Comparison of propofol with enflurane during hypotensive anaesthesia for middle ear surgery

Forty patients undergoing middle ear surgery were allocated randomly to receive propofol induction and maintenance, or thiopentone induction and enflurane maintenance for anaesthesia. Both groups also received fentanyl, alcuronium, nitrous oxide and oxygen. If this did not reduce systolic arterial pressure to 70 mm Hg, labetalol, glyceryl trinitrate (GTN), or both, was administered. Fifteen control patients had enflurane anaesthesia without hypotension. Pre- and postoperative psychometric tests were performed in all groups. The propofol group received significantly more labetalol (P = 0.014) and GTN (P = 0.004) than the enflurane group. There was a greater increase in reaction times after operation in the study groups (P < 0.05) compared with controls. There was no difference between the propofol and enflurane groups in control of arterial pressure, recovery from anaesthesia or psychometric testing.