EEG ANALYSIS AS A MEANS OF MONITORING DEPTH OF PSYCHOSEDATION

我们检查了根据一氧化二氮浓度或客观确定的镇静状态的每个指标的变化，并在静脉输注安定或咪达唑仑后，证实了根据从EEG功率谱计算的频带的中值EEG频率和分量比的波动反映了镇静的深度。在本研究的临床部分，我们评估了在精神镇静下进行牙科治疗期间上述指标的变化和患者的客观发现，结果显示，吸入20%-30%的一氧化二氮的中值EEG频率为5- 6 Hz，通常提供最佳镇静，而吸入40%的一氧化二氮的中值EEG频率小于5 Hz，诱导睡眠状态。另一方面，静脉注射地西泮或咪达唑仑，中位EEG频率在最初增加后逐渐下降，在镇静作用开始后变得稳定。频带分量比显示增加的a-和慢波组件和减少的快波组件在响应于亚硝酸盐吸入：相反，与苯二氮卓类衍生物的快速组件的初始上升，观察到，随后增加的a-组件在整个镇静状态的持续时间。这表明，苯二氮卓类衍生物的中位EEG频率最初的升高是由于苯二氮卓类药物特有的快波效应。在研究的临床部分，苯二氮卓类衍生物给药后中位EEG频率也升高：然而，镇静状态下的频率稳定，当患者出现疼痛或镇静作用减弱时达到峰值。上述结果提示，脑电图中位频率的变化反映了精神镇静的深度和疼痛等应激状态。结果表明，脑电频率中位数是一个有用的指标的深度的精神镇静。

We examined changes in each of the indices according to nitrous oxide concentration or objectively determined sedation state, and after intravenous infusion of diazepam or midazolam, confirmed that the fluctuation of median EEG frequency and component ratios according to a frequency band computed from the EEG power spectrum reflected the depth of sedation. In the clinical component of the study, we assessed such changes in the above indices during dental treatment performed under the psychosedation and the patient's objective findings.The results showed a median EEG frequency of 5-6Hz for inhalation of 20%-30% nitrous oxide, which generally provides optimum sedation, versus one of less than 5 Hz for inhalation of 40% nitrous oxide, which induces a sleep state. With intraveno us diazepam or midazolam, on the other hand, median EEG frequency gradually declined after an initial increase, becoming stable after the onset of sedation. The frequency band component ratios showed an increase in the a-and slow-wave components and a decrease in the fast-wave component in response to nitrous inhalation : in contrast, with the benzodiazepine derivatives an initial rise in the fast component was observed, followed by an increase in the a-component throughout the duration of the sedated state. This suggests that the initial rise in median EEG frequency with benzodiazepine derivatives is due to a fast-ware unique to benzodiazepines.In the clinical component of the study, median EEG frequency also rose after administration of the benzodiazepine derivatives : however, frequency in the sedated state was stable, peaking whenever the patients experienced pain or the sedative effect weakened. The above findings imply that changes in median EEG frequency reflect depth of mental sedation and stress states due to pain, et c. It is concluded that median EEG frequency appears to be a useful index of the depth of psychsedation.