Lactic acidemia in Reye's syndrome.

Plasma lactate level was measured in 21 patients with Reye's syndrome and was compared with neurologic state as rated on a simple coma scale. Significant elevations in plasma lactate, ranging from 2 to 15 mEq/liter, were noted in all patients. There was a close correspondence between stage of coma at the time the sample was drawn and lactate levels. The correlation of plasma lactate level with clinical stage could not be accounted for by differences in glucose. PO2, PCO2, pH, blood pressure, or serum osmolality. In contrast, blood ammonia level correlated with the severity of the encephalopathy early in the course only and often returned to normal in patients with persistent coma. Only measurements of hepatic dysfunction such as SGOT and SGPT levels of failed to correlate with clinical state. All patients had a metabolic acidosis; in five patients it was uncompensated. Lactate accounted for nearly all (mean 81%) of the observed base deficit. The findings suggest that lactic acidemia is an important metabolic component of Reye's syndrome.