Effect Of Transcutaneous Electrical Acupoint Stimulation On End-tidal Concentration Of Sevoflurane And Stress Response

Objective To study the effect of transcutaneous electrical acupoint stimulation (TEAS) on end-tidal concentration of sevoflurane,observe the changes of stress response hormones in stress reaction at the same depth of anesthesia and to discuss the clinical value of TEAS.Methods A total of 40 patients undergoing selective epigastric operations with ASAⅠ～Ⅱwere randomized into group A(20 cases) and B(20 cases).In group A,TEAS was performed and sevoflurane was inhaled during operation.In group B,only sevoflurane was inhaled and TEAS was not performed during operation.Electrical stimulation(ES) on Nei-guan,He-gu and Zu-sanli was performed for 30 min before induction of anesthesia in group A and meanwhile patients in group B were waiting for 30min in operating room.Then the same anesthesia induction was applied in the two groups: intravenous injection ofmidazolam 0.03mg/kg,fentanyl 3μg/kg,etomidate 0.3mg/ kg,and vecuronium 0.1mg/kg.Tracheal intubation was performed after muscle relaxation.Maintenance of anesthesia:In group A,TEAS was performed persistently and sevoflurane was inhaled,meanwhile remifentanil 0.15μg/(kg·min) was infused persistently during operation.In group B,only sevoflurane was inhaled and remifentanil 0.15μg/(kg·min) was infused persistently during operation.Contents of observation:BIS,end-tidal concentration of sevoflurane,end-tidal concentration of CO₂,non-invasive blood pressure,heart rate(HR),electrocardiogram were observed and the concentration of serum cortisol,blood glucose and angiotensinâ…¡were measured.Time points of observation:before TEAS(T₀),skin incision(T₁),exploratory laparotomy(T₂),30min after exploratory laparotomy(T₃),60min after exploratory laparotomy (T₄).Control of depth of anesthesia:the dose of remifentanil and BIS(40～50) were same in two groups.The same BIS index were maintained throng regulating inspiratory concentration of sevoflurane.Remifentanil 20μg was intravenously injected when the blood pressure exceeded 25%percent of basic data.Muscle relaxation was maintained through intravenously injecting vecuronium intermittently.Results 1 Patients in the two groups were not significantly different in gender,age, weight,time of operation,bleeding and BIS(P＞0.05).2 End-tidal concentration of sevoflurane was significantly difference in two groups(P＜0.01).3 MAP and HR were increased at T₁ and T₂ compared with T₀(P＜0.05)in both groups.MAP and HR were not significantly different at every time point between the two groups(P＜0.05).4 Cortisol and angiotensinâ…¡were significantly increased at T₁ and T₂ compared with T₀(P＜0.05) in both groups.Cortisol and angiotensinâ…¡were not significantly different at every time point between the two groups(P＞0.05).Blood glucose was significantly increased at T₂ and T₃ compared with T₀(F=3.4-3.6,P=0.012-0.02＜0.05) in both groups,and there were not significantly different at every time point between the two groups(P＞0.05).5 Multiple correlation analysis showed that MAP and HR were positively correlated with cortisol and angiotensinâ…¡(P＜0.05).6 The additional dosage of remifentanil was significantly difference in two groups(P＜0.01).Conclusion 1 TEAS can decrease end-tidal concentration of sevoflurane.2 TEAS combined with anesthetics has synergistic effect on general anesthesia.3 The intensity of stress response caused by operative stimulation is basically identical at the same BIS index in tow groups.4 The trend of changes in hemodynamics is basically identical with the change tendency of concentration of serum stress response hormones,which can indicate that changes of hemodynamics can probably reflect the intensity of stress response.