Rhabdomyolysis and myoglobinuric acute renal failure associated with classic heat stroke

Classic heat stroke is a disorder of thermal regulation that predominantly affects elderly patients during heat waves. In contrast to exertional heat stroke, rhabdomyolysis and myoglobinuric acute renal failure are considered to be unusual manifestations of classic heat stroke. We retrospectively reviewed the charts of seven patients admitted to Maimonides Medical Center with classic heat stroke over a 3-day period during a heat wave in July 1993. Three of these patients with classic heat stroke had rhabdomyolysis, but no renal failure; two completely recovered; and one had an ataxic gait disturbance. Three additional patients had rhabdomyolysis and myoglobinuric acute renal failure; one of them completely recovered, one survived with quadriplegia, and one died. Our findings suggest that rhabdomyolysis and myoglobinuric acute renal failure are common manifestations of classic heat stroke. Recognition of this complication warrants rigorous hydration and alkalinization of the urine to prevent or attenuate myoglobinuric acute renal failure.