HEMODYNAMIC AND PHARMACODYNAMIC COMPARISON OF DOXACURIUM AND PIPECURONIUM WITH PANCURONIUM DURING INDUCTION OF CARDIAC ANESTHESIA - DOES THE BENEFIT JUSTIFY THE COST

We compared the pharmacodynamic effects and hospital costs of three lo ng-acting neuromuscular blocking drugs in a prospective, randomized, d ouble-blind manner. Each neuromuscular blocking drug was administered with fentanyl (50 mug/kg) for intravenous induction of anesthesia for coronary artery bypass surgery. Each patient received twice the 95% ef fective dose (ED95) of either pancuronium (0.14 mg/kg, n = 10), pipecu ronium (0.10 mg/kg, n = 10), or doxacurium (0.05 mg/kg, n = 10). Hemod ynamic measurements were recorded at baseline, 5 min after completion of anesthetic induction, immediately after endotracheal intubation, an d 5 min after intubation. Only small hemodynamic differences between n euromuscular blocking drugs were observed. Doxacurium (but not pancuro nium or pipecuronium) significantly decreased mean arterial blood pres sure (from 94 +/- 4 mm Hg before induction to 83 +/- 3 mm Hg 5 min aft er intubation); nevertheless, there were no significant between-group differences at any time. Pancuronium increased heart rate (from 68 +/- 4 beats/min before induction to 76 +/-5 beats/min 5 min after intubat ion); however, pancuronium differed significantly from doxacurium and pipecuronium only 5 min after induction and 5 min after intubation. Ce ntral venous pressure, pulmonary artery occlusion pressure, cardiac in dex, and systemic and pulmonary vascular resistance indices did not ch ange. Electrocardiographic abnormalities were observed in two pipecuro nium patients: ST segment depression in one and premature ventricular contractions in another. No other electrocardiographic changes were ob served. There were no significant between-group differences in the nee d for hemodynamic interventions. The time from muscle relaxant adminis tration to 95% twitch depression was significantly longer for doxacuri um (530 +/- 49 s) than for either pancuronium (264 +/-31 s) or pipecur onium (234 +/- 23 s). The cost to a 70-kg patient of twice the ED95 do se was: pancuronium, $1.69; pipecuronium, $22.88; and doxacurium, $19. 60. We conclude that whereas doxacurium and pipecuronium may be less l ikely than pancuronium to increase heart rate during induction of anes thesia, these two neuromuscular blocking drugs are no less likely to p roduce hemodynamic aberrations requiring drug interventions and are co nsiderably more expensive.