Abstract
Summary This research deals with the gaseous and biochemical changes in the cerebrospinal fluid and their effects on the cerebral blood flow and metabolic rates in the acute stage of brain injury. The results have shown that the lactacidosis in the CSF is of importance for prognosis and therapy, because of its central position in the course of pathophysiological mechanisms after a traumatic brain injury. Thus the lactate concentration in the CSF does give early information about the further clinical course. CSF acidosis itself can be influenced in a favourable way by intrathecal therapy with sodium bicarbonate.