Cerebrospinal fluid lactate and lactate/pyruvate ratios in hydrocephalus.

Cerebral metabolism in 21 hydrocephalic patients was studied. Preoperative and postoperative specimens of cerebrospinal fluid (CSF) were obtained and the cerebral perfusion pressure (CPP) was calculated in each instance. The specimens of CSF were analyzed for lactate and pyruvate and the lactate/pyruvate (L/P) ratio was calculated for each sample. The L/P ratio, which reflects the redox state of the cell, was used to determine the extent of anaerobic metabolism. An inverse relationship was noted between CPP and lactate as well as the L/P ratio. In general, the level of anaerobic metabolism was decreased after insertion of a shunt.