Median effective dose of oxycodone inhibiting responses to laryngeal mask airway insertion when combined with propofol in adult female patients / 中华麻醉学杂志

ABSTRACT

Objective To determine the median effective dose (ED50) of oxycodone inhibiting responses to laryngeal mask airway (LMA) insertion when combined with propofol in the adult female patients.Methods Female patients,aged 18-60 yr,with body mass index of 18-24 kg/m2,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,scheduled for elective gynecologic surgery,were included.ED50 of oxycodone was determined by up-and-down sequential technique.Anesthesia was induced by target-controlled infusion of propofol at target plasma concentration of 3.0 μg/ml.Oxycodone was injected at the initial dose of 0.11 mg/kg after the target effect-site and plasma concentrations were balanced.LMA was inserted at 5 min following injection.When the response to LMA insertion was positive,the concentration of oxycodone was increased/decreased in the next patient.The difference between the two successive doses was 0.02 mg/kg.LMA insertion response was defined as occurrence of swallowing,biting on the LMA and bucking and/or body movement during insertion.Probit analysis was used to calculate the ED50 and 95％ confidence interval of oxycodone inhibiting responses to LMA insertion when combined with propofol.Results The ED50 (95％ confidence interval) of oxycodone inhibiting responses to LMA insertion was 0.095 (0.080-0.108) mg/kg when combined with propofol.Conclusion The ED50 of oxycodone inhibiting responses to LMA insertion is 0.095 mg/kg when combined with propofol in the adult female patients.