Time Course of Rocuronium-Induced Neuromuscular Blockade in Pediatric Patients: A Phase III, Randomized, Dose-Response Study

Background: We evaluated the time course of neuromuscular blockade (NMB) of three intubating doses of rocuronium in pediatric patients. Methods: This multicenter, randomized, assessor-blinded study included surgical patients aged 0 to 17 years. Anesthesia was induced with sevoflurane, continued until intubation, and maintained with isoflurane. Neuromuscular function was monitored by acceleromyography. Patients received a rocuronium dose of 0.45, 0.6 or 1.0 mg/kg, and intubation was attempted 60 sec later. Primary outcome variable was time from end of rocuronium administration to reappearance of the third twitch (T3). Time to onset of peak NMB was assessed. Safety assessments included monitoring adverse events. Results: A total of 207 patients were enrolled and randomized. Median times from rocuronium administration to NMB onset were <1.2 minutes in all age groups for each dose in the per-protocol population (n=175). Median time from rocuronium administration to reappearance of T3 ranged from 21 to 114 minutes overall, and was longer in the higher dose groups across age groups, and longer in neonates and infants compared with other age groups. There were no adverse events considered related to rocuronium. Conclusions: Rocuronium at intubating doses of 0.45, 0.6, or 1.0 mg/kg is effective in producing rapid-onset neuromuscular blockade with an intermediate duration of action in pediatric patients during sevoflurane induction/ isoflurane maintenance anesthesia. Longest duration of blockade occurred with the highest dose within all age groups, and in neonates and infants compared with other age groups.