Dutton R C, Smith W D, Smith N T
Department of Anesthesia, Kaiser Permanente Medical Center, Hayward, CA 94545, USA.
J Clin Monit. 1996 Mar;12(2):127-39. doi: 10.1007/BF02078133.
Our objective was to evaluate the performance of the EEG as an indicator of anesthetic depth by measuring EEG prediction of movement response to surgical stimuli.
While using 5 different combinations of isoflurane, 70% N2O, and fentanyl, we measured the EEG of 246 patients during pelvic laparoscopy and observed their movement responses to opening stimuli (defined as skin incision, CO2 needle insertion, or trocar insertion) and also to closing stimuli (defined as sutures during incision closure). The EEG was expressed as F95, the frequency in hertz below which resides 95% of the power in the EEG frequency spectrum. The relations between F95 and movement response were expressed as logistic regression curves. F95-response logistic regression curves, which are analogous to dose-response curves, were calculated for each of the 2 stimuli administered during each of the 5 anesthetic techniques. The prediction of patient responsiveness by F95 was tested using beta (beta), a measure of the slope of an F95-response logistic curve. The presence of shifts among the F95-response logistic curves was tested using the differences in F95 values between curves. Hypothesis tests used a level of significance of P = 0.05.
The slopes of the F95-response logistic regression curves showed a statistically significant ability to predict movement response to stimuli for 9 of the 10 combinations of stimuli and anesthetic techniques. We did not calculate an F95-response logistic curve for the tenth combination because it contained burst suppression, which our EEG analysis method was not designed to process. The F95-response logistic curves were shifted relative to each other, and the shifts were affected by the type of stimulus and the combination of anesthetic agents. Referenced to opening curves, the mean shift of the closing curves was +4.2 +/- 0.3 Hz (mean +/- SD). With increasing doses of fentanyl, the use of 70% N2O, or both, the curves shifted to higher values of F95; the range in shifts was 0.2 to 8.1 Hz. The slope beta values of the F95-response logistic curves and the shifts among the curves were similar to the beta values and shifts that might be expected from changes in anesthetic agent doses.
The EEG, expressed as F95, predicted movement response to surgical stimuli during combinations of isoflurane, 70% N2O, and fentanyl. The F95-response curves shifted upward on the frequency scale for the less intense stimuli and for anesthetic techniques using 70% N2O, fentanyl, or both. F95 prediction of movement response appeared to be related to anesthetic agent doses. Our F95-response curves may provide helpful guidelines for using F95 to titrate the administration of anesthetic agents and for assessing the depth of general anesthesia.
我们的目的是通过测量脑电图（EEG）对手术刺激的运动反应预测，来评估EEG作为麻醉深度指标的性能。
在使用异氟烷、70%氧化亚氮和芬太尼的5种不同组合时，我们在盆腔腹腔镜检查期间测量了246例患者的EEG，并观察了他们对切开刺激（定义为皮肤切口、二氧化碳针插入或套管针插入）以及缝合刺激（定义为切口缝合期间的缝合）的运动反应。EEG表示为F95，即脑电图频谱中95%功率所在频率以下的赫兹频率。F95与运动反应之间的关系表示为逻辑回归曲线。针对5种麻醉技术中的每一种在每次给予的2种刺激中的每一种，计算类似于剂量反应曲线的F95-反应逻辑回归曲线。使用β（β）测试F95对患者反应性的预测，β是F95-反应逻辑曲线斜率的一种度量。使用曲线之间F95值的差异测试F95-反应逻辑曲线之间的偏移是否存在。假设检验使用的显著性水平为P = 0.05。
F95-反应逻辑回归曲线的斜率显示，对于10种刺激和麻醉技术组合中的9种，具有统计学显著的预测对刺激的运动反应的能力。我们没有为第十种组合计算F95-反应逻辑曲线，因为它包含爆发抑制，而我们的EEG分析方法并非设计用于处理这种情况。F95-反应逻辑曲线相互偏移，并且偏移受到刺激类型和麻醉剂组合的影响。以切开曲线为参考，缝合曲线的平均偏移为+4.2 +/- 0.3赫兹（平均值 +/- 标准差）。随着芬太尼剂量增加、使用70%氧化亚氮或两者同时使用，曲线向更高的F95值偏移；偏移范围为0.2至8.1赫兹。F95-反应逻辑曲线的斜率β值以及曲线之间的偏移与麻醉剂剂量变化可能预期的β值和偏移相似。
以F95表示的EEG预测了异氟烷、70%氧化亚氮和芬太尼组合期间对手术刺激的运动反应。对于强度较小的刺激以及使用70%氧化亚氮、芬太尼或两者的麻醉技术，F95-反应曲线在频率尺度上向上偏移。F95对运动反应的预测似乎与麻醉剂剂量有关。我们的F95-反应曲线可能为使用F95来滴定麻醉剂给药以及评估全身麻醉深度提供有用的指导。
