Effect Of Intravenous Infusion Of Ultra-high-dose Remifentanil On Postoperative Pain

Objective:To assess the effect of intraoperative intravenous infusion of UHD remifentanil on postoperative pain in the adult patients undergoing subtotal thyroidectomy.Methods:Sixty patients(aged18-60years) under general anesthesia endotracheal intubation were randomized and received an intraoperative infusion of0.2(relative-high-dose,RHDgroup) or1.2ug/kg/min (ultra-high-dose,UHD group) remifentanil in subtotal thyroidectomy. Quantitative sensory threshold (QST)on the right forearm was assessed by Von frey filaments before surgery(baseline),postoperative2h and18-24h.VAS score was examined at15min,30min,45min,60min,90min,120min and18-24h after extubation.Morphine was administered when VAS≥4postoperatively.Cumulative morphine consumption and the adverse effects of remifentanil was recorded at the postoperative24h.Results:VAS score was lower at postoperative15min in the ultra-high-dose group than relative-high-dose group.There was no difference in VAS score between the two groups at other point in time after surgery(P>0.05).In both groups,QST in the right forearm was decreased at postoperative24hour as compared with the baseline. Postoperative morphine consumption was less in the UHD group when compared with RHD group (P<0.05) Conclusions:Intraoperative intravenous infusion of UHD remifentanil could attenuate postoperative pain. However, UHD remifentanil also led to the postoperative hyperalgesia.