Cerebral complications following induced hypotension.

Over an 8-year period (1977-1984), 1,802 otorhinolaryngological procedures were performed under controlled hypotension. Four patients showed symptoms of cerebral damage post-operatively. One patient had pre-operative unrecognized stenosis of the internal carotid artery, another a hypoplastic vertebral artery. In this female patient, the head had been strongly rotated to the side to expose the surgical field, and the internal jugular vein removed. She died of general ischaemic brain damage on the seventh post-operative day. In the remaining two patients, symptoms of cerebral ischaemia did not occur until the third and eleventh day, respectively, so that the causative role of hypotensive anaesthesia is uncertain. The cases described represent a cerebral morbidity of 4:1,802 (0.22%) and a mortality of 1:1,802 (0.06%). It is concluded that controlled hypotension is a safe technique if the indication is stringently applied, and any risk-bearing factors are carefully excluded.