Optimal Dose Of Dexmedetomidine Assisted With Analgesia For Reducing Postoperative Nausea And Vomiting In Patients Undergoing Gynecological Laparoscopic Surgery

Objective:To explore the clinical effect of different doses of dexmedetomidine assisted with sufentanil for postoperative analgesia on reducing postoperative nausea and vomiting in patients undergoing gynecological laparoscopic surgery,and to determine the optimal dose,providing a new treatment basis for the prevention of postoperative nausea and vomiting,in order to improve the accuracy of treatment and enhance recovery after surgery.Methods:A total of 240 patients,aged 18-65 years,ASA physical status I or II,scheduled for gynecological laparoscopic surgery under general anesthesia were randomly divided into three groups,80 cases in each group.All patients were treated with intravenous analgesia after operation.The analgesic formulation of group Dex1was sufentanil 2μg/kg+dexmedetomidine 1μg/kg,group Dex2 sufentanil 2μg/kg+dexmedetomidine 1.5μg/kg and group Dex3 sufentanil 2μg/kg+dexmedetomidine2μg/kg.All were diluted with normal saline to 100 ml,background infusion rate was3ml/h.After induction and maintenance of conventional anesthesia,the corresponding analgesic pump was connected according to the grouping results when sutured skin at the end of the operation.The general data of the patients were recorded,including age,body mass index,classification of ASA,smoking history,motion sickness history,PONV history,type of operation,duration of operation and anesthesia,anesthetic dosage and liquid infusion.The incidence of PONV,degree of postoperative pain and occurrence of other adverse reactions(including postoperative shivering,vertigo,agitation,somnolence,excessive sedation,respiratory depression,hypertension,hypotension,tachycardia,bradycardia)were observed within 0-6h,6-24h and 24-48h after operation.Results:Among the patients included in the study,three patients withdrew from the trial midway,six patients switched to open surgery,one was lost to follow-up,and eight patients stopped using the analgesic pump after surgery.As a result,222 patients were included in the final statistical analysis,including 74 cases(33.3%)in group Dex1,76cases(34.2%)in group Dex2 and 72 cases(32.4%)in group Dex3.There was no significant difference among the three groups in general data,including age,body mass index,classification of ASA,smoking history,motion sickness history,PONV history,type of operation,duration of operation and anesthesia,anesthetic dosage and liquid infusion(P>0.05).(1)Postoperative nausea and vomiting:During the first 6h after surgery,there were statistically significant differences in the incidence of PON(36.5%vs 18.4%vs 13.9%,?~2=11.884,P=0.002),POV(33.8%vs 15.8%vs 12.5%,?~2=11.774,P=0.002)and PONV(39.2%vs 19.7%vs 16.7%,?~2=11.66,P=0.003)among the three groups(P<0.05).The frequency of PON,POV and PONV during the first 6h after surgery were lower in groups Dex2 and Dex3 compared with the group Dex1(P<0.05)without significant difference between the two former groups(P>0.05).During 6-24h and 24-48h after surgery,there were no significant differences among the three groups in the incidence of PON,POV and PONV(P>0.05).(2)Postoperative analgesia:There was significant difference in 6h VAS pain score after surgery(3.51±1.15 vs 3.09±1.27 vs 2.22±0.94,F=24.767,P<0.05)among the three groups.The 6h VAS pain score after surgery was lower in group Dex3 compared with the groups Dex1 and Dex2(P<0.05)respectively without significant difference between the two later groups(P>0.05).There was significant difference in 24h VAS pain score after surgery(2.76±0.98 vs 2.08±0.88 vs 1.64±0.74,F=30.654,P<0.05)among the three groups.The 24h VAS pain score after surgery of group Dex2 was lower than that of group Dex1(P<0.05),and that of group Dex3 was lower than that of groups Dex1 and Dex2(P<0.05).There was no significant difference in 48h VAS pain score after surgery among the three groups(P>0.05).(3)Other postoperative adverse reactions:There were significant differences in the incidence of postoperative bradycardia(1.4%vs 6.6%vs 12.5%,?~2=7.253,P=0.019)and somnolence(2.7%vs 11.8%vs 16.7%,?~2=7.935,P=0.019)among the three groups.The frequency of postoperative bradycardia and somnolence in group Dex3 were significantly higher than those in group Dex1(P<0.05).There was no significant difference between groups Dex1 and Dex2,groups Dex2 and Dex3(P>0.05)in the frequency of postoperative bradycardia and somnolence.There were no significant differences in the incidence of hypertension,hypotension,shivering,vertigo and agitation among the three groups(P>0.05).All patients had no tachycardia,excessive sedation and respiratory depression.Conclusion:Dexmedetomidine(1.5μg/kg)assisted with sufentanil for postoperative analgesia can reduce the incidence of nausea and vomiting in the early six hours after gynecological laparoscopic surgery,at the same time,it has good analgesic effect and less adverse reactions.