Francis G. O’Connor

Exertional heat stroke: new concepts regarding cause and care

Abstract When athletes, warfighters, and laborers perform intense exercise in the heat, the risk of exertional heat stroke (EHS) is ever present. The recent data regarding the fatalities due to EHS within the confines of organized American sport are not promising: during the past 35 years, the highest number of deaths in a 5-year period occurred from 2005 to 2009. This reminds us that, regardless of the advancements of knowledge in the area of EHS prevention, recognition, and treatment, knowledge has not been translated into practice. This article addresses important issues related to EHS cause and care. We focus on the predisposing factors, errors in care, physiology of cold water immersion, and return-to-play or duty considerations.

Functional Movement Screen and Aerobic Fitness Predict Injuries in Military Training

PURPOSE This study investigated associations between injuries and individual components of the Marine Corps physical fitness test (PFT), self-reported exercise and previous injury history, and Functional Movement Screen (FMS) scores. METHODS A cohort of 874 men enrolled in either 6 wk (n = 447) or 10 wk (n = 427) of Marine Corps officer candidate training was recruited. They completed an exercise history questionnaire, underwent an FMS during medical in-processing, and completed the standardized PFT (pull-ups, abdominal crunch, and 3-mile run) within 1 wk of training. Injury data were gathered throughout training from medical records and classified into overuse, traumatic, and any injury. RESULTS Three-mile run time (RT) was the only PFT component predictive of injury: candidates with RT ≥20.5 min were 1.7 times (95% confidence interval = 1.29-2.31, P < 0.001) more likely to experience an injury compared with those with RT <20.5 min. Prior injury, frequency of general exercise and sport participation, and length of running history were predictive of any, overuse, and traumatic injuries, respectively. Combining slow RT and low FMS scores (≤14) increased the predictive value across all injury classifications: candidates scoring poorly on both tests were 4.2 times more likely to experience an injury. The pull-up to exhaustion test was related to four of the seven FMS tests and the only PFT test positively related to total FMS score, although correlations were generally low (r ≤ 0.11). CONCLUSION Slow RT was associated with increased injury risk, and combining poor RT and low FMS scores significantly increased the injury predictive value. Additional research is warranted to further clarify what combination of PFT and FMS tests are most suitable for predicting injuries.

Acsm and Champ Summit on Sickle Cell Trait: Mitigating Risks for Warfighters and Athletes

INTRODUCTION An estimated 300 million people worldwide have sickle cell trait (SCT). Although largely benign, SCT has been associated with exertional rhabdomyolysis and exercise-related sudden death in warfighters/athletes (WA). The National Collegiate Athletic Associations policy to confirm a student athletes SCT status during their preparticipation medical examination prompted reaction from some organizations regarding the rationale and ethical justification of the policy. METHODS On September 26 and 27, 2011, a summit, composed of military and civilian experts in sports medicine and SCT, was convened at the Uniformed Services University in Bethesda, MD. The expert panel was charged with two objectives: 1) to provide specific recommendations to further mitigate the apparent risk with strenuous exercise in WA with SCT and 2) to develop clinical guidelines to identify, treat, and return to duty/play WA suspected to have incurred nonfatal sickle cell collapse. RESULTS New terminology is introduced, areas of current controversy are explored, consensus recommendations for mitigating risk and managing the WA with SCT are reviewed, and important areas for future research are identified. CONCLUSION Further research is needed before conclusions can be drawn regarding the etiology of the increased death rate observed in WA with SCT, and the possibility exists that SCT is a surrogate for as yet another contributing factor for the unexplained deaths.

Mass Participation Event Management for the Team Physician: A Consensus Statement

DEFINITION Mass participation event management is medical administration and participant care at these sporting events. Medical management provides safety advice and care at the event that accounts for large numbers of participants, anticipated injury and illness, variable environment, repeated games or matches, and mixed age groups of varying athletic ability. This document does not pertain to the care of the spectator. GOAL The goal is to assist the team/event physician in providing medical care during mass participation events. The physician’s role is to organize a medical team that facilitates event safety, provides medical care, makes return-to-participation decisions, and acts as the event medical spokesperson. To accomplish this goal, the team physician should have knowledge of and be involved with • Administrative matters concerning the event • Medical care and protocols • Hydration and fluid replacement SUMMARY This document provides an overview of select medical issues that are important to team physicians who are responsible for mass participation event management. It is not intended as a standard of care, and should not be interpreted as such. This document is only a guide, and as such, is of a general nature, consistent with the reasonable, objective practice of the healthcare professional. Individual treatment will turn on the specific facts and circumstances presented to the physician. Adequate insurance should be in place to help protect the physician, the athlete, and the sponsoring organization. This statement was developed by a collaboration of six major professional associations concerned about clinical sports medicine issues; they have committed to forming an ongoing project-based alliance to bring together sports medicine organizations to best serve active people and athletes. The organizations are American Academy of Family Physicians,

