TOWARDS A STANDARDIZED ANESTHETIC STATE USING ISOFLURANE AND MORPHINE

In 34 patients undergoing major surgery, the inspired isoflurane conce ntration was adjusted by a control system designed to maintain systoli c arterial pressure at a predetermined value. An empirical rule allowe d additional morphine administration if the demand of the system for i soflurane was excessive. Satisfactory control of systolic arterial pre ssure was achieved in 31 patients and the anaesthetic state was clinic ally acceptable to an independent observer; no awareness was reported and the mean recovery time was 9.6 min. In these patients, control of systolic arterial pressure produced a pattern of clinical signs recogn izable as general anaesthesia.