Butorphanol: an opioid for day-care paediatric surgery.

The purpose of this study was to compare the side effects and efficacy of equianalgesic doses of morphine (M) and butorphanol (B) in children undergoing similar surgical procedures associated with moderate postoperative pain. We studied 156 healthy children aged 1.5-13 yr who underwent elective inguinal herniorrhaphy or orchidopexy. After induction of anaesthesia subjects were given 150 micrograms.kg-1 M or 30 micrograms.kg-1 B following a randomized, stratified, blocked and double-blind design. A standardized anaesthetic was administered, which included 1.5% halothane, vecuronium, droperidol and mechanical ventilation. The postsurgical four-hour follow-up included assessment of pain, vomiting and respiratory depression. Pain was assessed with mCHEOPS and analgesics were administered when indicated in the recovery room. Each opioid was administered to a group of 78 patients. Within each group, 25 subjects had an iv induction, 21 children had an orchidopexy and 57 had inguinal hernia repairs. The groups were similar with respect to age, weight, and length of surgery. The choice of opioid did not affect recovery times from anaesthesia. Analgesic requirements were similar among the groups. Ten minutes after arrival in the recovery room the B-subjects had a lower pain score than the M-patients. Postoperative vomiting was less among the B-subjects: 14% vs 28%, P = 0.03. Two M-patients required an unscheduled admission to hospital because of vomiting. It is concluded that butorphanol has few advantages over morphine in the population studied.