Mortality of patients with heatstroke admitted to intensive care units during the 2003 heat wave in France: A national multiple-center risk-factor study*

Abstract

OBJECTIVE: Heatstroke requires active body cooling and organ failure supportive care. Although heat waves are expected to recur over the next decades, little is known about the risk factors for mortality in heatstroke patients. We examined the prognosis and risk factors for hospital mortality in patients with heatstroke admitted to an intensive care unit (ICU) during the heat wave in France in August 2003. DESIGN: A questionnaire was sent to the physicians leading an ICU in France to identify the patients admitted with heatstroke during August 2003. Data included demographics, factors predisposing to heatstroke, severity during the first day in the ICU, air conditioning in the ICU, and hospital mortality. Risk factors for mortality were determined in multivariate Cox proportional hazards analysis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Data were obtained for 345 patients. Hospital mortality was 62.6%. Occurrence of heatstroke at home or in a healthcare facility rather than in a public location, high Simplified Acute Physiology Score II, high body temperature, prolonged prothrombin time, use of vasoactive drugs within the first day in the ICU, and patient management in an ICU without air conditioning were independently associated with an increased risk of death. CONCLUSIONS: Mortality of patients admitted to the ICU with heatstroke is high. Predictors of mortality are available within the first 24 hrs after admission. Furthermore, in this study, air conditioning in the ICU was associated with improved outcome.