Comparison of alfentanil, fentanyl and enflurane as supplements to general anaesthesia for outpatient gynaecologic surgery.

We compared two narcotic/N2O anaesthetic techniques and an inhalational anaesthesia/N2O technique for outpatient surgery in 59 women undergoing short gynaecological procedures. All patients received droperidol 0.625 mg IV, thiopentone and 70 per cent N2O in O2 plus either alfentanil (15 micrograms.kg-1), fentanyl (1.5 microgram.kg-1) or enflurane. The narcotics were given in a double-blind fashion and all anaesthetic techniques were assigned randomly. Cardiorespiratory parameters remained stable in all groups, with few clinically important changes occurring. Recovery was significantly faster in the group receiving alfentanil, with the time to respond to verbal commands and the time to establish alertness significantly faster than with either fentanyl or enflurane. All techniques provided satisfactory anaesthesia; however, the patients receiving alfentanil had significantly more adverse events than those receiving fentanyl.