芬太尼复合七氟醚诱导无肌松插管的量效关系

目的 观察芬太尼复合七氟醚诱导无肌松插管的半数有效量(ED_(50)).方法 择期短小手术患者26例,ASA Ⅰ-Ⅱ,年龄25～45岁纳入研究.8%七氟醚肺活量诱导,跟睑反射消失后,维持呼气末七氟醚浓度3%,按照改良Dixon序贯法调整芬太尼剂量(剂量梯度为0.4 μg/kg),静脉注射芬太尼4 min后气管插管.记录麻醉诱导前平均动脉压(MAP)、心率(HR)和熵指数(Entropy indices)的基础值以及捅管前后1 min及插管后3 min的变化.结果 8%七氟醚诱导,维持呼气末浓度3%,成功无肌松气管插管的芬太尼ED_(50)为(1.2±0.3)μg/kg,采用probit分析方法 芬太尼ED_(50)和ED95及(95%可信区间)分别为1.2 μg/kg(0.9～1.6) μg/kg和1.9 μg/kg(1.6～3.9) μg/kg.结论 8%七氟醚肺活量诱导,维持呼气末七氟醚浓度3%,无肌松满意气管插管的芬太尼ED_(50)为(1.2±0.3)μg/kg.

The dose-response relationship of fentanil for tracheal intubation during sevoflurane induction without neuromuscular blockade

Objective To determine the bolus dose of fentanil required to provide successful intu-bating conditions following inhalation induction of anesthesia using sevoflurane without neuromuscular blockade in adult anesthesia. Methods Twenty-six ASA Ⅰ or Ⅱ patients aged 25-45 years undergoing general anesthesia for short surgery were enrolled into this study. Anesthesia was induced with seveflurane 8% in oxygen,after the loss of eyelash reflex, end-tidal sevoflurane concentration 3% was maintained, and predetermined dose of fentanil was injected over 30s. The dose of fentanil was determined by modified Dix-on's up-and-down method (0.4 μg/kg as a step size). Four minutes after the end of bolus administration of fentanil ,the trachea was intubated. Mean blood pressure,heart rate and Entropy indices were recorded at anesthetic induction, before, 1 min and 3 min after intubation. Results The bolus dose of fentanil for suc-cessful tracheal intubation was (1.2±0.3 ) μg/kg in 50% of patients during inhalation induction. From probit anlysis,50% effective dose (ED_(50)) and ED95 values (95% confidence limits) of fentanil were 1.2 μg/kg (0.9-1.6) μg/kg and 1.9 μg/kg (1.6-3.9) μg/kg,respectively. Conclusion Using the modi-fied Dixon's up-and-down method, the bolus dose of fentanil for successful tracheal intubation was (1.2±0.3) μg/kg in 50% of adult patients during 8% sevoflurane induction and maintained with end-tidal con-centration 3% without neuromuscular blocking agent in anesthesia.