Median effective dose of alfentanil combined with propofol inhibiting responses to laryngeal mask airway insertion in children / 中华麻醉学杂志

ABSTRACT

Objective:To determine the median effective dose(ED 50) of alfentanil combined with propofol inhibiting responses to the laryngeal mask airway(LMA) insertion in children. Methods:American Society of Anesthesiologists Physical Status classification Ⅰ children, aged 6-10 yr, with body mass index of 18-24 kg/m 2, undergoing facial skin pigmented nevus resection, were selected. Propofol(target plasma concentration 3 μg/ml) was given by the target-controlled infusion, alfentanil was intravenously injected, 2 min later LMA was inserted, and anesthesia was maintained with 2%-3% sevoflurane until the end of surgery. The dose of alfentanil was determined by the up-and-down sequential method, the initial dose of alfentanil was 15 μg/kg, when the response to LMA insertion was positive/negative, the dose of alfentanil increased/decreased by 1 μg/kg in the next case. The LMA insertion response was defined as swallowing, bucking, body movement occurred during insertion of the LMA, and this process was repeated until 7th turning points appeared. The ED 50 and 95% confidence interval of alfentanil combined with propofol inhibiting responses to LMA insertion in children were calculated using probit method. Results:The ED 50 of alfentanil combined with propofol inhibiting responses to LMA insertion was 13.18(95% confidence interval 12.43-13.79) μg/kg in children. Conclusions:The ED 50 of alfentanil combined with propofol inhibiting responses to LMA insertion is 13.18 μg/kg in children.