Clinical Research Of Preventive Effect Of Parecoxib On Remifentanil-Induced Postoperative Hyperalgesia

Objective To investigate the safety and the efficacy of preventive effect of parecoxib on remifentanil-induced postoperative hyperalgesia.Methods 80 ASAⅠorⅡpatients of aged 18-65yr undergoing elective laparosopic cholecystectomy or laparosopic hernia operation were divided into 4 groups randomly(n=20each):They were small-dose remifentanil group (group S), large-dose remifentanil group (group L) , small-dose remifentanil+parecoxib group (group SP), and large-dose remifentanil+ parecoxib group (group LP). Patients in group S and group SP receive intraoperative remifentanil at 0.05μg.kg^-1·min^-1;patients in group L and group LP receive intraoperative remifentanil at 0.3μg.kg^-1·min^-1; in group SP and group LP, parecoxib 40 mg was injected intravenously 30min before the anesthesia induction. In all groups,anesthesia was maintained with remifentanil in combination with sevoflurane. 1.5 mg.kg^-1 tramadol was provided for all the groups by intravenous drip if the patients still felt pain. The time of awakening and extubation, The incisional number rating scale (NRS) at rest and in moving and sedation score at 0.5 hours, 1 hours, 2 hours, 4 hours,6 hours,12 hour and 24 hour after surgery,The number of patients who required tramadol for additional analgesia and the side effects within 24h after operation were observed and recorded. Results The patient characteristics were similar(P>0.05). The time of awakening and extubation were similar in all groups(P>0.05).The NRS scores within 2h after operation in group L were higher than in group S during the rest and moving(P<0.05),the NRS scores within 6h after operation in group SP and group LP were lower than in group S during the rest and moving(P<0.05), the NRS scores in group L,SP and LP showed no significant difference at other time points compared with group S during the rest and moving (P>0.05). More patients in group L required additional tramadol analgesia within 24h after operation than those in group S(P<0.05), the number of patients who required tramadol for additional analgesia within 24h after operation in group SP and LP showed no significant difference compared with group S(P>0.05).There were no significant differences in the NRS scores and the number of patients who required additional analgesic administration after operation between group SP and group LP (P>0.05). The Ramsay sedation score showed no significant difference among four groups(P>0.05). The incidence of shivering was significantly higher in groups L than in groups S and SP(P<0.05),There was no significant difference in other side effects among four groups (P>0.05).Conclusions Postoperative secondary hyperalgesia was induced by high dose(0.3μg·kg^-1·min^-1) of remifentanil-based anaesthesia during sevoflurane anaesthisia, it was effective that intravenous injection of parecixib 40mg before the anesthesia induction in preventing remifentanil-induced postoperative hyperalgesia without affecting recovery or increasing the side effects.