A two-center comparison of the cardiovascular effects of cisatracurium (Nimbex(TM)) and vecuronium in patients with coronary artery disease

Cisatracurium (Nimbex(TM)) is an intermediate-acting benzylisoquinolinium neuromuscular blocker that is one of the stereoisomers of atracurium. It causes no clinically significant cardiovascular side effects or histamine release in doses up to 8 x ED₉₅ in healthy patients. Seventy patients undergoing elective myocardial revascularization consented to participate in an Institutional Review Board approved pilot study (10 patients) and an open- label, randomized, controlled trial comparing the hemodynamic effects of cisatracurium with vecuronium (60 patients) at two centers. The patients were anesthetized using 100% oxygen, fentanyl, and midazolam, and tracheal intubation was facilitated with succinylcholine. At least 5 min after tracheal intubation, baseline hemodynamic measurements were obtained. The patients received 0.10 mg/kg of cisatracurium (2 x ED₉₅) or 0.10 mg/kg of vecuronium (2 x ED₉₀) as follows: cisatracurium over 60 s (Pilot Group A, n = 5); cisatracurium over 30 s (Pilot Group B, n = 5); cisatracurium over 5- 10 s (Group C, n = 30); or vecuronium over 5-10 s (Group D, n = 30). The hemodynamic measurements were repeated at 2, 5, and 10 min after cisatracurium or vecuronium injection. There were no episodes of cutaneous flushing. One patient was hypotensive before and after cisatracurium administration, and was excluded from analysis. Otherwise, there were no episodes of hypotension requiring therapy in any patient after cisatracurium. Fifteen patients overall were excluded from the analysis for one or more of the following: light anesthesia, treatment for hypotension < 10 min prior to baseline, or equipment difficulties. Although there were multiple statistically significant (P < 0.05) hemodynamic changes from preinjection to postinjection, in no case were Groups C and D discordant, and no patient who received cisatracurium had a ≥20% decrease in the mean arterial pressure. The hemodynamic changes observed in the cisatracurium patients were minor (< 15% change from baseline) and indistinguishable from those observed in the patients receiving vecuronium. A rapid bolus (2 x ED₉₅) dose of cisatracurium results in small hemodynamic side effects in patients with coronary artery disease.