Use of cerebrospinal fluid lactate levels in the diagnosis of bacterial meningitis.

Ninety-two cerebrospinal fluids were analyzed by a simple gas-liquid chromatography method for lactic acid. The presence of greater than 30 mg/dl of lactic acid correlated with proven bacterial or cryptococcal meningitis. Elevated lactate levels were also found in two patients with suspected but not proven bacterial meningitis. In 78 patients who did not have bacterial meningitis the cerebrospinal fluid contained less than 30 mg/dl of lactic acid.