RESUMO
OBJECTIVE: To determine the hemodynamic and pharmacodynamic effects of rapid bolus administration of cisatracurium compared with vecuronium. DESIGN: A randomized, prospective, double-blind study. SETTING: Tertiary-care university hospitals. PARTICIPANTS: Seventy-nine adult patients with diagnosed coronary artery disease (CAD). INTERVENTION: Elective coronary artery bypass graft surgery (CABG). MEASUREMENTS AND MAIN RESULTS: Patients were randomly divided into four groups. Patients received a rapid bolus of two or four times the 95% peak depression of twitch (ED95) of either cisatracurium (groups 1 and 2) or vecuronium (groups 3 and 4). Three minutes after a midazolam induction, all patients received a rapid bolus administration of either study drug. Maintenance of anesthesia was with a standardized propofol-sufentanil-oxygen anesthetic. Patients were monitored with radial and pulmonary artery catheters and electromyography. End points of the study were hemodynamic stability at induction, after bolus administration of study drugs, and after intubation; the quality of intubating conditions; drug interventions to correct hemodynamic instability; the onset, duration, and recovery of neuromuscular function; and drug cost. Mean arterial pressure (MAP) and heart rate (HR) decreased in a similar proportion in all four groups after induction while, following study drug administration, MAP and HR did not change significantly. Both cisatracurium groups required more boluses to maintain neuromuscular block, but spontaneous recovery rates were faster. Both agents, but cisatracurium to a lesser degree, showed increased duration with repeated maintenance doses. Both agents afforded good to excellent intubating conditions, but the cost of cisatracurium was significantly less. CONCLUSION: The authors conclude there is no evidence of a hemodynamic difference between the two neuromuscular blocking drugs (NMBDs). There are some clinical and cost advantages in favor of cisatracurium.