Preoperative butorphanol and flurbiprofen axetil therapy attenuates remifentanil-induced hyperalgesia after laparoscopic gynaecological surgery: a randomized double-blind controlled trial.

BACKGROUND

Several studies indicate that remifentanil exposure may engender opioid-induced hyperalgesia. Butorphanol and flurbiprofen axetil are proposed as adjunctive analgesics for postoperative pain control. This randomized double-blind controlled study was designed to investigate the antihyperalgesic effects of butorphanol combined with flurbiprofen axetil on opioid-induced hyperalgesia.

METHODS

One hundred and twenty patients undergoing elective laparoscopic gynaecological surgery with sevoflurane anaesthesia were randomized to one of four groups, as follows: intraoperative sufentanil 0.30 µg kg (Group S); remifentanil 0.30 µg kg min (Group R); intraoperative remifentanil and pre-anaesthesia butorphanol 20 µg kg (Group B); or intraoperative remifentanil and pre-anaesthesia butorphanol 10 µg kg combined with flurbiprofen axetil 0.5 mg kg (Group BF). Sufentanil was used to control postoperative pain. The threshold and area of postoperative mechanical hyperalgesia were measured with Von Frey filaments. Pain intensity, sufentanil consumption, and side-effects were recorded for 24 h after surgery.

RESULTS

Compared with Group S, remifentanil anaesthesia increased the pain score, postoperative sufentanil consumption, and area of hyperalgesia [mean 49.9 (sd 8.6) vs 60.5 (10.0) cm, P<0.001] and reduced the hyperalgesia threshold on the dominant inner forearm [mean 89.5 (sd 23.4) vs 60.6 (22.6) g, P=0.004]. Compared with Group R, the pain score, sufentanil consumption, and area of hyperalgesia were reduced and hyperalgesia threshold was elevated likewise in Groups B and BF. However, the efficacy in Group BF was higher than in Group B (P=0.021).

CONCLUSIONS

The preoperative combination of butorphanol and flurbiprofen axetil effectively ameliorated opioid-induced hyperalgesia in patients undergoing laparoscopic gynaecological surgery under sevoflurane-remifentanil anaesthesia.

CLINICAL TRIAL REGISTRATION

NCT02043366.