Cisatracurium in different doses versus atracurium during general anesthesia for abdominal surgery

Background: Cisatracurium in clinical practice is devoid of histamine-induced cardiovascular effects. On the other hand, 2 ED 95 doses of cisatracurium (100 μg/kg) do not create satisfactory intubating conditions such as those seen with equipotent doses of atracurium. The recommended intubating dose of cisatracurium is 3 ED 95 . To understand this discrepancy better, we evaluated the potency and onset of atracurium and cisatracurium. Materials and Methods: The study designed as randomized controlled clinical trial to compare between atracurium (2ΧED 95 ) and different doses of cisatracurium (2ΧED 95 , 4ΧED 95 , 6ΧED 95 ) regarding onset time, duration of action, condition of intubation, hemodynamic effects, and sings of histamine release clinically. Sixty four patients were randomly assigned to one of four groups, the first group (group 1) received 2ΧED 95 dose of atracurium, group 2 received 2ΧED 95 dose of cisatracurium , group 3 received 4ΧED 95 dose of cisatracurium, while group 4 received 6ΧED 95 dose of cisatracurium. The Datex relaxograph (Type NMT-100-23-01, S/N: 37541) for neuromuscular monitoring was used. Results : HR, MABP was statistically significant increased post-intubation with administration of 2ΧED 95 dose of atracurium in group 1 and the same dose of cisatracurium in group 2 but 5-20 min later was not statistically significant with administration of 4ΧED 95 and 6ΧED 95 doses of cisatracurium in groups 3 and 4, respectively. Onset time was found to be significantly lower with 2ΧED 95 dose of atracurium than with the same dose of cisatracurium. At the same time, higher doses of cisatracurium (4ΧED 95 and 6ΧED 95 ) showed onset time and longer duration of action that was significantly lower than with atracurium and with lower dose of cisatracurium (2ΧED 95 ). Only 6ΧED 95 dose of cisatracurium showed statistically significant difference versus the atracurium dose with higher percentages of patients with excellent condition of intubation. 4ΧED 95 and 6ΧED 95 doses of cisatracurium were significantly better than 2ΧED 95 dose of cisatracurium. 2ΧED 95 dose of atracurium and 2ΧED 95 dose of cisatracurium were similar, while 4ΧED 95 and 6ΧED 95 doses of cisatracurium were significantly better than atracurium and 2ΧED 95 dose of cisatracurium. Conclusion: The same dose (2ΧED 95 dose) atracurium is more effective neuromuscular blocking agent than cisatracurium, while higher doses of cisatracurium 4ΧED 95 and 6ΧED 95 provide more effective, more rapid neuromuscular blocking with longer duration of action, stable hemodynamic status, and no associated signs of histamine release clinically