Chronic derangements of cerebrospinal fluid acid-base components in man

Abstract

In a group of normal subjects a relative respiratory acidosis in the cerebrospinal fluid (CSF) as compared with arterial blood was found. There was no significant gradient for bicarbonate concentrations between the two compartments. In normal subjects under high-altitude adaptation, arterial and CSF respiratory alkalotic shifts were similar. A concomitant fall in bicarbonate levels was slightly less in CSF than in arterial blood. In a group of patients with uremic acidosis the arterial-cerebrospinal H ion gradient was reversed, as bicarbonate was significantly less reduced in CSF relative to arterial blood. Hemodialysis led to restitution of the relative respiratory acidosis in CSF. These findings seem to indicate fast diffusion of CO 2 across the cerebrospinal-arterial barrier. In contrast, diffusion of bicarbonate and/or H ion appears to be delayed and incomplete. CSF acid-base components are not likely to correlate with stimulation of the respiratory centers under these conditions. Submitted on March 12, 1962