异氟醚吸入全麻深度与脑电功谱的关系(附12例病例分析)

RELATIONSHIP BETWEEN EEG POWER SPECTRUM AND THE ANESTHETIC DEPTH OF ISOFLURANE

目的：探讨脑电功谱与异氟醚吸入全麻深度之间的关系。方法：采用ＡｓｐｅｃｔＡ１０００脑电功谱仪对１２例行异氟醚麻醉的患者，分别于麻醉诱导前（基础值）、吸入异氟醚１０ｖｏｌ％、２５ｖｏｌ％、４０ｖｏｌ％并保持上述异氟醚呼气末浓度稳定各１５ｍｉｎ后、以及气管拔管前共５个时相，测定α、β、θ、δ波、双频指数（ＢＳＩ）、边缘频率（ＳＥＦ）和中心频率（ＭＰＦ）。结果：浅麻醉时或麻醉恢复期，脑电功谱呈优势快波，ＢＳＩ、ＳＥＦ和ＭＰＦ上升；较深麻醉时，脑电功谱呈优势慢波，ＢＳＩ、ＳＥＦ和ＭＰＦ降低。结论：①脑电功谱，尤其ＢＳＩ是麻醉中反映麻醉深度的较好的可信指标；②麻醉对神经中枢的效应并非单纯抑制，而是呈兴奋抑制的双向效应。

Objective:To observe the relationship between EEG power spectrum and anesthetic depth of isoflurane.Methods:12 patients undergoing isoflurane anesthesia were observed with Aspect A 1 000 computerized EEG monitor.α,β,θ,δ frequency,bispectral index(BSI),95% spectral edge frequency(SEF) and median power frequency(MPF)were measured during the following phases:before anesthesia induction,after inhalation of isoflurane 1 0 vol%,2 5 vol% and 4 0 vol% separately until their permanent end tidal concentrations kept constant for 15 minutes,and before extubation of endotracheal intubation.Results:The EEG power spectrum is dominated with slow frequency during deep anesthesia,BSI,SEF and MPF were also decreased;however,the changes of EEG power spectrum were reversed during light anesthesia and during the recovery of anesthesia,the EEG power spectrum is dominated with fast frequency,BSI,SEF and MPF were increased.Conclusion:①EEG power spectrum,especially BSI,is a sensitive and satisfactory indicator for the evaluation of anesthetic depth of isoflurane;②the effects of anesthesia is a biphasic phase on central nervous system.