Cerebrospinal Fluid and Arterial Lactate, Pyruvate and Acid-Base Balance in Patients With Intracranial Hemorrhages

Abstract

Lactate and pyruvate concentrations and acid-base balance in cerebrospinal fluid (CSF) and arterial blood were determined in patients with intracranial hemorrhages (28 subarachnoid hemorrhages and 15 intracerebral hemorrhages). A greater increase in CSF lactate and lactate-pyruvate ratio (L/P ratio) was observed in patients with impairment of consciousness, focal neurological deficits, poor prognosis, or CSF pressures higher than 300 mm H₂O. A combination of CSF lactate greater than 2.5 mM per liter, L/P ratio above 20, bicarbonate less than 20.4 mEq per liter, pH below 7.276, or arterial PCO₂ below 31.5 mm Hg seems to indicate a poor prognosis from intracranial hemorrhage. The mechanism of hyperventilation in acute cerebrovascular diseases and of CSF pH regulation in acid-base disturbances was also discussed.