Inhalation of oxygen and carbon dioxide gas. Effect on composition of cerebral venous blood

Publisher Website
Google Scholar
Abstract
Inhalation of various gas mixtures was used to challenge the capacity of cerebral vasomotor reactivity in subjects with and without cerebrovascular disease and of different age groups. Effects of inhalation of 100% O2 5% CO2 plus O2 and 5% CO2 plus air on the composition of arterial and jugular blood were measured. Blood PO2 [O2 tension], PCO2 [CO2 tension], and pH were continuously recorded. The increase of cerebral venous PO2 after inhalation of 100% O2 or 5% CO2 phis O2 was far less than that in arterial blood. Inhalation 100% O2 caused a slight increase in arterial PCO2 due to the Haldane effect. The increase of cerebral venous PO2 by inhalation of 5% CO2 in air was significantly higher in the group over 35 yr. than in the younger group. In the presence of cerebral arteriovenous malformation, the rise of cerebral venous PO2 caused by 100% O2 inhalation was significantly higher than that found in the absence of vascular disease to the brain due to arteriovenous shunting. In occlusive cerebrovascular disease, elevation of cerebral venous PO2 after inhalation of 5% CO2 plus O2 or 5% CO2 phis air was significantly smaller than that found in subjects without cerebrovascular disease but nevertheless occurred. In the presence of carotid occlusion, the increase of cerebral venous PO2 induced by inhalation of 5% CO2 plus air was significantly smaller than found in subjects with middle cerebral artery occlusion or stenosis of cerebral vessels. There was no significant difference between the latter 2 groups. No relationship was found between the state of consciousness or any electroencephalogram abnormality and the cerebral vasomotor response to the challenge gas mixtures. Inhalation of 100% O2 or 5% CO2 plus O2 increased the O2 available to the ischemic or anoxic brain and appeared to be a justifiable form of therapy in occlusive cerebrovascular disease (stroke).

This publication has 1 reference indexed in Scilit: