Fentanyl supplementation to inhalation anaesthesia

In eight out of 15 healthy patients undergoing body surface surgery, the effect of a fentanyl infusion on a conventional thiopentone, nitrous oxide, oxygen and halothane anaesthetic was studied. The fentanyl infusion (2 micrograms/kg/hour) reduced the induction dose of thiopentone and caused marked respiratory depression with a reduction in the patients' response to surgery. The mean arterial pressures and pulse rates were not significantly different in each group throughout the course of the operation. The fentanyl made no difference to the patients' postoperative analgesic requirements or to their recovery in the first 24 hours.