Endocrine and hemodynamic changes associated with the antagonism of fentanyl by nalbuphine have not been reported. Therefore, the authors studied ten patients after anesthetic induction with thiopental, fentanyl, trachea] intubation aided by sucdnylcholine and maintenance with diazepam, pancuronium, N2O, and further doses of fentanyl. Eight of the patients underwent cholecystectomy, one had a hysterectomy, and another had an abdominoplasty.
After reversal of neuromuscular block at the conclusion of surgery, normal ventilation was restored by 0.22 ± 0.02 mg/kg intravenous nalbuphine (mean ± SEM). Plasma levels of free norepinephrine, histamine, and cortisol did not increase after antagonism of the fentarnyl-induced respiratory depression, but plasma coticentration of epinephrine increased significantly but without significant hemodynamic changes. Minute ventilation was 1.5 ± 0.4 L/min before and 11 ± 1, 10 ± 1, 11 ± 1, and 10 ± 1 L/min at 15, 30, 45, and 60 min after antagonism; corresponding PaCO2 levels were 56 ± 2, 44 ± 1, 49 ± 7, 49 ± 1, 42 ± 1 mm Hg. The mean analogue pain score remained below 1.5. We conclude that nalbuphine effectively antagonizes fentanyl-induced respiratory depression without adverse endocrine and circulatory changes or loss of analgesia.
Address correspondence to Dr. Zsigmond, Department of Anesthesiology, University of Illinois, 1740 West Taylor Street, Chicago, IL 60612
© 1987 International Anesthesia Research Society