Validity of Bispectral Index Monitoring in Controlled Hypotensive Anesthesia

Abstract

In a single blind study of 20 ASA 1 patients undergoing rhinoplastic surgery under controlled hypotensive anesthesia in Rumailah Hospital, Qatar, on reaching the steady state of anesthesia the mean arterial blood pressure (MAP) was adjusted to the lower accepted limit (40-50 mm.Hg) using esmolol infusion. The MAP and bispectral index (BIS) were continuously recorded together with all essential monitoring perioperatively. A significant correlation was observed between the MAP and BIS at mean blood pressure below 45 mm.Hg. Conclusion: BIS is a multivariant derived EEG device designed to monitor the state of consciousness under different hypnotic agents and could be a useful monitor during hypotensive anesthesia.