COMPARISON OF ISOFLURANE, HALOTHANE AND FENTANYL IN PATIENTS WITH DECREASED EJECTION FRACTION UNDERGOING CORONARY SURGERY

The aim of the study was to compare three anaesthetic agents in patien ts with ejection fraction below 0.40 subjected to coronary revasculari zation surgery. Twenty-five elective coronary surgical patients with e jection fraction below 0.40 were prospectively studied. Premedication was pethidine 1 mg/kg and induction was fentanyl 0.03 mg/kg and pancur onium 0.1 mg/kg. The patients were randomized to one of three maintena nce techniques (fentanyl, isoflurane or halothane). Radial arterial pr essure, heart rate, right atrial pressure, pulmonary arterial and occl uded pressures, and thermo-dilution cardiac output were measured, and cardiac inner and resistance calculated, at the following times: befor e induction; 5 min after intubation; 2 min after sternotomy; immediate ly after discontinuation of bypass, 15 min afterwards; immediately aft er sternal closure; during suture of the skin; 5 min after arrival in the postoperative care unit; and 60 min postoperatively. Mean arterial pressure decreased significantly in the isoflurane group and nonsigni ficantly in the halothane group after induction. Cardiac index decreas ed significantly in the isoflurane group and nonsignificantly in the h alothane group after induction and after sternotomy. Neither pressure nor flow decreased in patients receiving fentanyl. Following weaning f rom cardiopulmonary bypass, systemic vascular resistance decreased sig nificantly in all groups. Cardiac index, however did not increase abov e control values and arterial pressure consequently decreased; there w as no significant difference between groups.