Effects Of Dexmedetomidine Combined With Ropivacaine On Postoperative Nausea,Vomiting And Pain In Patients Undergoing Temporomandibular Joint Surgery

Objective:To investigate the effect of dexmedetomidine combined with ropivacaine on postoperative nausea,vomiting（PONV）and pain in adult female patients undergoing temporomandibular joint surgery.Methods:A total of 75 female patients who underwent temporomandibular joint surgery were included in Shenzhen Stomatological Hospital from 2021 January to 2022 January.They were randomly divided into the study group（38 cases）and control group（37 cases）.After general anesthesia intubation,20 m L 0.5%ropivacaine+2.0μg/kg dexmedetomidine were used in the study group,and 5%ropivacaine+normal saline were used in the control group for local infiltration anesthesia in the operation area.The main outcome measures of the two groups were recorded:The incidence and frequency of PONV.The secondary outcome indicators included postoperative pain score（VAS）at4h,8h,24h and 48h,effective pressing times of analgesic pump,data of mean arterial pressure（MAP）and heart rate（HR）at the corresponding time points during the operation,before anesthesia induction（T₁）,at the beginning of the operation（T₂）,and at the end of the operation（T₃）.Statistical analysis was conducted using.Results:1.PONV:The incidence of PONV in the study group（13.2%）was lower than that in the control group（40.5%）,（P<0.05）;The frequency of vomiting in the study group was 1（1,1）which lower than 3（1.5,5）that in the control group,which was statistically significant（P<0.05）.2.Postoperative pain:The VAS scores at 4h,8h and 24h after operation in the study group were 2（1.25,3）,2（2,3）and 2（1,2）respectively,which were lower than those in the control group 3（3,4）,5（4,5）and 3（1,3）.The differences were statistically significant（P<0.05）.The 48h VAS scores of the study group and the control group were 1（0,1）and1（1,1）,which were no significant difference（P>0.05）.There was no statistically significant difference in VAS scores within the study group,except for the comparison at4 and 8 hours,as well as the comparison at 24 and 48 hours（P>0.05）.The other pairwise comparisons showed statistical differences（P<0.05）;There was no statistically significant difference（P>0.05）between the control group at 4 hours and 24 hours,4 hours and 48hours,and 24 hours and 48 hours,while there was a statistically significant difference（P<0.05）between the other two groups.The pressing times of the study group 2（1,3）times were significantly lower than those of the control group 9（8,10）times,which was statistically significant（P<0.05）.Single factor analysis showed that the effective number of compressions for patients with vomiting was 8（6,9.25）,which was higher than the effective number of compressions for patients without vomiting by 4（2,8）,with a statistically significant difference（P<0.05）.In the correlation analysis between vomiting frequency and effective compression frequency,r=0.289,95%CI=0.060 to 0.490,P=0.012,and the difference was statistically significant（P<0.05）.3.Data of MAP and HR at corresponding time points:There was no statistically significant difference in MAP and HR between the two groups at T₁-T₃（P>0.05）.Conclusions:Dexmedetomidine combined with ropivacaine for local infiltration anesthesia in adult female patients undergoing temporomandibular joint surgery can reduce the incidence of PONV,improve the postoperative analgesic effect and prolonged analgesic effect.The method is feasible and convenient,which is worthy of clinical promotion.