Schwilden H, Stoeckel H
Br J Anaesth. 1987 Jun;59(6):738-45. doi: 10.1093/bja/59.6.738.
In 14 patients undergoing elective surgery the EEG was studied during anaesthesia with isoflurane and nitrous oxide (in oxygen) at 1.3 and 1.5 MAC. The distribution of spectral EEG indices of the baseline EEG, during the intraoperative and recovery periods were established and compared. Median frequency exhibited the most clear separation between the distributions during recovery and the intraoperative period. During anaesthesia, the median values were found to be lower than 5 Hz; when the patient was conscious, the EEG median frequency values were greater than 6 Hz. Time to recovery was 13.4 +/- 2.9 min and 30.0 +/- 8.5 min for the groups treated with 1.3 and 1.5 MAC, respectively. Burst suppression was observed during the loading period in all patients treated with 1.5 MAC and in five patients out of seven receiving 1.3 MAC. The average duration of the period of burst suppression was markedly greater in the group receiving 1.5 MAC than in the group receiving 1.3 MAC. It is concluded that devices designed for EEG trend monitoring during anaesthesia should preferably depict a frequency measure, and allow for burst suppression recognition before spectral analysis.
在14例接受择期手术的患者中，研究了在1.3和1.5倍最低肺泡有效浓度（MAC）下使用异氟烷和氧化亚氮（与氧气混合）麻醉期间的脑电图（EEG）。确定并比较了基线脑电图、术中及恢复期的频谱脑电图指数分布。中位频率在恢复期和术中分布之间表现出最明显的差异。麻醉期间，中位数值低于5Hz；患者清醒时，脑电图中位频率值大于6Hz。1.3和1.5MAC治疗组的恢复时间分别为13.4±2.9分钟和30.0±8.5分钟。在所有接受1.5MAC治疗的患者以及接受1.3MAC治疗的7例患者中的5例患者的负荷期观察到爆发抑制。接受1.5MAC治疗的组中爆发抑制期的平均持续时间明显长于接受1.3MAC治疗的组。得出结论，设计用于麻醉期间脑电图趋势监测的设备最好描绘频率测量，并在频谱分析之前能够识别爆发抑制。
