Comparison of time for the onset of action and intubating conditions using four times 95% effective dose of rocuronium versus vecuronium during endotracheal intubation

Background: Rapid sequence induction and tracheal intubation are an established technique in patients at risk for the aspiration of gastric contents. Increasing the dosage of rocuronium or vecuronium shortens the onset time of neuromuscular block. We compared the onset time and intubating conditions by using high doses (four times 95% effective dose) of rocuronium and vecuronium. Methods: In a prospective, randomised and double-blind study, 60 patients were randomly allocated into two groups. Group R (n = 30) patients received rocuronium 1.22 mg/kg body weight and Group V (n = 30) patients received vecuronium 0.172 mg/kg body weight. After administration of study drug, onset of neuromuscular block was assessed with train of four (TOF) stimuli until loss of twitch response (TOF-0) of adductor pollicis muscle to stimulation of ulnar nerve. Intubating conditions at the time of intubation were monitored and documented. Results: The mean onset time of action in Group-R was 70.7 ± 7.6 sec and in Group V was 162.2 ± 32.7 sec, which was statistically significant ( P < 0.001). Excellent intubating conditions were seen in 18 patients and good intubating conditions were seen in 12 patients in Group R versus 7 patients and 23 patients in Group V, which was statistically significant ( P = 0.004). Conclusions: At equipotent doses, rocuronium produces the early onset time of intubating conditions compared to vecuronium. Although rocuronium produces more number of excellent intubating conditions compared to vecuronium, both rocuronium and vecuronium produce clinically acceptable intubating conditions. Clinical Trial Registry- India (CTRI) number, CTRI/2021/12/038729.