目的:本文通过17例健康个体的单纯氙气麻醉,评价BIS、熵在检测全麻深度中的应用。方法:应用氙气常规诱导并插管后,全麻维持只应用氙气。在诱导、麻醉稳定状态及苏醒时,分别检测BIS、状态熵及反应熵、定量脑电图。 BIS、状态熵及反应熵根据预测概率、敏感性及特异性分析进行评价。记录原始脑电图信号的功率谱。结果:在麻醉中,氙气平均(SD)浓度为66.4% (2.4%),BIS、状态熵及反应熵对意识消失的可能性上预测度较低 (0.455, 0.656, 0.619) ,但随后1分钟,预测度升高 (0.804, 0.941, and 0.929)。此后,上述评价指标均能较好评价麻醉深度。在苏醒时,区分稳态麻醉和意识恢复的预测概率分别为,BIS 0.988、状态熵 0.892、反应熵 0.992。各监测仪之间未发现统计学差异。定量脑电图分析表明,总功率呈整体增加(P < 0.001),额脑θ活动增加 (P < 0.001),α活动增加 (P = 0.003)。结论:BIS和熵作为从脑电图衍生出来的测量镇静深度的指标,在监测氙气麻醉中,在患者意识消失时呈现延迟。在麻醉稳定状态时,BIS及熵均能有效区分意识有无状态。 氙气与异丙酚引起的脑电图的改变基本类似。
2 Anesthesiology. 2008 Jan;108(1):63-70.
• Bispectral index, entropy, and quantitative electroencephalogram during single-agent xenon anesthesia.
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• Laitio RM, Kaskinoro K, Särkelä MO, Kaisti KK, Salmi E, Maksimow A, Långsjö JW, Aantaa R, Kangas K, Jääskeläinen S, Scheinin H.
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• Turku Positron Emission Tomography (PET) Centre, and Department of Anesthesiology and Intensive Care, Turku University Hospital, Turku, Finland. [email protected]
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• BACKGROUND: The aim was to evaluate the performance of anesthesia depth monitors, Bispectral Index (BIS) and Entropy, during single-agent xenon anesthesia in 17 healthy subjects. METHODS: After mask induction with xenon and intubation, anesthesia was continued with xenon only. BIS, State Entropy and Response Entropy, and electroencephalogram were monitored throughout induction, steady-state anesthesia, and emergence. The performance of BIS, State Entropy, and Response Entropy were evaluated with prediction probability, sensitivity, and specificity analyses. The power spectrum of the raw electroencephalogram signal was calculated. RESULTS: The mean (SD) xenon concentration during anesthesia was 66.4% (2.4%). BIS, State Entropy, and Response Entropy demonstrated low prediction probability values at loss of response (0.455, 0.656, and 0.619) but 1 min after that the values were high (0.804, 0.941, and 0.929). Thereafter, equally good performance was demonstrated for all indices. At emergence, the prediction probability values to distinguish between steady-state anesthesia and return of response for BIS, State Entropy, and Response Entropy were 0.988, 0.892, and 0.992. No statistical differences between the performances of the monitors were observed. Quantitative electroencephalogram analyses showed generalized increase in total power (P < 0.001), delta (P < 0.001) and theta activity (P < 0.001), and increased alpha activity (P = 0.003) in the frontal brain regions. CONCLUSIONS: Electroencephalogram-derived depth of sedation indices BIS and Entropy showed a delay to detect loss of response during induction of xenon anesthesia. Both monitors performed well in distinguishing between conscious and unconscious states during steady-state anesthesia. Xenon-induced changes in electroencephalogram closely resemble those induced by propofol.