Low-dose butorphanol alleviates remifetanil-induced hyperalgesia in patients undergoing laparoscopic cholecystectomy.

OBJECTIVE: To evaluate the effects of low-dose butorphanol on hyperalgesia induced by high-dose remifetanil in patients undergoing laparoscopic cholecystectomy.

DESIGN: Randomized double-blind clinical trial.

SETTING: Intraoperative.

PATIENTS: Seventy-five patients scheduled for laparoscopic cholecystectomy were enrolled.

INTERVENTIONS: Randomly 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).

MEASUREMENTS: The visual analog scale scores and cumulative consumption of fentanyl were recorded.

MAIN RESULTS: Visual 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).

CONCLUSIONS: A high dose of remifentanil induces postoperative hyperalgesia, which could be prevented by a continuous intravenous administration of a low dose of butorphanol.