Pathogenesis, Pathobiology and Treatment of Exertional Heat Injury/Stroke
There is little data available comparing initial treatment measures for exertional heat stroke (EHS). Traditional treatment protocols (TTP) at a military installation consisted of evaporative cooling. An iced-sheet cooling and evacuation protocol (ICEP) was implemented in selected units that utilized an emphasis on immediate cooling measures and evacuation.
To determine the impact of the ICEP on the risk of the development of cell lysis syndrome (renal insufficiency, acute hepatic necrosis and rhabdomyolysis) and death.
A retrospective cohort study at a military installation reviewing all cases of EHS from 2001–2002. Two of the units utilized the ICEP which emphasizes prompt determination of core temperature when a soldier presents with mental status changes. Rapid cooling with iced-water soaked cotton sheets is required for all patients with a core temperature greater than 40C(104 F). The soldier is undressed to briefs, wrapped in the iced sheets, and then the sheets are removed and the soldier is fanned. Evacuation is initiated as cooling starts. Cooling is stopped when core temperature reaches (37C)100F. The TTP cohort was cooled via removal of clothing, drenched with room temperature water, and fanned. Core temperature determination was accomplished upon arrival of EMS.
There were 21 EHSs during the study period that were treated with one of the two protocols. Ten EHSs occurred in the ICEP cohort. Eleven EHSs occurred in the TTP cohort. All subjects were healthy males with an age distribution of 18–36. The incidence of cell lysis syndrome (CLS) was zero percent in the ICEP cohort and 36.3% (n = 4) in the TTP cohort. The odds ratio for the development of CLS in the ICEP cohort was .636 (CI .407–.995). The incidence of death was zero in the ICEP cohort and 9.1% (n = 1) in the TTP cohort. The odds ratio for death in the ICEP cohort was .500 (CI .323–.775).
In this study, the ICEP is associated with a decreased risk for CLS and death. Further education of trainers, coaches and medical personnel emphasizing the importance of recognition of symptoms of serious heat injury, initiating evacuation and rapid cooling may reduce the morbidity and mortality associated with EHS.