Optimal rocuronium dose for intubation during inhalation induction with sevoflurane in children

Background. We studied 120 children aged 2–7 yr in a prospective,randomized, assessor-blinded fashion to define the optimal rocuroniumdose which provides a 95% probability of acceptable intubationconditions (ED_95TI) during inhalation induction with sevoflurane. Methods. After inhalation induction with 8% sevoflurane in 60%nitrous oxide and 40% oxygen, and loss of the eyelash reflex,we administered rocuronium (0.1, 0.15, 0.22, 0.3, or 0.6 mgkg^–1) or placebo. We quantified neuromuscular functionby stimulation of the ulnar nerve at 0.1 Hz to produce contractionof the adductor pollicis muscle using accelerometry. Intubationconditions were assessed 2 min after test drug injection. Theoptimal rocuronium dose was defined as the lowest dose, whichallowed acceptable intubation conditions in 95% of children(ED_95TI). Results. Two minutes after injection of placebo or rocuronium,intubation conditions were acceptable in 35, 45, 80, 90, 95,and 100% of children, respectively. Rocuronium 0.07 [CI 0.02–0.11],0.24 [0.19–0.31], and 0.29 [0.23–0.38] mg kg^–1provided 50, 90, and 95% probability of acceptable intubatingconditions. When thumb acceleration was depressed by 50% ormore, intubating conditions were considered acceptable in 97%of children. Recovery of the train-of-four ratio to 0.8 averaged12 (7), 16 (7), 24 (7), 24 (8), and 50 (22) min after the respectivedose of rocuronium. Conclusions. During inhalation induction with 8% sevofluranein 60% nitrous oxide, rocuronium 0.29 mg kg^–1 (ED₉₅) optimizesintubation conditions for surgery of short duration. Br J Anaesth 2002; 89: 277–81