Exertional heat stroke: clinical characteristics and courses of 15 patients

Lee, Sang Ho; Yoo, Tae Hyun; Kim, Byung Hoe; Kim, Kwang Gi

Abstract

BACKGROUND
Heat stroke is a life-threatening emergency and manifested principally by hyperthermia and central nervous system dysfunction. Exertional heat stroke seems to be more predominant type in Korea, considering its temperate climate. We undertook this study to evaluate the clinical characteristics and courses of exertional heat stroke.
METHODS
Serial clinical and laboratory data were collected and analyzed in 15 patients with exertional heat stroke from April 2000 to October 2001.
RESULTS
Most episodes occurred after heavy exercise during periods of high ambient temperature and humidity. Especially 11 patients (73.3%) were unacclimatized recruits in basic training. Victims showed a characteristic clinical feature such as high core body temperature (>40degrees C), altered mental status and frequent shock (7 cases). Common abnormal laboratory findings were: elevated serum CPK, LDH, AST and myoglobin, elevated ALT, leukocytosis, thrombocytopenia, metabolic acidosis and typical electrocardiographic abnormalities. All patients presented with normal or hypokalemic state (50%), although they were complicated with renal failure, rhabdomyolysis and metabolic acidosis. Heat stoke induced multiple organ failure such as rhabdomyolysis (93.3%), acute renal failure (73.3%), disseminated intravascular coagulation (46.7%), myocardial ischemia (28.6%) in addition to central nervous system dysfunction. Three patients (20%) died and 3 patients among survivors suffered from persisting CNS dysfunction, especially cerebellar dysfunction.
CONCLUSION
Heat stroke is a fatal emergency with high mortality and morbidity. Heat stroke should be suspected in any person who collapses during physical activity, especially on a hot and humid day and the prompt initiation of appropriate treatment is demanded.