The diagnostic and prognostic significance of the serum enzyme changes in heatstroke

Serum transaminase (SGOT, SGPT), lactic dehydrogenase (LDH) and creatine phosphokinase (CPK) levels were measured serially in 84 Bantu gold-miners with a provisional diagnosis of heatstroke. In 75 patients proved to have heatstroke, SGOT levels were invariably, and SGPT, LDH and CPK values almost invariably, elevated within 24 hours of admission. The levels continued to rise for approximately 48 hours and remained elevated for average periods of 12 to 14 days. In the patients who proved to have acute infections, SGOT, SGPT and LDH values were normal. The serum enzyme changes were therefore useful in confirming or excluding the diagnosis of heatstroke. The degree of elevation of the enzyme levels was also a reliable index of the severity of tissue damage in heatstroke and hence the patient's likely outcome. In 15 patients in whom the SGOT level exceeded 1,000 units in the first 24 hours, renal, hepatic and cerebral damage tended to be severe, and death or permanent sequelae were common. In 20 patients with SGOT values of less than 1,000 units, the tissue injury was usually mild or moderate and completely reversible, and there was only 1 death.