Acid-base balance and arterial and CSF lactate levels following human head injury

Abstract

✓ Sequential arterial and cerebrospinal fluid (CSF) lactate, pH, pCO 2 , HCO 3 − , and pO 2 levels were determined for 4 days in 17 patients immediately following uncomplicated head injury. Lactate was initially markedly elevated in both fluids and decreased by the third day after injury. There was mild arterial metabolic acidosis and respiratory alkalosis on admission; the alkalosis continued. Arterial pO 2 was below normal at all times. The CSF showed a normal pO 2 , and metabolic acidosis related to lactate accumulation. Blood and CSF pCO 2 and HCO 3 − levels equilibrated well, probably because of the time factor; CSF and arterial pO 2 levels were not significantly related. The clinical implications of CSF lacticacidosis after head injury are discussed.