Recovery after oral surgery with halothane, enflurane, isoflurane or propofol anaesthesia

We have compared the recovery characteristics of four different techniques for maintenance of anaesthesia in 99 day-case patients admitted for oral surgery. All patients received propofol for induction of anaesthesia followed by halothane, enflurane, isoflurane or propofol infusion for maintenance of anaesthesia. Each patient was subjected to a battery of psychometric tests which included Spielberger state, trait, mood stress and mood arousal questionnaires, Maddox-Wing test and five-choice serial reaction time. All tests were performed before operation and at 0.5, 1, 2, 4, 24 and 48 h after operation. Performance in the reaction time test decreased significantly in the immediate postoperative period, returning almost to preoperative values by 4 h. However, only those patients who received enflurane or propofol had returned to their performance level before surgery by 4 h, although all four groups had achieved this target by 24 h. There was a further improvement in performance at 48 h. Anxiety and stress were high before surgery and decreased rapidly in the postoperative period. The Maddox-Wing test demonstrated a significant impairment in performance in the first 1 h after surgery, which returned to normal by discharge at 4 h. There were no significant differences between the four groups in these latter tests.