Prevention of cerebral ischaemia under general anaesthesia.

General anaesthesia influences the oxygen supply/demand ratio of the brain and may thus be able to improve neurological outcome after carotid artery surgery. Among the anaesthetic agents, barbiturates and isoflurane produce a marked reduction of the cerebral metabolic rate and activity. But the incidence of neurological deficits in the immediate postoperative period is low, while the possible causes of any neurological deficits are multiple. Consequently, to date, no particular anaesthetic agent or management has been shown to influence the neurological results.