The Effect Of Epidural Versus Intravenous Analgesia On The Postoperative Cardiac Events

Objectives: To investigate the relationship among the postoperative analgesia technique, stress response, and cardiac events, and the effect of combined ropivacaine and fentanyl postoperative epidural analgesia versus intravenous morphine analgesia on the stress response of mild to moderate risk geriatric patients that the ACC/AHA have described in 2002 guideline were studied.Methods: 40 patients with mild to moderate risk scheduled for elective open abdominal surgery, were randomized to two study groups: Group R (n=16) had been placed an epidural catheter in a lower thoracic segment (T8-T9/T9-T10/T10-T11) and received general combined epidural anesthesia and the epidural analgesia were began infusion 0.2% ropivacaine+fentanyl 2microgram/ml at 2-3ml/hour when the patients admitted to SICU after procedures. Group M (n=34) received only general anesthesia and began intravenous morphine analgesia at 1-1.5mg/h as background dosage after operation when they admitted to SICU after surgery. The analgesia time of two groups lasted for 48 hours. To evaluate analgesia, Price-Henry scale was used at the 6,12,24,36,48hour postoperatively to evaluate the pain intensity, and lower than 3 scale would been achieved in all patients.All patients had 3 leads ambulatory electrocardiograph (MV1,MV5,MavF) monitored after the patients admitted to the SICU for 48 hours and vital signs plus pulse oxygen saturation(SpO₂) were also monitored. The venous blood samples were collected at four separate time points, before induction, postoperative 2 hours, the first postoperative morning and the second postoperative morning, for ACTH and cortisol analyze.Results: There were no differences in age, sex, postoperative hemodynamic parameters between two groups. There were no statistics differences between two groups when the Price-Henry scale was compared.The concentration of ACTH and cortisol were similar in the 2 groups before operation,but M group were remarkably increased two hours postoperatively, reached to peak values on the first postoperative morning(P<0.05).6 myocardial ischemia,2 atrial fibrillation,2 ventricular tachycardia were detected in M group patients.There was a significant differences in the cortisol and ACTH concentration in cardiac events-positive compared to cardiac events-negative patients at two hours postoperatively and on the 1st postoperative morning (P<0.05),and a significant interaction over time were also found.Conclusion: Our study suggests that stress response could impact the incidence of postoperative cardiac events. The stress response was reduced by postoperative epidural analgesia compared with intravenous analgesia.