ANALGESICS AND ENT SURGERY

1 Vomiting and restlessness following ENT and eye surgery are undesira ble, and may be related to the emetic and analgesic effects of any ana lgesic given to augment anaesthesia during surgery. 2 To rationalise t he choice of analgesic for routine ENT surgery we examined the intraop erative, recovery and postoperative effects following the administrati on of either buprenorphine (3.0 to 4.5 mu g kg(-1)), diclofenac (1 mg kg(-1)), fentanyl (1.5 to 2.0 mu g kg(-1)), morphine (0.1 to 0.15 mg k g(-1)), nalbuphine (0.1 to 0.15 mg kg(-1)), pethidine (1.0 to 1.5 mg k g(-1)) or saline (as control) given with the induction of anaesthesia in 374 patients. A standardised anaesthetic technique with controlled ventilation using 0.6-0.8% isoflurane in nitrous oxide and oxygen was employed. The study population constituted 7 similar groups of patient s. 3 Intraoperatively, their effects on heart rate and blood pressure, airway pressure and intraocular pressure, were similar. This implies, most surprisingly, that neither their analgesic nor their histamine r eleasing effects were clinically evident during surgery. By prolonging the time to extubation at the end of anaesthesia, only buprenorphine, fentanyl, morphine and pethidine provided evidence of intraoperative respiratory depression. 4 Postoperatively, buprenorphine was associate d with severe respiratory depression, prolonged somnolence, profound a nalgesia and the highest emesis rate. Diclofenac exhibited no sedative , analgesic, analgesic sparing, emetic or antipyretic effects. Fentany l provided no sedative or analgesic effects, but was mildly emetic. Mo rphine provided poor sedation and analgesia, delayed the requirement f or re-medication and was highly emetic. Nalbuphine and pethidine produ ced sedation with analgesia during recovery, a prolonged time to re-me dication and a mild emetic effect. None provided evidence, from analys is of postoperative re-medication times and analgesic consumption, of any pre-emptive analgesic effect. 5 We conclude that nalbuphine (mean dose 0.13 mg kg(-1)) and pethidine (mean dose 1.35 mg kg(-1)), given i ndividually as a single i.v. bolus during induction of anaesthesia, ar e the most efficacious analgesics for routine in-patient ENT surgery.