Influence of prior illness on exertional heat stroke presentation and outcome

IntroductionPrecipitating factors that contribute to the severity of exertional heat stroke (EHS) are unclear. The purpose of this study was to determine the effect of prior illness (PI) on EHS severity.MethodsWe performed a retrospective clinical record review of 179 documented cases of EHS at the Marine Corps Base in Quantico, Virginia.ResultsApproximately 30% of EHS cases had a medically documented PI. Anthropometrics (height, weight, body mass index) and commonly associated risk factors for EHS (age, number of days in training, wet bulb globe temperature, sleep patterns) did not differ between PI and no illness (NI) groups. PI patients presented with higher maximal rectal core temperatures (40.6 ± 1.0°C vs. 40.3 ± 1.2°C; P = 0.0419), and elevated pulse rates (118.1 ± 16.7 bpm vs. 110.5 ± 24.2 bpm; P = 0.0397). At the point of care, biomarker values were similar between PI and NI groups, with the exception of a trend toward elevated monocytes in those with PI (7.9 ± 2.9% vs 6.7± 2.7%; P = 0.0521). Rate and duration of cooling were similar between PI and NI patients.ConclusionThis study indicates that PI has a minimal effect on the patient presentation, severity and treatment outcome of EHS. The results of this study have important implications for military, civilian, and occupational populations who are at risk for EHS.

引言：目前尚未明确影响劳力性热射病（exertional heat stroke, EHS）严重程度的诱发因素。本研究旨在探讨既往病史（prior illness, PI）对劳力性热射病严重程度的影响。
方法：对弗吉尼亚州匡蒂科海军陆战队基地记录在案的179例劳力性热射病病例开展回顾性临床病历审查。
结果：约30%的劳力性热射病病例存在经医学记录证实的既往病史。既往病史组与无病史（no illness, NI）组在人体测量学指标（身高、体重、体质量指数）及劳力性热射病常见相关危险因素（年龄、训练天数、湿球黑球温度（wet bulb globe temperature）、睡眠模式）方面无显著差异。既往病史组患者的最高直肠核心体温更高（40.6 ± 1.0℃ vs 40.3 ± 1.2℃；P = 0.0419），脉搏速率也更高（118.1 ± 16.7 bpm vs 110.5 ± 24.2 bpm；P = 0.0397）。在诊疗时点，两组患者的生物标志物（biomarker）水平相近，仅既往病史组单核细胞（monocytes）比例呈升高趋势（7.9 ± 2.9% vs 6.7 ± 2.7%；P = 0.0521）。两组患者的降温速率与降温持续时间无显著差异。
结论：本研究表明，既往病史对劳力性热射病的患者临床表现、严重程度及治疗结局影响极小。本研究结果对存在劳力性热射病风险的军事、民用及职业人群具有重要的指导意义。