Comparison of sufentanil-oxygen and fentanyl-oxygen anesthesia for mitral and aortic valvular surgery

The cardiovascular responses, speed of anesthetic induction, incidence of chest wall rigidity, need for anesthetic supplements (phentolamine, N20, and nitroprusside) to control intraoperative hypertension, and speed of postoperative recovery were measured and compared in 44 patients undergoing aortic and mitral valvular replacement with fentanyl O₂ or sufentanil-O₂ anesthesia. After a lorazepamatropine premedication and pancuronium pretreatment, fentanyl was administered intravenously at a rate of 400 jig/min and sufentanil at 200 μg/min until patients were unconscious; at this time they were given succinylcholine and their tracheas were intubated. After intubation, an amount of fentanyl or sufentanil equal to the dose producing unconsciousness was infused over the next 30 minutes, at which time the operation began. Additional fentanyl or sufentanil was given whenever systolic arterial blood pressure (SBP) increased more than 15% over preanesthetic values. When three successive supplemental doses of the narcotic failed to effectively decrease SBP, phentolamine was used to control pressure before and during bypass; after bypass, N20 (25% to 50%) or, if N20 was ineffective, nitroprusside was used. Average time of induction was 3.4 ± 0.3 for fentanyl and 1.0 ± 0.2 min (mean ± SD) for sufentanil. Chest wall rigidity occurred in 36% of patients in both groups. Total doses of fentanyl and sufentanil required for the entire operation were 113 ± 11 and 9.0 ± 0.4 μg/kg (mean ± SD), respectively. Heart rate, cardiac output, and mean right atrial pressure remained unchanged throughout the study in both groups. Mean arterial blood pressure (MBP) and SBP were significantly decreased during induction and after intubation in patients receiving sufentanil, but not fentanyl. Arterial pressure returned to control values prior to incision in patients receiving sufentanil. Neither group experienced a significant change in SBP after incision, sternotomy, or sternal spread. However, phentolamine was required in 32% and 68% of patients receiving fentanyl before and during bypass, respectively, but in 0% to 5% of those having sufentanil. Thirty-two percent of fentanyl patients required N₂0, and 23% nitroprusside after bypass for blood pressure control. Fourteen percent of patients receiving sufentanil required N₂0, and only 5% needed nitroprusside after bypass. The results of this study demonstrate that anesthetic doses of sufentanil result in less need for supplements and vasodilators during operation, but produce more hypotension during induction than fentanyl in patients having valve replacement.