Effect Of General Anesthesia Combined With Epidural Block Anesthesia On Stress Responses In Patients Undergoing Thoracic Surgery

Objective: To evaluate the efficacy of general anesthesia combined with epidural block Anesthesia on the plasma contents of cortisone , angiotension (AI-II) , BS and hemodynamics in patients undergoing thoracic surgery Methods Forty patients , ASA physical status I or II,undergoing elective thoracic surgery, were randomly assigned into two groups with 20 cases each: group GA, general anesthesia ; group GA+EA ,general anesthesia combined with thoracic epidural anesthesia . All the patients in various groups were premeditated with sodium luminal and scopolamine. The patients in group GA+EA were punctured into epidural space though T6-7 or T7-8 with 1% lidocaine and 0.25% bupivacaine , The anesthesia plan was under T4 level. For the induction of anesthesia, midazolam 0.1 mg·kg-1,fentanyl 4μg·kg -1, Etomidate 0.3 mg·kg -I ,Scoline 1 mg·kg–I and vecuronium 0.1 mg·kg–I were administered. General anesthesia was maintained with intravenous Propofol , Fentanyl and vecuronium. ECG,SBP, DBP,MAP ,HR and SpO2 were monitored. The venous blood samples were obtained at the following time points of before anesthesia (T0), after 5min intubation(T1), at 5min(T2) and 60min(T3) after incision and after extubation(T4) to measure the plasma contents of cortisone , angiotension (AII) and BS by radioimmunoassay and colorimetric assay, respectively.The revival time , the tracheal e xtubation time and the duration of surgery and anesthesia were monitored. The consumption of fentanyl, propofol and vecuronium in each group was recorded and compared. Results: The patients in the GA group and GA+EA group were similar in age, weight, high and type of surgical procedures.There were no differences between the two groups in duration of surgery and anesthesia verage. 1) In GA group , MAP, HR fluctuated obviously, hemodynamics were unstable. In grunp GA+EA there are not significant changes at MAP, HR during surgery, hemodynamics were stabilized respectively. There were no significant differences between two groups in heart rate. ; 2)with the basal values, the plasma glucose level were significantly increased at T3, T4 time in GA group . the level of plasma glucose in group GA+EA at time T3,T4 was higher than the level before anesthesia ( P<0.05),the level of plasma glucose in group GA at time T1,T2 and T4 was higher than that in group GA+EA( P<0.05);3)The average level of plasma cortisol in the two groups at various time was significantly lower than the levels at time T0 (P< 0.05) ,there was no significant difference in both groups at various time(P>0.05); 4)The average level of plasma Ag-II in group GA at time T1,T2,T3 and T4 was significantly higher than that of in group GA+EA (P<0.05);.3) The doses of propofol, vecuronium in group GA are greater statistically high than those in group GA+EA...