Background: The aim of this study was to determine whether or not inhalation induction with sevoflurane can prevent the withdrawal movement associated with the injection of rocuronium.
Methods: A total of 75 pediatric patients were randomly allocated to five groups (S 1.5, 2.0, 2.5, 3.0, and the control group). In the control group (n=15), 2.5% thiopental 5 mg/kg was injected intravenously. Rocuronium 0.4 mg/kg was injected immediately after loss of consciousness. In the S 1.5, 2.0, 2.5, or 3.0 group, rocuronium 0.4 mg/kg was injected at 1.5, 2, 2.5, or 3 min after inhalation induction, respectively, and the withdrawal response was recorded. End-tidal sevoflurane concentrations were recorded at the time of the rocuronium injection. The inhalation time of sevoflurane before rocuronium injection required to provide no withdrawal response in 50% and 95% of patients (IT50 and IT95) was calculated.
Results: The incidence of withdrawal was 80% (12/15), 71.4% (10/14), 21% (3/14), 0% (0/14), and 0% (0/15) in group C, group S 1.5, group S 2.0, group S 2.5, and group S 3.0, respectively. IT50 of the rocuronium injection time was 1.7 min (95% CI: 1.5–1.9) and IT95 was 2.3 min (95% CI: 2.0– 2.9).
Conclusions: This study demonstrated that inhalation induction with sevoflurane can prevent the withdrawal movement induced by rocuronium in children, and IT50 and IT95 for the prevention of movement was 1.7 and 2.3 min, respectively.