Effects Of Transcutaneous Electrical Acupoint Stimulation On Hemodynamics And Respiratory Mechanics Among Elderly Patients In Prone Position Under General Anesthesia

Objective:By observing the effects of transcutanclus electrical acupoint stimulation（TEAS）in combination with general anaesthesia on respiratory mechanics,haemodynamics as well as stress indicators in the blood system of elderly patients undergoing surgery in the prone position,this study aims to evaluate its efficacy in stabilising circulatory and respiratory mechanics indicators in elderly patients experiencing general anaesthesia in the prone position.Methods:A total of 88 patients,including 57 males and 31 females,aged over 65 years old,were selected for elective thoracolumbar surgery with reference to Class I or II standards,as prescribed by American Society of Anesthesiologists（ASA）.All patients were randomly divided into TEAS combined with general anaesthesia group（Group E）and control group（Group C）,with 44 cases in each group.Before induction of anaesthesia,group E received TEAS treatment at bilateral Hegu acupoint,Neiguan acupoint,Xinshu acupoint and Feishu acupoint for 30 min;group C was treated with electrode pads applied to the same acupoints without electrical stimulation.Patients in both groups were anesthetized by all intravenous means,and provided with self-controlled intravenous analgesia（PCIA）after surgical operation.The basal values of heart rate（HR）,mean arterial pressure（MAP）,cardiac index（CI）and stroke volume（SV）were recorded before TEAS treatment at the following time points T₀,before induction of anaesthesia T₁,5min after tracheal intubation T₂,30 min of ventilation in prone position T₃,60 min of ventilation in prone position T₄,5 min after extubation T₅,and 30 min after extubation T₆.Additionally,intraoperative doses of anesthetic maintenance drugs,remifentanil and propofol,were recorded.Afterwards;The total amount of vasoactive drugs employed in the two groups was recorded and analyzed;3 ml of venous blood was taken from patients at T₀,T₁,T₅ and T₆to measure the concentration of cortisol（Cor）and endothelin（ET）in plasma.Specific values of peak pressure（Ppeak）,plateau pressure（Pplat）,static compliance(CT_ST)and dynamic compliance（CT_D）were recorded and analysed at T₂,T₃ and T₄.1 ml of arterial blood was taken at T₀,T₂,T₄ and T₆ for arterial blood gas analysis to record the values of oxygenation index（OI）and arterial partial pressure of carbondioxide（Pa CO₂）.Postoperative follow-up of patients was performed to summarize visual analogue scale（VAS）scores at 6h,8h,24h and 48h postoperatively for statistical analysis using SPSS22.0 software.Results:1.There was no difference in the baseline data between the two groups（P>0.05）;2.There was no statistically significant difference in MAP and HR between the time points of group E and T₀（P>0.05）;MAP and HR increased at time point T₂ and decreased at time point T₄ in group C compared with time point T₀,indicating the difference was statistically significant（P<0.05）.There was no statistically significant difference in MAP and HR compared between the two groups（P>0.05）.Compared with T0 time point,CI and SV decreased at T₃ and T₄time points in both groups（P<0.05）,CI was lower in group C than in group E at T₄ time point,and SV was lower in group C than group E at T₃ time point（P<0.05）.The total amount of intraoperative ephedrine used in group E was less than that in group C（P<0.05）;Intraoperative dosage of remifentanil injection in group E were less than that in group C,and the difference was statistically significant（P<0.05）;Through comparing with T₀ time point,the plasma concentrations of Cor and ET were significantly higher in both groups at time points T₂,T₅ and T₆（P<0.05）,the plasma concentrations of Cor were higher in group C than in group E at T₂time point（P<0.05）,and the plasma concentrations of ET were higher in group C than in group E at time points T₂and T₅（P<0.05）.3.By contrast with T₄time point,Ppeak increased at T₃and T₄ time points in group E,Pplat increased at T₄in group E,Ppeak and Pplat increased at T₃and T₄ time points.Ppeak and Pplat were higher in group C than in group E at T₃and T₄ time points（P<0.05）.Compared with T₂ time point,CT_ST and CT_D increased in group E and C at T₃and T₄.As for the comparison between the two groups,CT_STand CT_D were lower in group C than in group E at T₃ and T₄time points（P<0.05）;4.There was no statistically significant difference in Pa CO₂between the two groups（P>0.05）,and the OI at time point T₄was higher than that at T₀in both groups（P<0.05）;5.There was no significant difference in VAS scores between the two groups at each time point after operation（P>0.05）.