Continuous infusion of butorphanol combined with intravenous morphine patient-controlled analgesia after total abdominal hysterectomy: a randomized, double-blind controlled trial

Background and objective Postoperative pain therapy is still a problem for clinicians. Continuous basal infusion of drugs combined with standard patient-controlled analgesia (PCA) is considered to be an effective means of postoperative acute pain management. This study was designed to investigate the analgesic efficacy, morphine-sparing effects and side effects of butorphanol delivered as a continuous infusion adjunct to intravenous morphine PCA after abdominal hysterectomy. Methods One hundred and eighty-six ASA physical status I-II patients, undergoing total abdominal hysterectomy, were allocated to this randomized double-blind controlled study and assigned to one of two groups. In the butorphanol (n = 96) group, patients received an intravenous loading dose of 10 mu g kg(-1) butorphanol followed by infusion of 2 mu g kg(-1) h(-1) butorphanol combined with intravenous PCA set at a bolus of 0.02 mg kg(-1) morphine after surgery. The control group (n = 90) received a physiological saline infusion combined with the same morphine PCA. Pain intensity on movement and at rest sedation, satisfaction with analgesia, morphine consumption and side effects were recorded. Results A total of 164 patients completed the study. The butorphanol group had analgesia superior to the physiological saline control (P<0.001). The butorphanol infusion group produced higher sedation ratings (P<0.001) and better satisfaction (P<0.05) and a lower incidence of side effects (P<0.001) with the exception of sweating and dry mouth (P<0.05) than the physiological saline group. The butorphanol group consumed less morphine over 48 h, 24.6 mg (95% confidence interval, 18.7-46.6), than the physiological saline group, 58.5 mg (95% confidence interval, 41.5-79.2; P = 0.006). There were no differences between urinary catheterization of more than 24 h, first time out of bed and time to discharge to home. Conclusion Basal infusion of butorphanol combined with intravenous morphine PCA in patients undergoing abdominal hysterectomy shows effective analgesia with sedation and fewer side effects. Eur J Anaesthesiol 26:28-34 (c) 2009 European Society of Anaesthesiology.