Prognostic factors in non-exertional heatstroke
To identify the prognostic factors associated with mortality in heat-related illness.
Multi-center observational cohort-study in 16 emergency departments (ED) belonging to the teaching hospital network of the Paris area. The cohort comprised all patients admitted to one of the EDs during the August 2003 heat wave in Paris and having a core temperature >38.5°C. Baseline clinical and biological data in ED, patient’s course and 1-year survival rate were recorded. Potential prognostic factors associated with death were assessed by Cox proportional-hazards analysis.
A total of 1,456 patients were included. Mean age was 79 ± 19 years. Critically ill conditions were noted in 391 patients (27%), but only 72 (5%) were admitted into an intensive care unit. The survival rate was 57% at 1 year as compared to an expected 90% (P < 0.001). Nine independent prognostic factors were identified: previous treatment with diuretics, living in an institution, age >80 years, cardiac disease, cancer, core temperature >40°C, systolic arterial pressure <100 mmHg, Glasgow coma scale <12 and transportation to hospital by ambulance. We defined three risk groups: low, intermediate and high risk, with a 1-year survival rate of 85, 61 and 18%, respectively.
We observed a low survival rate and developed a risk score based on easily obtained variables that may be useful to clinicians managing casualties from future heat waves.
KeywordsHeatstroke Heat wave Risk factors Elderly patients Mortality Temperature
We are indebted to Emmanuelle de Magondeau and Christine Lanau for their excellent data monitoring and management. We thank Dr. David J. Baker, DM, FRCA (Department of Anesthesiology, CHU Necker-Enfants Malades, Paris, France) for reviewing the manuscript and Prof. Paul Landais, MD, PhD (Department of Biostasistics, CHU Necker-Enfants Malades, France) and Yannick Le Manach (Department of Anesthesiology and Critical Care, CHU Pitié-Salpêtrière, Paris, France) for statistical advice. The study was supported by the Direction Régionale de la Recherche Clinique d’Ile de France (Paris, France), grant no. CRC 03-150.
Conflict of interest statement
The authors declare that they have no conflict of interest.
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