Optimal clinical dose of rocuronium bromide for laryngeal mask airway insertion during sevoflurane anesthesia in children

Abstract

Background: The median effective dose, ED50, of rocuronium bromide for inserting the laryngeal mask airway (LMA) in children was not known. The purpose of this study was to determine the clinical ED50 (cED50：median value of rocuronium dose of 6 set of crossing success and failure by Dixon’s up-and-down method) of rocuronium to insert a LMA in pediatric patients. Methods: Children aged 2 to 12 years (n = 21) and scheduled for urologic, orthopedic, plastic or ophthalmic surgery lasting less than 2 hr under general anesthesia were enrolled in this study. After applying a standard cardiorespiratory monitor, all patients received thiopental sodium 5 mg/kg for induction of anesthesia. Insertion of LMA was attempted 90 seconds after administration of rocuronium and manual ventilation with 8 vol% of sevoflurane. We recorded the movement of patients, blood pressure and heart rate. The initial dose of rocuronium was 0.3 mg/kg, and in accordance with Dixon’s up-and-down method, the rocuronium concentration for consecutive patients in each patient was varied with increments or decrements of 0.05 mg/kg based on the result of previous patient. Results: The cED50 of rocuronium required to insert a LMA was 0.09 mg/kg with 8 vol% sevoflurane. With isotonic regression, cED95 of rocuronium was 0.13 mg/kg (95% confidence intervals 0.096−0.14 mg/kg). Conclusions: This study demonstrated that the cED50 and cED95 of rocuronium were 0.09 mg/kg and 0.13 mg/kg in children respectively. It provides satisfactory conditions for LMA insertion in anesthetized children and decreases the excessive hemodynamic change.