Effect of beta-adrenergic blockade with propranolol on cerebral blood flow, autoregulation and CO2 responsiveness.

Cerebral autoregulation and vasomotor responsiveness to carbon dioxide were measured quantitatively in normal baboons and after intravertebral or intravenous of the beta-adrenergic blocking agent, propranolol hydrochloride (Inderal). Continuous measurements were made of cerebral blood flow (CBF: measured as bilateral internal jugular venous outflow using an electromagnetic flowmeter), cerebral perfusion pressure (CPP), arterial Po2 and Pco2 and venous Po2, cerebral arteriovenous oxygen difference and endotracheal Pco2. The autoregulation index (A.I. = deltaCBF/deltaCPP) and the chemical index (C.I.= deltaCBF/deltaPaco2), were used as quantitative measures.