Smith N T, Westover C J, Quinn M, Benthuysen J L, Silver H D, Sanford T J
J Clin Monit. 1986 Jan;2(1):15-21. doi: 10.1007/BF01619173.
Using aperiodic analysis, we examined the impact on the electroencephalogram (EEG) of muscle activity from opiate-induced rigidity with alfentanil. We compared two groups of patients, one receiving alfentanil with neuromuscular blocking agents and the other group receiving no relaxants. The alfentanil-induced muscle rigidity exerted a noticeable effect on the EEG, with a moderate effect on total power at 1 Hz; a marked effect on the total number of waves, cumulative percent power at 3 Hz, and average power at 17 to 19 Hz; and a striking effect on F90, the frequency below which 90% of the power resides. The presence of electromyographic (EMG) noise in the EEG consistently altered the variables derived from the EEG, so that anesthetic depth appeared less than it actually was. This was true in spite of the fact that we gave slightly more alfentanil in the group not receiving a relaxant. Although the observed muscle activity was greater than that usually seen clinically, and may have differed qualitatively, the results do serve as a warning that muscle noise can interfere with the EEG. Currently, there is no computerized technique that will reject or account for this noise, and we must depend on observation to recognize the EMG patterns within the EEG, either with the raw recording or with a detailed analysis (such as aperiodic analysis), and to compensate for this noise if possible. Techniques that average the EEG or that present a single number have difficulty providing this information. These results do not detract from the usefulness of the EMG contained in EEG recordings as a supplementary or complementary indicator of anesthetic lightness.
我们采用非周期性分析方法，研究了阿芬太尼所致阿片类药物诱导的强直状态下肌肉活动对脑电图（EEG）的影响。我们比较了两组患者，一组接受阿芬太尼加神经肌肉阻滞剂，另一组未接受松弛剂。阿芬太尼诱导的肌肉强直对EEG产生了显著影响，对1Hz时的总功率有中度影响；对波的总数、3Hz时的累积功率百分比以及17至19Hz时的平均功率有显著影响；对F90（功率90%所处频率以下的频率）有显著影响。EEG中肌电图（EMG）噪声的存在持续改变了从EEG得出的变量，使得麻醉深度看似比实际情况浅。尽管在未接受松弛剂的组中我们给予了稍多的阿芬太尼，但情况依然如此。虽然观察到的肌肉活动大于临床上通常所见，且可能在性质上有所不同，但这些结果确实警示了肌肉噪声会干扰EEG。目前，尚无计算机技术能够排除或处理这种噪声，我们必须依靠观察来识别EEG中的EMG模式，无论是原始记录还是详细分析（如非周期性分析），并尽可能补偿这种噪声。对EEG进行平均或给出单个数值的技术难以提供此类信息。这些结果并不影响将EEG记录中包含的EMG作为麻醉浅度的补充或辅助指标的有用性。
