A comparison of alfentanil, halothane and enflurane as supplements for outpatient urological surgery.

Seventy-seven patients presenting for outpatient cystoscopy participated in a trial to assess postoperative recovery when either alfentanil, halothane, or enflurane were used in combination with nitrous oxide/oxygen anaesthesia. Anaesthesia was uneventful in all cases. Apnoea occurred once with alfentanil, but naloxone was not required. Vomiting occurred once with alfentanil and once with enflurane. Anti-emetics were not required. Blood pressure and pulse rate variations from preoperative levels occurred with similar frequency in all groups. Times to open eyes, show left thumb, and give correct date of birth were significantly less with alfentanil than with the other agents tested. Trieger testing failed to demonstrate an advantage of alfentanil, although two patients in each of the halothane and enflurane groups were insufficiently recovered to complete the tests. As tested, alfentanil represents a useful alternative to halothane or enflurane as postoperative recovery of mental function is significantly more rapid than with the inhalational agents.