GENERAL ANAESTHESIA VERSUS LUMBAR EPIDURAL ANAESTHESIA IN LOWER ABDOMINAL AND PELVIC SURGERY OF MYOCARDIAL ISCHAEMIC PATIENTS

Abstract

Due to increased incidence of patients with myocardial ischemia undergoing major non-cardiac surgeries, the need to improve the incidence of mortality and morbidity is under many research protocols. Prevention and relief of myocardial ischemia are the aim, and are based on improving oxygen supply and reducing oxygen demand. Previous studies have derr::r_,... ••,­ that the activation of the sympathetic nervous system may result ischemia and infarction. Also interventions that inhibit the sympathetic response can reduce cardiac morbidity. The mechanisms whereby sympathetic activation causes cardiac morbidity can be mediated both by increases in myocardial oxygen demand (increase in heart rate, blood pressure and inotropy) or reductions in myocardial oxygen supply(coronary vasoconstriction or thrombosis). In patients with coronary heart disease, cardiac sympathetic block produces small reductions in cardiac output, heart rate, and blood pressure and may thus decrease myocardial oxygen demand. Also the blood flow to ischemic regions of the myocardium increases, regional distribution of myocardial blood flow improves by increasing the endocardial to epicardial blood flow ratio, and sympathetically mediated coronary constriction distal to the coronary stenosis is inhibited. The present study was done at the Suez Canal University hospital, comparing general anesthesia versus epidural anesthesia m myocardial ischemic patients undergoing lower abdominal or pelvic surgeries The patients included in the study