A study of epidural morphine and sufentanil anesthesia for abdominal aortic surgery

Abstract

Thirty six comparable patients, ASA 2, without cardiac disease, underwent aortic disobliteration, 19 under epidural 100 micrograms/kg morphine (EM) and 17 under epidural 2 micrograms/kg sufentanil (ES), combined with general anesthesia. To compare the hemodynamics, measurements were taken pre-operatively, after induction of general anesthesia, during aortic dissection, aortic cross-clamping and 3-5 minutes after the first revascularisation. Plasma and CSF drug levels were measured at intervals in 6 patients in the EM end 5 patients in the ES group. Both drugs provided satisfactory analgesia which persisted for 10.4 hours in the EM and 6.3 hours in the ES group. The fall in systemic pressure and left ventricular work in both groups after induction of general anesthesia suggests that EM and ES must be used with caution in patients with hypovolemic or cardiovascular disease. There was a significant difference in SVR between the two groups during the aortic dissection, due to a rise in SBP in the ES group and a tendency for SVR to fall in the EM group. However significant differences in left ventricular work did not occur. Notable was the absence of significant changes in filling pressure, CI and left ventricular function during aortic cross-clamping. After revascularization a significant decrease in systolic blood pressure occurred in association with an increase in heart rate in the EM group. The influence of the plasma and CSF concentrations of morphine and sufentanil on the hemodynamic changes during surgery were evaluated.