Kratzer Stephan, Schneider Michael, Obert David P, Schneider Gerhard, García Paul S, Kreuzer Matthias
Department of Anesthesiology and Intensive Care Medicine, School of Medicine, Technical University Munich, Munich, Germany.
Department of Anesthesiology, Columbia University, New York, NY, United States.
Front Syst Neurosci. 2020 Dec 3;14:599962. doi: 10.3389/fnsys.2020.599962. eCollection 2020.
Electroencephalographic (EEG) Burst Suppression (BSUPP) is a discontinuous pattern characterized by episodes of low voltage disrupted by bursts of cortical synaptic activity. It can occur while delivering high-dose anesthesia. Current research suggests an association between BSUPP and the occurrence of postoperative delirium in the post-anesthesia care unit (PACU) and beyond. We investigated burst micro-architecture to further understand how age influences the neurophysiology of this pharmacologically-induced state. We analyzed a subset of EEG recordings ( = 102) taken from a larger data set previously published. We selected the initial burst that followed a visually identified "silent second," i.e., at least 1 s of iso-electricity of the EEG during propofol induction. We derived the (normalized) power spectral density [(n)PSD], the alpha band power, the maximum amplitude, the maximum slope of the EEG as well as the permutation entropy (PeEn) for the first 1.5 s of the initial burst of each patient. In the old patients >65 years, we observed significantly lower ( < 0.001) EEG power in the 1-15 Hz range. In general, their EEG contained a significantly higher amount of faster oscillations (>15 Hz). Alpha band power ( < 0.001), EEG amplitude ( = 0.001), and maximum EEG slope ( = 0.045) all significantly decreased with age, whereas PeEn increased ( = 0.008). Hence, we can describe an age-related change in features during EEG burst suppression. Sub-group analysis revealed no change in results based on pre-medication. These EEG changes add knowledge to the impact of age on cortical synaptic activity. In addition to a reduction in EEG amplitude, age-associated burst features can complicate the identification of excessive anesthetic administration in patients under general anesthesia. Knowledge of these neurophysiologic changes may not only improve anesthesia care through improved detection of burst suppression but might also provide insight into changes in neuronal network organization in patients at risk for age-related neurocognitive problems.
脑电图爆发抑制（BSUPP）是一种不连续模式，其特征是低电压发作被皮层突触活动的爆发所打断。它可在给予高剂量麻醉时出现。当前研究表明，在麻醉后护理单元（PACU）及其他环境中，爆发抑制与术后谵妄的发生之间存在关联。我们研究了爆发微结构，以进一步了解年龄如何影响这种药物诱导状态的神经生理学。我们分析了先前发表的一个较大数据集中的一部分脑电图记录（n = 102）。我们选择了在视觉上识别出的“沉默秒”之后的初始爆发，即在丙泊酚诱导期间脑电图至少1秒的等电位期之后。我们计算了每位患者初始爆发的前1.5秒的（归一化）功率谱密度[（n）PSD]、α波段功率、最大振幅、脑电图的最大斜率以及排列熵（PeEn）。在65岁以上的老年患者中，我们观察到1 - 15赫兹范围内的脑电图功率显著降低（P < 0.001）。总体而言，他们的脑电图包含显著更多的更快振荡（>15赫兹）。α波段功率（P < 0.001）、脑电图振幅（P = 0.001）和脑电图最大斜率（P = 0.045）均随年龄显著降低，而PeEn增加（P = 0.008）。因此，我们可以描述脑电图爆发抑制期间与年龄相关的特征变化。亚组分析显示，基于术前用药情况，结果没有变化。这些脑电图变化增加了我们对年龄对皮层突触活动影响的认识。除了脑电图振幅降低外，与年龄相关的爆发特征可能会使全身麻醉患者中过度麻醉给药的识别变得复杂。了解这些神经生理变化不仅可以通过改进对爆发抑制的检测来改善麻醉护理，还可能为有年龄相关神经认知问题风险的患者的神经网络组织变化提供见解。
