目的

探讨鼻导管吸入七氟烷全麻下行舌系带延长术患儿的半数有效量（ED50）和95%有效量（ED95）。

方法

择期行舌系带延长术的患儿140 例，根据鼻导管七氟烷吸入浓度（2.0%、2.5%、3%、3.5%、4%、4.5%、5%）随机分为A、B、C、D、E、F、G 七组（n=20），患儿术前经8%七氟烷面罩吸入诱导建立静脉通路，然后改为鼻导管吸入，七氟烷挥发罐持续输出预定浓度10 min 后开始行舌系带延长术，观察并记录各组患儿体动情况，围术期心率、血压、以及呼吸情况。 采用Probit 法计算七氟烷ED50 和ED95 及其95% CI。

结果

随着吸入七氟烷浓度增加，患儿体动减少。 七组有效率分别为30%、45%、55%、65%、95%、100%、100%。 七氟烷吸入浓度的ED50 为2.71%（95% CI：2.37%～2.96%），ED95 为4.32%（95% CI：3.93%～5.03%）。

结论

全麻下行舌系带延长术时，经鼻导管吸入七氟烷浓度ED50 值为2.71%，ED95 为4.32%，为临床上安全有效使用七氟烷吸入全麻下行小儿口腔门诊手术提供了依据。

Objective

To investigate the median effective dose （ED50） and the 95 percentile effective dose （ED95） of sevoflurane through nasal cannula for pediatric frenulotomy of ankyloglossia.

Methods

One hundred and forty pediatri cases， scheduled for selective frenulotomy for ankyloglossia，were randomly divided into A， B， C， D， E， Fand G groups according to the sevoflurane concentrations（2.0%、2.5%、3%、3.5%、4%、4.5%、5%） through nasal cannulas （n=20 for each group）. Anesthesia was induced with 8% sevoflurane delivered in 100% oxygen via face mask for peripheral intravenous access， then maintained with different concentration of sevoflurane through nasal cannula. Frenulotomy for ankyloglossia started after the inspired concentration of sevoflurane was adjusted to maintenance concentration for 10 min. periopertative heart rates， blood pressure， desaturation to SpO₂ ＜95% and the occurrence of movements were recorded. The ED50 and ED95 of sevoflurane and 95% confidence interval （CI） were determined by probit method.

Results

Movements in response to incision reduced at the higher sevoflurane concentration. The rates of successful skin incision were 30% for group A， 45%for group B， 55% for group C， 65% for group D， 95% for group E， 100% for group F， 100% for group G. The ED50 and ED95（95% CI） of sevoflurane concentration were 2.71%（2.37%～2.96%） and 4.32%（3.93% ～5.03%） respectively.

Conclusion

The ED50 and ED95 of inspired concentration of sevoflurane through nasal cannula were 2.71% and 4.32%.