复合七氟醚吸入用于小儿无肌松气管插管时瑞芬太尼的半数有效血浆靶浓度

Half-effective target plasma concentration of remifentanil needed for tracheal intubation without neuromuscular relaxant in children when combined with sevoflurane inhalation

目的探讨复合七氟醚吸入用于小儿无肌松气管插管时瑞芬太尼的半数有效血浆靶浓度（cpSO）。方法择期全麻手术患儿26例，年龄3—6岁，ASAⅠ-Ⅱ级。初始七氟醚吸入浓度为8％，氧流量3L／min，患儿意识消失后调整七氟醚吸入浓度，维持七氟醚呼气末浓度为2．7％。3rain后采用Minto药代动力学参数模型靶控输注瑞芬太尼，待效应室靶浓度与血浆靶浓度相同时行气管插管。采用序贯法进行试验，瑞芬太尼血浆靶浓度由4．0ng／ml开始，相邻浓度梯度为0．5ng／ml。应用Probit检验计算瑞芬太尼的CpSO及95％可信区间。结果复合2．7％七氟醚吸入用于小儿无肌松气管插管时瑞芬太尼的cpSO为4．10ng／ml，其95％CI为3．60～4．59ng／ml。结论复合2．7％七氟醚吸入用于小儿无肌松气管插管时瑞芬太尼的Cp50为4．10ng／ml。

Objective To determine the half-effective target plasma concentration （Cp50） of remifentanil needed for tracheal intubation without neuromuscular relaxant in children when combined with sevoflurane inhalation. Methods Twenty six children aged 3 -6 years old with ASA I -II who were undergone elective surgery under general anesthesia were enrolled in the study. The initial sevoflurane inhalation concentration was set at 8% and the fresh flow of oxygen was set at 3 L/rain. As soon as consciousness disappeared, the sevoflurane concentration was adjusted to 2. 7% as end-tidal concentration. Three min later, remifentanil was administered by target-controlled infusion with a Minto model. Tracheal intubation was performed after the equilibration between plasma and effectsite concentration. Target plasma concentration of remifentanil was determined by up-and-down sequential trial. The initial target plasma remifentanil concentration was set at 4. 0 ng/ml and the gradient of two target plasma concentrations was 0. 5 ng/ml. The Cp50 of remifentanil and 95% confidence interval（95% CI）were determined by the Probit Analysis. Results The Cp50 of remifentanil needed for tracheal intubation without neuromuscular relaxant was 4. 10 ng/ml in children whencombined with 2.7% sevoflurane inhalation, and 95% CI was 3. 60 -4. 59 ng/ml. Conclusion The Cp50 of remifentanil needed for tracheal intubation without neuromuscular relaxant was 4. 10 ng/ml in children when combined with 2.7% sevoflurane inhalation.