Comparison between cisatracurium and atracurium during general anaesthesia for abdominal surgery

Abstract

Background: Neuromuscular blockers (NMB) are very important adjuvant to general anesthesia, Atracurium (benzyl isoquinoline NMB) and cisatracurium besylate (benzyl isoquinoline NMB) are intermediate acting non-depolarizing muscle relaxants. In a prospective randomized study we had compared both drug at a dose of 2xED95 for Atracurium and 6xED95 for Cisatracurium as regard the onset of action, intubating conditions, clinical duration, hemodynamic changes, and adverse effects. Method: 60 patients, ASA I&II, 20-60 year old underwent elective abdominal surgerical procedure under general anesthesia (GA) were randomly assigned into 2 equal groups. Group A where 0.5mg/kg atracurium was given and Group C, where 0.3mg/kg cisatracurium was given. Neuromuscular monitoring was done by stimulating ulnar nerve and recording the action potential of adductor pollicis using TOF count. Standardized GA was given to all patients as follows, fentanyl 2mcg/kg, propofol 2mg/kg, followed by NMB agent of corresponding group at designated dose, patient will be ventilated till TOF count reaches 0, intubation was tried by the anaesthesiologist who was blind to the given NMB, intubation was done if the intubating condition was acceptable (excellent or good), and it was re-attempted every 30 sec if it was poor or inadequate. Anesthesia was maintained by N2O, O2 and sevoflurane to a total MAC 1, controlled ventilation was adjusted to normocarbia. Mean arterial blood pressure (MAP), heart rate, and intubating conditions were recorded. Interpretation of TOF count for the onset of action, clinical duration, recovery index was done. Results: Clinically acceptable intubating conditions were achieved after 120 sec more frequently after Cisatracurium (85%) than after atracurium (0%) and after 180 sec Cisatracurium (100%) and atracurium (80%). Cisatacurium had a significant shorter onset time than atracurium (120±30 versus 180±30sec), Atracurium had a significant shorter duration of action than cisatracurium (30±5 versus 60±5min). There were no evidences of any significant clinical cardiovascular changes in both groups. Conclusion: Cisatracurium has a rapid onset of action with good intubating conditions, atracurium has an intermediate duration of action, both are potent and safe with excellent cardiovascular stability.