Rocuronium versus cisatracurium: onset of action, intubating conditions, efficacy, and safety

Neuromuscuiar blockers [NMB] are very important adjuvant to general anesthesia. Rocuronium bromide [ammosteroidal NMB] and cisatracunum besylate [benzyl isoquinolme NMB] are recently introduced non-depolarizing muscle relaxants In a prospective randomized study we had compared both drug at a dose 2x [ED95] as regard the onset of action, intubating conditions, clinical duration, hemodynamic changes, and adverse effects 40 female patients ASA l and ll. 20-50 year old underwent elective gynecological ambulatory surgery under general anesthesia [GA] were randomly assigned into 2 equal groups. ROC group, where 0.6mg/kg rocuronium was given and CIS group, where 0 1mg/kg cisatracurium was given. Neuromuscuiar monitoring was done by stimulating uinar nerve and recording the action potential of the first dorsal interosseous muscle using Date x Relaxogram. Standardized GA was given to all patients as follows, fentanyl 1.5mcg/kg. propofol 2mg/kg. 2x [ED95]/kg of the examined NMB. intubation was tried by the same anesthetist who was blind to the given NMB after 60 sec of injection, 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 60% N2O in 02 and isoflurane to a total MAC 1.5. controlled ventilation was adjusted to normocarpia. Mean arterial blood pressure [MAP], heart rate, and intubating conditions were recorded interpretation of relaxogram for the onset of action, clinical duration, recovery index was done Clinically acceptable intubating conditions were achieved after 60 sec more frequently after rocuronium [80%] than after ctsatracurium[O%]. Rocuronium had a significant shorter onset time than cisatracunum [70.6 +/- 18.2 versus 160.4 +/- 14.3sec], Rocuronium had a significant shorter duration of action than cisatracurium [30.3 +/- 5.2 versus 45.7 +/- 7/5min], and the spontaneous recovery index was significantly shorter with rocuronium than cisatracurium [9.2 +/- 1.8 versus 13.6 +/- 2.4min]. There were no evidences of any significant clinical cardiovascular changes in both groups. There were no clinical signs of histamine release in both groups, but there was burning pain at the site of rocuronium injection in more than 50% of patients Conclusion: Rocuronium has a rapid onset of action with good intubating conditions, cisatracurium has an intermediate duration of action, both are potent and safe with excellent cardiovascular stability and without apparent histamine release