Comparison of effects of atracurium and vecuronium in cardiac surgical patients.

To compare the cardiovascular effects of intubating doses of atracurium besylate and vecuronium bromide in cardiac surgical patients while utilizing fentanyl anesthesia, 20 patients scheduled for elective coronary artery bypass surgery were randomly assigned to two equal groups in a double-blind fashion. Two minutes after induction of anesthesia, baseline hemodynamic measurements were obtained and either atracurium 0.5 mg/kg (group 1) or vecuronium 0.12 mg/kg (group 2) was administered as an intravenous bolus. Hemodynamic measurements were then repeated 2, 5, and 10 minutes after injection. Atracurium produced a statistically significant decrease in blood pressure at 2 minutes and a statistically significant increase in cardiac output and decrease in systemic vascular resistance at 2, 5, and 10 minutes. Vecuronium produced no statistically significant changes in any hemodynamic variable measured other than a decrease in pulmonary capillary wedge pressure 10 minutes after the drug was administered. The hemodynamic changes seen with atracurium were closely related to changes in serum histamine levels, whereas histamine level did not change after vecuronium. There were no statistically significant differences between the two groups, even though after atracurium statistically significant changes were observed while there were no statistically significant changes associated with vecuronium. It is concluded that when utilizing the above clinical dose range, use of vecuronium may be advantageous over use of atracurium when hemodynamic stability is crucial in the anesthetic management of cardiac surgical patients.