Effect Of Dexmedetomidine Combined With Ropivacaine Serratus Anterior Plane Block On Postoperative Analgesia In Breast Cancer Patients

Objective:To observe and evaluate the effect of dexmedetomidine assisted ropivacaine for SAPB on intraoperative stress level,postoperative analgesia and adverse reactions in patients undergoing breast cancer surgery,so as to provide reference for the application of dexmedetomidine around nerves and postoperative analgesia in patients with breast cancer.Methods:Sixty female breast cancer patients,aged 28-65 years old,with BMI of 18.5-28 kg/m2 and ASA grade I or II,who underwent elective modified radical unilateral breast cancer surgery at the China-Japan Union Hospital of Jilin University between October 2022 and January 2023 were selected.They were randomly divided into 3 groups of 20 patients each using the randomization principle.Each group was given different interventions based on general anaesthesia.Group C(control group): no preoperative regional block pretreatment,additional 0.1ug/kg sufentanil was required at the time of skin incision.group R(simple ropivacaine group): preoperative 0.375% ropivacaine 20 m L at the side of the operation for ultrasound-guided serratus anterior plane block,no additional sufentanil during the operation.group RD(ropivacaine+ dexmedetomidine Group): 20 m L of preoperative mixture of 0.375% ropivacaine and 1ug/kg dexmedetomidine was performed on the operative side with ultrasound-guided serratus anterior plane block,and no additional sufentanil was added intraoperatively.All patients were treated with the same anesthesia induction regimen,with sevoflurane and remifentanil as the main anesthesia maintenance,and PCIA was used for analgesia after operation.The following data were recorded for each group of patients,Primary indicators:(1)VAS pain scores at 2 h(T4),6 h(T5),12 h(T6),and 24 h(T7)postoperatively;Secondary indicators:(2)General information of patients: age,height,weight,and BMI.(3)Duration of surgery,duration of anesthesia,time of extubation,and intraoperative dosage of various drugs.(4)MAP and HR at each time point,before anesthesia(T0),immediately after intubation(T1),immediately after initiation of incision(T2),and immediately after catheter removal(T3).(5)Occurrence of adverse reactions.Results:The differences were not statistically significant(P>0.05)when comparing general information,operation and anesthesia time,and intraoperative vasoactive drug use;while the extubation time in RD group was significantly shorter than the other two groups,and the difference was statistically significant(P<0.05).The dosage of sufentanil in group C was the most,and the dosage of remifentanil in group RD was the least(P<0.05).Intraoperative hemodynamic changes: Comparison between groups: At T2,MAP and HR in group C were significantly lower than those in group R(P<0.05).At T3,MAP and HR in group RD were significantly lower than those in the other two groups(P<0.05).Compared with the same group,MAP in group C and group R at T3 was significantly higher than that at T0(P<0.05).HR in group C was the lowest at T2,and HR was significantly increased at T3(P<0.05).Comparison of postoperative analgesia scores: On the whole,the difference of VAS scores between different groups was statistically significant(P<0.001).With the change of time,VAS score increased first and then decreased(P<0.05).There were statistical differences in the VAS scores of the three groups at T4,T5,T6 and T7(P<0.05).The VAS score of RD group was the lowest at each time point(P<0.05).At T4 and T5,the VAS score of group C was higher than that of group R(P<0.05).Comparison of adverse reactions: three groups of patients only nausea,vomiting,dizziness,no other adverse reactions.Conclusion:For patients undergoing breast cancer surgery,dexmedetomidine combined with ropivacaine for serratus anterior plane block is better than ropivacaine serratus anterior plane block.It has the following three advantages:(1)effectively reducing the consumption of opioid analgesics during operation and shortening extubation time.(2)reducing the body’s stress response,and maintaining smooth hemodynamic changes.(3)extending the duration of postoperative analgesia and improving the postoperative analgesic effect.