THE EFFECTS OF ANESTHETIC TECHNIQUE ON THE HEMODYNAMIC-RESPONSE AND RECOVERY PROFILE IN CORONARY REVASCULARIZATION PATIENTS

This study was undertaken to assess the effects of propofol (versus enflurane, fentanyl, and thiopental) on hemodynamic stability and recovery characteristics when used for maintenance of anesthesia during elective coronary artery bypass grafting (CABG) procedures. Ninety premedicated patients scheduled for elective coronary revascularization had anesthesia induced with fentanyl 25 mu g/kg intrave nously N. When the mean arterial blood pressure (MAP) increased 10% above preoperative baseline values, patients were randomized to receive one of four anesthetic treatments: enflurane, 0.25-2.0%; fentanyl, 10-20 mu g/kg IV bolus doses; propofol, 50-250 mu g . kg(-1). min(-1) IV or thiopental, 100-750 mu g . kg(-1). min(-1) IV. The maintenance anesthesia was titrated to achieve hemodynamic stability (i.e., maintain the MAP within 10% of the baseline values and heart rate [I-IR] within 20% of the baseline values). After bypass, anesthetic and cardiovascular drugs were titrated to maintain the MAP >65 mm Hg and the cardiac index (CD >2.3 L . min(-1). m(-2). Recovery was assessed by noting the times at which patients first opened their eyes, responded to verbal communication, correctly responded to specific commands, underwent tracheal extubation, and were discharged from the intensive care unit (ICU). Although less intraoperative hypertension was noted in the propofol-treated patients (19 +/- 11 min vs 38 +/- 26 min, 30 +/- 24 min,and 30 +/- 23 min in the enflurane, fentanyl, and thiopental groups,respectively) (P = 0.04), the incidence of hypotension did not differ significantly among the groups. Vasopressor drugs were required more often during the prebypass period in fentanyl and propofol patients (4/22 and 5/23, respectively) compared to the thiopental group (0/21) (P < 0.05), During CPB, fentanyl-treated patients required vasoconstrictors more often than patients in the other three treatment groups (14/22 vs 6/24, 4/23, and 5/21 in the enflurane, propofol, and thiopental groups, respectively) (P < 0.01). Although fentanyl-treated patients had significantly greater requirements for inotropic support during weaning from CPB than propofol-treated patients (14/22 vs 7/23) (P < 0.038), there were no significant differences among the groups in the postbypass or ICU periods. Propofol-treated patients responded to verbal stimuli (2.1 +/- 1.3 h vs 4.0 +/- 3.5 h, 4.7 +/- 2.7 h, and 5.6 +/- 3.6 h in the enflurane, fentanyl, and thiopental groups, respectively) (P = 0.01) and followed commands earlier (propofol 7.3 +/- 5.2 h vs enflurane 12.5 +/- 5.7 h, fentanyl 13.1 +/- 6.6 hand thiopental 12.8 +/- 6.7 h) (P = 0.01). In addition, propofol-treated patients were tracheally extubated sooner than patients in either the fentanyl or the thiopental group (14 +/- 5 h vs 29 +/- 19 h and 20 +/- 4 h, respectively) (P = 0.001). Although the cost of the study drug was highest in the propofol group (propofol $46 +/- 22 vs enflurane $7 +/- 3, fentanyl $10 +/- 4,and thiopental $6 +/- 3), the ability to ''fast track'' patients receiving propofol would be expected to offset its greater cost. We conclude that shorter-acting drugs (e.g., propofol and enflurane) can facilitate an early recovery after coronary artery revascularization without compromising introperative hemodynamic stability.