

The majority of studies cited agitation, altered level of consciousness, or inadequate sedation as risk factors for UE [3,6–8,15,17,18,25,26,28,29]. These factors directly impact restraint use, another common risk factor for UE [3,7,17]. A key recommendation for agitation management is to identify the source of agitation, which is often caused by delirium onset in the ICU [30–32]. Prevalence of delirium in the ICU ranges from 20% to 80% [33–35]. ICU patients are at high risk for delirium due to sleep deprivation, older age, restraints, abnormal lab values, medications, infection, and respiratory complications [31]. Treatment for delirium centers on prevention, early recognition, interdisciplinary and pharmacologic protocols, increased nursing presence, and use of short-acting sedation when necessary [30–32,36]. While there is no research specifically linking delirium to UE, a quality analysis of risk factors present at the time of UE using bow-tie analysis methods identified delirium as a key factor present in the majority of UE cases [36]. It is possible that agitation reported in other studies investigating risk factors for UE may actually be reflective of underlying delirium. Routine screening using validated tools, such as the Confusion Assessment Method-ICU (CAM-ICU) [37] would aid in early detection and management of delirium, and would provide a standardized method for exploring the relationship of delirium and UE in future trials.

Integration of Weaning Protocols

Protocol-directed weaning is beneficial for decreasing ventilator days, time to wean from mechanical ventilation, and ICU LOS [38]. A systematic review including 7 trials (2434 patients) comparing protocol/non-protocol for weaning from mechanical ventilation reported a 26% decrease in the mean duration of mechanical ventilation for the protocol groups (95% CI 13%–37%, P < 0.001), a 70% reduction in time to wean, (95% CI 27%–88%, P = 0.009), and a decrease in ICU LOS by 11% (95% CI 3%–19%, P = 0.01). Weaning protocols are also an important risk factor for UE [5]. Findings from a prospective cohort study specifically identify the presence of weaning protocols as an important factor for reducing UE; patients who had weaning protocols ordered and followed were least likely to experience UE (P = 0.02) [5]. A separate quality improvement initiative demonstrated an overall decrease in the number of UEs (from 5.2% to 0.9%) after implementing weaning protocols as standard of care [39]. Considering many UEs occur during weaning [10], integration of weaning protocols aids in expediting the process and ensuring timely extubation.

Increased Surveillance

Increasing surveillance and monitoring of ventilated patients is a recommendation based on risk factors presented at the time of UE. Specifically, staffing levels and shifts and the use of physical restraints are variables associated with UE that are amendable to changes in unit processes based on increased surveillance. It is reported that 40% to 76% of UEs occurred during the night shift [14,17,24,40]; many more occur during change of shift or when there is not a nurse present at the bedside [3,17]. Recent trends towards mandatory bedside reporting is a specific intervention that may positively impact UE among patients in the ICU [41]. Meta-analyses of observational studies investigating the effect of nurse staffing on hospital outcomes indicate that increasing the number of RNs is associated with decreased risk of adverse patient outcomes, including UE [42,43]. The addition of 1 additional nurse per patient day can result in a 51% decrease in UE, while a decrease in nursing workload could result in a 45% decrease in UE [42]. Data from a national prevalence study reports ICUs with fewer available resources, including staff, experienced a higher number of UEs [4].

Increasing surveillance by nursing and health care staff may also impact prevalence of physical restraint use. A significant number of patients who experience UE are physically restrained at the time of the incident, ranging from 40% to 90% of intubated patients [5–7,14,17,40]. It is well documented that UE continue to occur despite the use of restraints [5,7,28,29,44] Patients who are physically restrained often experience higher rates of unplanned extubation (42.9% vs. 16.5% , P < 0.001 in Chang et al’s study [7]), and longer ICU LOS (20.3 days vs. 15.8 days, P = 0.009) [7]. Soft wrist restraints are commonly used to prevent pulling of the endotracheal tube; however, research evidence on UE demonstrates this is not always an effective intervention. Increasing surveillance of ventilated patients, treating their agitation and screening for underlying delirium, and integration of weaning protocols are all interventions that may decrease UE and the need for routine use of physical restraints.

