Abstract
Remifentanil pre-treatment has been reported to decrease the incidence of rocuronium injection-associated withdrawal movement. This study was designed to explore the site of action of remifentanil for reducing withdrawal response during rocuronium injection in children. Ninety-six paediatric patients were randomly assigned to three groups. After induction of anaesthesia with 5 mg/kg 2.5% thiopental sodium, 2 ml saline (placebo group) or 0.5 μg/kg remifentanil (group R), was injected intravenously 1 min before 0.6 mg/kg rocuronium. In a third group (group R'), the venous retention of 0.5 μg/kg remifentanil was maintained for 30 s followed by tourniquet release and injection of 0.6 mg/kg rocuronium. Withdrawal response was graded using a four-point scale. The incidence of withdrawal movement after rocuronium administration was 94%, 22% and 81% in the placebo, R, and R' groups, respectively. This study demonstrated that the pre-treatment effect of remifentanil for reducing rocuronium-associated withdrawal response occurs mainly through a central action.