Autoregulation of Cerebral Blood Flow During Controlled Hypotension

Controlled hypotension has played a useful and at times valuable part in neurosurgical operations since 1946, when Gardner (5) first used arteriotomy to facilitate the removal of a large olfactory groove meningioma. Some seven years later Wiklund (15) recommended the use of pharmacologically induced hypotension in the treatment of vascular intracranial lesions. At the present time, despite the widespread use of the technique, considerable disagreement still exists regarding its safety (3, 13), the primary objections stemming from uncertainties regarding the adequacy of cerebral tissue perfusion during the periods of lowered blood pressure. The present investigations were undertaken to measure the effects of a graded, but progressive, reduction in systemic arterial pressure on the cerebral blood flow of anesthetized baboons.