HALOTHANE AND MORPHINE NITROUS-OXIDE ANESTHESIA IN PATIENTS UNDERGOING CORONARY-ARTERY BYPASS OPERATION - PATTERNS OF INTRA-OPERATIVE ISCHEMIA

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  • 1 January 1981
    • journal article
    • research article
    • Vol. 82  (3) , 372-382
Abstract
To examine whether the hemodynamic responses to halothane or morphine-N2O anesthesia produced different patterns of myocardial ischemia in patients undergoing myocardial revascularization, 26 patients anesthetized with N2O (50%) and halothane (0.2-1.0% end-tidal concentration) or morphine (2 mg/kg, i.v.) were studied. Systemic and coronary hemodynamics were measured and blood samples were taken to measure blood gases, O2 content and lactate and norepinephrine concentrations. Systemic blood pressure, rate-pressure product, systemic vascular resistance, cardiac output and stroke work were elevated following sternotomy in patients anesthetized with morphine; halothane obtunded these hemodynamic responses to surgical stress. Intraoperative myocardial ischemia occurred in both patient groups; 10 of 14 patients receiving halothane and 8 of 12 receiving morphine had at least 1 episode of ST-segment depression or myocardial lactate production. The difference between these groups was not statistically significant. Only patients anesthetized with morphine had a significantly elevated rate-pressure product when ischemia occurred. In this selected series of patients subjected to myocardial revascularization, 2 sustained a myocardial infarction and 4 died in the postoperative period. The incidence of these and other indices of postoperative morbidity was not related to choice of primary anesthetic, and did not differ between patients who sustained ischemia and those who did not.