1.
Should Cooling Vests Be Used to Treat Exertional Heatstroke? A Critically Appraised Topic.
Keen, ML, Miller, KC
Journal of sport rehabilitation. 2017;(3):286-289
Abstract
UNLABELLED Clinical Scenario: Exercise performed in hot and humid environments increases core body temperature (TC). If TC exceeds 40.5°C for prolonged periods of time, exertional heat stroke (EHS) may occur. EHS is a leading cause of sudden death in athletes. Mortality and morbidity increase the longer the patient's TC remains above 40.5°C; thus, it is imperative to initiate cooling as quickly as possible. Acceptable cooling rates in EHS situations are 0.08-0.15°C/min, while ideal cooling rates are above 0.16°C/min. Cooling vests are popular alternatives for cooling hyperthermic adults. Most vests cover the anterior and posterior torso and have varying numbers of pouches for phase-change materials (eg, gel packs); some vests only use circulating water to cool. While cooling vests offer several advantages (eg, portability), studies demonstrating their effectiveness at rapidly reducing TC in EHS scenarios are limited. CLINICAL QUESTION Are TC cooling rates acceptable (ie, >0.08°C/min) when hyperthermic humans are treated with cooling vests postexercise? SUMMARY OF FINDINGS No significant differences in TC cooling rates occurred between cooling vests and no cooling vests. Cooling rates across all studies were ≤0.053°C/min. Clinical Bottom Line: Cooling vests do not provide acceptable cooling rates of hyperthermic humans postexercise and should not be used to treat EHS. Instead, EHS patients should be treated with cold-water immersion within 30 min of collapse to avoid central nervous system dysfunction and organ failure. Strength of Recommendation: Strong evidence (eg, level 2 studies with PEDro scores ≥5) suggests that cooling vests do not reduce TC quickly and thus should not be used in EHS scenarios.
2.
Heat injury prevention--a military perspective.
Epstein, Y, Druyan, A, Heled, Y
Journal of strength and conditioning research. 2012;:S82-6
Abstract
Heat-related injuries, and specifically exertional heat stroke, are a significant occupational risk in the armed forces, especially for those soldiers who are rapidly deployed from a temperate climate region to hot climate regions. Traditionally, adaptation to heat was considered as a matter of physiological adaptation. It is clear today that these injuries are mostly avoidable when applying proper education and behavioral adaptations. Education on behavioral adaptation for the prevention of heat injuries should be targeted at the individual and the organization level. This article summarizes the issue of proper preventive measures that should be taken to avoid, or at least minimize, the risk of exertional heat related injuries during military operations and training.
3.
Diseases associated with altered ryanodine receptor activity.
Durham, WJ, Wehrens, XH, Sood, S, Hamilton, SL
Sub-cellular biochemistry. 2007;:273-321
Abstract
Mutations in two intracellular Ca2+ release channels or ryanodine receptors (RyR1 and RyR2) are associated with a number of human skeletal and cardiac diseases. This chapter discusses these diseases in terms of known mechanisms, controversies, and unanswered questions. We also compare the cardiac and skeletal muscle diseases to explore common mechanisms.
4.
Cooling methods used in the treatment of exertional heat illness.
Smith, JE
British journal of sports medicine. 2005;(8):503-7; discussion 507
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Abstract
OBJECTIVE To review the different methods of reducing body core temperature in patients with exertional heatstroke. METHODS The search strategy included articles from 1966 to July 2003 using the databases Medline and Premedline, Embase, Evidence Based Medicine (EBM) reviews, SPORTDiscus, and cross referencing the bibliographies of relevant papers. Studies were included if they contained original data on cooling times or cooling rates in patients with heat illness or normal subjects who were subjected to heat stress. RESULTS In total, 17 papers were included in the analysis. From the evidence currently available, the most effective method of reducing body core temperature appears to be immersion in iced water, although the practicalities of this treatment may limit its use. Other methods include both evaporative and invasive techniques, and the use of chemical agents such as dantrolene. CONCLUSIONS The main predictor of outcome in exertional heatstroke is the duration and degree of hyperthermia. Where possible, patients should be cooled using iced water immersion, but, if this is not possible, a combination of other techniques may be used to facilitate rapid cooling. There is no evidence to support the use of dantrolene in these patients. Further work should include a randomised trial comparing immersion and evaporative therapy in heatstroke patients.