Effects Of Lidocaine Combined With Dexmedetomidine On Postoperative Nausea And Vomiting In Patients Under General Anesthesia For Thyroid Surgery

Objective:To investigate the effects of lidocaine combined with dexmedetomidine on postoperative nausea and vomiting in patients under general anesthesia for thyroid surgery.Method:One hundred and twenty ASA I^II female patients aged 20⁶0years,with BMI 18³0kg/m²under selective general anesthesia for radical thyroidectomy were included in the study.We used the random number table method to divide the patients into four groups:groups N,L,D,and LD,30 cases in each group,Lidocaine group?group L?:intravenous infusion the load dose of lidocaine 1mg/kg,which was maintained for 15 minutes before the induction of anesthesia,and intravenous infusion the maintenance dose of lidocaine 1mg·kg^-1·h^-1,which was maintained for preparing to suture the incision.Dexmedetomidine group?group D?:intravenous infusion the load dose of dexmedetomidine 0.5?g/kg,which was maintained for 15minutes before induction of anesthesia,and intravenous infusion the maintenance dose of dexmedetomidine 0.4?g·kg^-1·h^-1,which was maintained for preparing to suture the incision.Lidocaine and dexmedetomidine group?group LD?:simultaneous intravenous infusion the lidocaine and dexmedetomidine under the same conditions.Normal saline group?group N?:contrasted with the equivalent saline under the same conditions.The occurrence of nausea and vomiting at 0-2h?T₁??2-6h?T₂??6-12h?T₃?and 12-24h?T₄?and the degree of nausea and vomiting within 24 h after operation were recorded.The Visual Analogue Scale?VAS?values in resting period at2h?4h?8h?24h and 48h after operation were recorded.The perioperative adverse events?hypotension?sinus bradycardia?blurred vision and Itch of skin?were recorded.Results:The number of people of nausea at T₁,T₂,T₃,and T4 after the surgery in group LD were markedly lower than the other three groups?P<0.05?,and the number of people of vomiting at T₁,T₂,and T₃ after the surgery in group LD were markedly lower than the other three groups?P<0.05?.The number of people of nausea at T₁and T₂ after the surgery in group D were lower than the group L?P<0.05?,and the group L and group D had no evidently distinction in the number of people of vomiting?P>0.05?.The degrees of nausea and vomiting within 24 hour after the surgery in group LD were markedly lower than the other three groups?P<0.05?,and the group L and group D had no evidently distinction in the degrees of nausea and vomiting within 24 hour?P>0.05?.The resting VAS scores at 2,4,8,and 24 hours after the surgery in group LD were markedly lower than the other three groups?P<0.05?,and the group L and group D had no evidently distinction in the resting VAS scores?P>0.05?.The incidence of hypotension and sinus bradycardia in group LD were markedly higher than the other three groups?P<0.05?,and the incidence of blurred vision and Itch of skin in group LD were not statistically significant compared with the other three groups?P>0.05?.Conclusion:Intravenous infusion of Lidocaine combined with dexmedetomidine during perioperative period ceffectively relieved postoperative nausea and vomiting in patients undergoing radical thyroidectomyand,which also reduced postoperative pain score and enhanced the effect of postoperative analgesic.The effect of lidocaine combined with dexmedetomidine was better than that of lidocaine or dexmedetomidine.But the adverse events during surgery increased.