Ongoing Education for Patients and Health Care Staff

Initial and ongoing education about UE, risk factors, and effective interventions is beneficial for patients and health care staff. Although there are no trials investigating effects of educational interventions for patients on UE outcomes, pre-education of surgical patients regarding what to expect while intubated may aid in decreasing delirium risk, agitation, physical restraint use, and possibly UE. Verbal and written educational information during pre-admission testing is a feasible method easily integrated into pre-operative programs.

Because UEs often occur more frequently among less experienced staff, initial education about risk factors for UE is crucial to include in ICU staff orientation programs [3,7]. Educational initiatives should incorporate training on routine delirium screening and avoidance of agitation, use of protocols, and increased surveillance of patients receiving mechanical ventilation [5,15,17,39,45]. Ongoing education of staff regarding ventilatory equipment and risk factors for UE can be particularly effective in decreasing UE [46]. Initial educational efforts should be followed by routine updates for all members of the healthcare team about ongoing quality improvement efforts to monitor UE. Associated factors for UE that may be unit- or process-specific, including methods for endotracheal tube securement and intra-hospital transport, should be communicated with all individuals involved in patient care. Integration of continuous quality improvement programs can decrease UE rates by 22% to 53% [16]. Quality efforts typically focus on standardization of reporting and tracking tools, protocol implementations, and ongoing monitoring, auditing, and recording of UE.

Current Trends and Future Directions

Recent trends in critical care recommendations may mitigate potential risk factors identified in UE research. Integration of lightened sedation and daily wake up periods for intubated patients may decrease prevalence of risk factors for UE, specifically agitation, physical restraint use, and altered level of consciousness [30], while routine weaning protocols may improve ventilatory outcomes, including UE [5,38,40]. Nursing bedside report and purposeful hourly rounding are quickly emerging as mainstays of professional nursing care [41]. Inherent in these 2 initiatives are increased surveillance and vigilance by health care staff, which can result in timely extubation of those who indicate readiness, as well as decreased incidence of adverse events. Delirium remains a key factor that may be a likely cause for UE; recent trends towards early detection and proper management of delirium among ICU staff may result in improved ventilatory outcomes, including weaning, planned extubation, and the prevalence of UE.

Another important trend in critical care is the emergence of a neurocritical care specialty and routine admission of neurocritically ill patients to neuroscience ICUs [47,48]. However, there are no studies investigating prevalence of UE among these patients, who often have higher rates of agitation or restlessness due to cognitive impairment. Among general ICUs, patients with a primary respiratory diagnosis accounted for 23% of all UE in one study, while those with a neurological diagnosis accounted for the second highest percentage (12%) among the study population [15]. A separate study concluded that presence of neurological injury with a concomitant nosocomial infection increased risk of UE among patients in a mixed ICU [7]. A recent systematic review of weaning protocols highlights positive effects on ventilatory outcomes but cites lack of evidence for effectiveness of protocols among those with neurological injury [38]. Areas for future UE research should include factors specific to this patient population, as they may be at higher risk for adverse ventilatory outcomes due to the nature of the neurological injury.

Conclusion

Prevention of UE remains an elusive target, evidenced by little change in reported rates over 2 decades. Research provides data on risk factors that may be patient, unit, or process related. Structuring prevention efforts around modifiable risk factors for UE is a feasible approach amenable to ongoing monitoring for effectiveness. Integration of current trends in health care safety and quality may produce an added benefit of reducing the occurrence of UE in critical care units. Future research evaluating these trends and the prevalence of UE in subspecialty populations is warranted.

Corresponding author: Molly McNett, PhD, RN, CNRN, Attn: NBO, MetroHealth Medical Center, 2500 MetroHealth Drive; Cleveland, OH 44109, mmcnett@metrohealth.org.

Financial disclosures: None.