ObjectiveTo evaluate the effects of low-dose butorphanol on hyperalgesia induced by high-dose remifetanil in patients undergoing laparoscopic cholecystectomy. DesignRandomized double-blind clinical trial. SettingIntraoperative. PatientsSeventy-five patients scheduled for laparoscopic cholecystectomy were enrolled. InterventionsRandomly allocated into 3 groups, low dose of remifentanil (LR) group and high dose of remifentanil (HR) group received low (0.1μg kg−1 min−1) or high (0.3μg kg−1 min−1) doses of remifentanil, respectively, and butorphanol combined with remifentanil (BR) group received remifentanil (0.3μg kg−1 min−1) and butorphanol (0.2μg/kg). MeasurementsThe visual analog scale scores and cumulative consumption of fentanyl were recorded. Main resultsVisual analog scale scores were significantly higher in the HR group than in the LR and BR groups (P<.001). The dose of intravenously given fentanyl was significantly higher in the HR group than in the LR and BR groups (P<.001). In addition, the HR group showed a significantly higher cumulative consumption of fentanyl during 5 to 8 hours after the operation (P<.001). ConclusionsA high dose of remifentanil induces postoperative hyperalgesia, which could be prevented by a continuous intravenous administration of a low dose of butorphanol.