Propofol-fentanyl versus isoflurane-fentanyl anesthesia for coronary artery bypass grafting: effect on myocardial contractility and peripheral hemodynamics

Abstract

To avoid intraoperative awareness and postoperative respiratory depression from high-dose opioid anesthesia, propofol (P), or isoflurane (I) has been combined with moderate-dose opioid with varying results. However, the effects of both P and I on myocardial contractility and left ventricular afterload have not been completely quantified. The end-systolic pressure-diameter relationship (ESPDR) of the left ventricle (LV) is a reliable method to quantitatively assess LV contractility because it is relatively independent of changes in preload and incorporates afterload changes. The purpose of this study was to quantify the cardiodynamic effects of propofol-fentanyl (PF) anesthesia in comparison with isoflurane-fentanyl (IF) anesthesia in patients undergoing coronary artery bypass grafting (CABG). Thirty patients with normal or moderately impaired LV function (ejection fraction > or = 40% with LV end-diastolic pressure < or = 18 mmHg, no preoperative akinesia or dyskinesia) undergoing elective CABG were studied. After premedication with flunitrazepam, 2 mg orally, all patients were induced with thiopental, 1 mg/kg, fentanyl, 20 micrograms/kg, and vecuronium, 0.1 mg/kg, and were ventilated with oxygen/air (F(1)O2 0.6). Anesthesia was maintained throughout the procedure with a zero-order intravenous (IV) continuous infusion of P, 3 mg/kg/h (PF group), or with isoflurane inhalation of 0.6% (IF group), supplemented by intermittent boluses (5 micrograms/kg) of fentanyl (up to a total maintenance dose of 30 micrograms/kg). After intubation, a cross-section of the LV was visualized by two-dimensional transesophageal echocardiography and an m-mode echocardiogram was obtained at the maximum anterior-posterior diameter. The radial artery pressure tracing and the ECG were simultaneously recorded with the M mode.(ABSTRACT TRUNCATED AT 250 WORDS)