Consortium for Health and Military Performance and American College of Sports Medicine Summit: Utility of Functional Movement Assessment in Identifying Musculoskeletal Injury Risk

Prevention of musculoskeletal injuries (MSKI) is critical in both civilian and military populations to enhance physical performance, optimize health, and minimize health care expenses. Developing a more unified approach through addressing identified movement impairments could result in improved dynamic balance, trunk stability, and functional movement quality while potentially minimizing the risk of incurring such injuries. Although the evidence supporting the utility of injury prediction and return-to-activity readiness screening tools is encouraging, considerable additional research is needed regarding improving sensitivity, specificity, and outcomes, and especially the implementation challenges and barriers in a military setting. If selected current functional movement assessments can be administered in an efficient and cost-effective manner, utilization of the existing tools may be a beneficial first step in decreasing the burden of MSKI, with a subsequent focus on secondary and tertiary prevention via further assessments on those with prior injury history.

Exertional Heat Illness: The Role of Heat Tolerance Testing

Exertional heat stroke (EHS) is a common clinical problem for both athletes and warriors; however, evidence-based guidance for return-to-play/duty (RTP/RTD) decisions is limited. Heat tolerance testing (HTT) has been proposed as a potential tool that, when combined with appropriate clinical information, may assist in RTP/RTD decisions. However, currently, no standard of care is available for performing HTT. The Israeli Defense Forces (IDF) HTT protocol, which was developed over decades of careful research, has proven useful for IDF warriors and is utilized by other militaries to assist in RTD decisions. The present case studies are used to discuss the efficacy of the IDF HTT in determining RTD for two warriors who experienced EHS. Strengths and limitations of the IDF HTT, along with current and potential roles in clinical decision-making and in future thermoregulation research, are discussed.

Hypertension, athletes, and the sports physician: implications of JNC VII, the Fourth Report, and the 36th Bethesda Conference Guidelines.

Over the past decade, numerous studies have contributed to a growing evidence-based recommendation that the prevention, diagnosis, and management of hypertension can significantly lower cardiovascular morbidity and mortality. Several leading guidelines have been updated recently. Because hypertension is a common cardiovascular disease in athletes, sports medicine providers must remain vigilant in diagnosing this disorder and current with treatment and participation recommendations.

Exercise collapse associated with sickle cell trait (ECAST): case report and literature review.

Sickle cell trait (SCT) has been associated with exertional collapse (ECAST) and exercise-related sudden death in athletes and military warfighters. The mechanisms underlying ECAST remain controversial in the sports medicine community. Multiple case presentations and anecdotal reports postulate the role of extraordinary exercise intensity, but other risk factors including dehydration, heat, previous exertional rhabdomyolysis, genetic cofactors, and dietary supplements have been cited as potential contributors. Others have hypothesized some of the aforementioned factors combining in a “perfect storm” to trigger ECAST with a resultant potentially fatal “metabolic crisis.” This case report provides a brief review of SCT as it pertains to exercise in warfighters and athletes, identifies known and postulated risk factors associated with ECAST, and introduces the potential mechanistic role of the “double hit” as a contributor to ECAST.

Challenging return to play decisions: heat stroke, exertional rhabdomyolysis, and exertional collapse associated with sickle cell trait

Context: Sports medicine providers frequently return athletes to play after sports-related injuries and conditions. Many of these conditions have guidelines or medical evidence to guide the decision-making process. Occasionally, however, sports medicine providers are challenged with complex medical conditions for which there is little evidence-based guidance and physicians are instructed to individualize treatment; included in this group of conditions are exertional heat stroke (EHS), exertional rhabdomyolysis (ER), and exertional collapse associated with sickle cell trait (ECAST). Evidence Acquisition: The MEDLINE (2000-2015) database was searched using the following search terms: exertional heat stroke, exertional rhabdomyolysis, and exertional collapse associated with sickle cell trait. References from consensus statements, review articles, and book chapters were also utilized. Study Design: Clinical review. Level of Evidence: Level 4. Results: These entities are unique in that they may cause organ system damage capable of leading to short- or long-term detriments to physical activity and may not lend to complete recovery, potentially putting the athlete at risk with premature return to play. Conclusion: With a better understanding of the pathophysiology of EHS, ER, and ECAST and the factors associated with recovery, better decisions regarding return to play may be made.

Syncope/presyncope in the competitive athlete

Syncope is a relatively common event in the general population and is not infrequently encountered in athletes. The pathophysiology of all forms of syncope consists of a sudden decrease in cerebral blood flow, though there are many other mechanisms for transient loss of consciousness (TLOC).