Sevoflurane or halothane with target-controlled sufentanil infusions for coronary artery bypass surgery

Abstract

Objectives: Comparison of hemodynamics, circulatory efficiency, myocardial ischemia and recall during and after sevoflurane or halothane (0.6 MAC {Minimum Alveolar Concentration} inspired) combined with a target-controlled sufentanil infusion (2 ng.ml-1) for coronary artery bypass grafting. Methods: Prospective randomised non-blinded study in a university teaching hospital of 45 patients undergoing on-pump surgery. Inhalation anesthetic agent was delivered before, during and after cardiopulmonary bypass. Results: Intraoperative hemodynamics were maintained within predetermined limits using vasoactive and cardioactive drugs. Heart rate was unchanged from baseline, however the sevoflurane-sufentanil group required more glycopyrrollate, indicating a tendency towards a slower heart rate. In both groups, similar low incidences of myocardial ischemia were detected. After induction of anesthesia, as well as intraoperatively, oxygen consumption decreased by up to 36.6% compared with the awake values in both groups. Oxygen delivery remained unchanged during all measuring periods. Mixed venous oxygen tensions rose after induction, even in patients with cardiac indices below 2.2 L.min-1.m-2, indicating maintenance of an effective circulation when utilising these techniques. Twelve hours postoperatively, oxygen consumption exceeded awake values by 31%. No explicit recall was reported by any patient on enquiry on the third postoperative day. Conclusions: Low concentrations of sevoflurane or halothane, supplementing target-controlled sufentanil infusions, were both suitable for providing anesthesia for coronary bypass surgery.

Keywords: Coronary artery bypass grafting, anesthesia, hemodynamics, sevoflurane, halothane, sufentanil, mixed venous oxygen tension, oxygen consumption, balanced anesthesia