High dose fentanyl anaesthesia with oxygen for aorto-coronary bypass surgery

Abstract

Ten patients were anaesthetized with 100 per cent oxygen and fentanyl l00 μg · kg-1 for aorto-coronary bypass surgery and studied during induction of anaesthesia and initial surgical stimulation. All patients were taking propranolol and nitrates preoperatively. The patients were pre-medicated with diazepam 0.15mg·kg-1 by mouth and morphine 0.15mg·kg-1 and scopolamine 0.4 mg intramuscularly. Intravenous, arterial and Swan-Ganz catheters were inserted under local anaesthesia, after which control measurements were taken of heart rate, systolic blood pressure, pulmonary capillary wedge pressure, stroke index, cardiac index, left ventricular stroke work index, systemic vascular resistance, rate pressure product, triple index, Pao2 and Paco2. Observations were repeated after fentanyl 50 μg·kg-1 and pancuronium 0.1mg·kg-1, tracheal intubation, a further 50 μg · kg-1 of fentanyl, skin incision and sternotomy. No significant changes from control values were seen in heart rate, central venous pressure or systemic vascular resistance. Systolic blood pressure and left ventricular stroke work index decreased significantly after fentanyl 50 μg·kg-1 left ventricular stroke work index staying below control for the remainder of the study. Pulmonary capillary wedge pressure, triple index and Paco2 decreased significantly after fentanyl 100 μg·kg-1 skin incision and sternotomy. Significant decreases were noted in rate pressure product after skin incision, stroke index after sternotomy and cardiac index after both skin incision and sternotomy. Oxygen and fentanyl l00 μg·kg-1 provided stable indices of myocardial oxygen demand during induction, tracheal intubation and initial surgical stimulation in patients undergoing aorto-coronary bypass surgery. © 1981 Canadian Anesthesiologists.