Sufentanil Does Not Block Sympathetic Responses to Surgical Stimuli in Patients Having Coronary Artery Revascularization Surgery

The effects of a moderate dose of sufentanil (1 μg·kg−1 + 0.015 μg·kg−1 ·min−1) plus nitrous oxide (30% O2/70% N2O) anesthesia (group I; n = 8) and of high-dose sufentanil/O2 anesthesia (10 μg·kg−1 + 0.15 μg·kg−1·min−1) without N2O (group II; n = 8) on cardiovascular dynamics, myocardial blood flow, myocardial oxygen consumption, myocardial lactate balance, and hypo-xanthine release were studied in two groups of male patients scheduled for elective coronary artery bypass surgery. All patients were on maintenance doses of calcium channel blockers and nitrates with the last doses of medications given the morning of operation. All patients were premedicated with flunitrazepam (2 mg orally), piritramide (7.5 mg IM) and promethazine (25 mg IM). Measurements were performed before the induction of anesthesia with the patients premedicated but awake; 20 min after induction of anesthesia with sufentanil plus pancuronium 0.1 mg·kg−1 for muscle relaxation before surgery; and during sternotomy and sternal spread. Sufentanil at either dose decreased mean arterial pressure, as well as cardiac and stroke volume index while heart rate remained unchanged. Following the induction myocardial blood flow and myocardial oxygen consumption decreased 23% (79 ml·min−1 ·100 g−1 to 61 ml·min−1 ·100 g−1 and 28% (9.2 ml O2·min−1·100 g−1 to 6.6 ml O2·min−1·100 g−1) in group I and 14% (78 ml·min−1 100 g−1 to 67 ml·min−1 100 g−1 and 18% (8.7 ml O2·min−−1·100 g−1 to 7.1 ml O2·min−1·100 g−1) in group II. Myocardial ischemia was seen in one patient of group II (patient No. 4), as indicated by a hypoxanthine release into the coronary sinus, when after the induction MAP decreased from 93 to 67 mm Hg and heart rate increased from 56 to 71 min−1. During sternotomy 8 of 16 patients (56%) developed hypertension and 9 of 16 patients (56%) showed signs of myocardial ischemia, i.e., a lactate and for hypoxanthine release. Ischemia was related to hypertension in three patients but occurred in six patients without significant alterations in heart rate, PAP, PCWP, or arterial pressures. These data demonstrate that sufentanil, like fentanyl, produces incomplete anesthesia in patients with coronary heart disease and is not able to protect the myocardium adequately from autonomic sympathetic responses, even though sufentanil has the advantage of having more rapid onset of action than fentanyl.