Dose-effect relationship of oxycodone inhibiting responses to endotracheal intubation with combination of etomidate-rocuronium during induction of general anesthesia / 中华麻醉学杂志

ABSTRACT

Objective:To determine the dose-effect relationship of oxycodone inhibiting responses to endotracheal intubation with combination of etomidate-rocuronium during induction of general anesthesia.Methods:A total of 120 patients, aged 20-63 yr, with body mass index of 18.0-25.2 kg/m 2, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, scheduled for elective surgery under general anesthesia with tracheal intubation, were divided into 4 groups ( n=30 each) using a random number table method: group O 0.15, group O 0.23, group O 0.34 and group O 0.51.In O 0.15, O 0.23, O 0.34 and O 0.51 groups, oxycodone 0.15 mg/kg, 0.23 mg/kg, 0.34 mg/kg and 0.51 mg/kg were injected intravenously, respectively, 3 min later etomidate 0.3 mg/kg and rocuronium 0.8 mg/kg were intravenously injected in turn, and tracheal intubation was performed using Macintosh laryngoscope.Heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure immediately before intubation and the peak levels of HR, BP and diastolic blood pressure within 3 min after intubation were recorded.The response to endotracheal intubation was defined by the SBP and (or) HR having increased by more than 30% following intubation.The occurrence of adverse events during induction of anesthesia were recorded. Results:The rate of response to endotracheal intubation was 97%, 73%, 27%, and 3% in O 0.15, O 0.23, O 0.34 and O 0.51 groups, respectively.The median effective dose (ED 50) (95% confidence interval) of oxycodone inhibiting responses to endotracheal intubation was 0.259 (0.230-0.292) mg/kg, and the 95% effective dose (ED 95) (95% confidence interval) was 0.387 (0.358-0.420) mg/kg.Only the incidence of hypotension (27%) was significantly higher in group O 0.51 than in the other 3 groups ( P<0.05). Conclusion:With combination with etomidate-rocuronium, the ED 50 and ED 95 of oxycodone inhibiting responses to endotracheal intubation performed using Macintosh laryngoscope during induction of general anesthesia are 0.259 mg/kg and 0.387 mg/kg, respectively, and the optimum dose 0.51 mg/kg is recommended.