He Lin, Zhang Xue-Feng
Department of Anesthesiology, Children's Hospital of Fudan University, Shanghai 201102, China.
Zhonghua Yi Xue Za Zhi. 2009 Apr 21;89(15):1021-3.
To investigate the minimum alveolar concentration (MAC) of sevoflurane required for insertion of laryngeal mask airway (LMA) in anesthetized children.
27 children, aged 3-8, with an ASA physical status I or II, underwent elective surgery under general anesthesia induced by inhalation of 8% sevoflurane in oxygen. After loss of eyelash reflex, the designated end-tidal concentration of sevoflurane remained stable for at least 10 min, and then the LMA was inserted. Each target concentration at the time of insertion was predetermined by the Dixon up-and-down method (with 0.2% as a step size) starting at 2.0% end-tidal concentration of sevoflurane. Successful insertion was defined as excellent inserting condition (fully relaxed jaw, no coughing, and no movement of the limbs, no breath holding, and no laryngospasm).
The mean MAC of sevoflurane to achieve successful LMA insertion in 50% of children was (2.01 +/- 0.19)%, and the ED(95) was 2.36% (95% CI 2.15% - 4.15%).
LMA insertion can be safely accomplished without coughing, moving, or any other airway complications in 50% and 95% of children at 2.01% and 2.36% end-tidal concentrations of sevoflurane.
探讨七氟醚用于麻醉儿童喉罩置入的最低肺泡有效浓度（MAC）。
27例年龄3至8岁、ASA身体状况分级为I或II级的儿童，在吸入8%七氟醚与氧气混合气体诱导全身麻醉下接受择期手术。睫毛反射消失后，七氟醚的呼气末浓度保持稳定至少10分钟，然后置入喉罩。置入时的每个目标浓度由Dixon上下法预先确定（步长为0.2%），起始呼气末七氟醚浓度为2.0%。成功置入定义为置入条件良好（下颌完全松弛、无咳嗽、四肢无活动、无屏气、无喉痉挛）。
50%儿童成功置入喉罩时七氟醚的平均MAC为（2.01±0.19）%，ED(95)为2.36%（95%CI 2.15% - 4.15%）。
呼气末七氟醚浓度为2.01%和2.36%时，50%和95%的儿童可安全完成喉罩置入，且无咳嗽、活动或任何其他气道并发症。
