Schmidt Gunter N, Bischoff Petra, Standl Thomas, Hellstern Angelika, Teuber Olaf, Schulte Esch Jochen
Department of Anesthesiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany.
Anesthesiology. 2004 Dec;101(6):1283-90. doi: 10.1097/00000542-200412000-00007.
Different analytical concepts were introduced to quantify the changes of the electroencephalogram. The Datex-Ohmeda S/5 Entropy Module (Datex-Ohmeda Division, Instrumentarium Corp., Helsinki, Finland) was the first commercial monitor based on the entropy generating two indices, the state entropy (SE) and the response entropy (RE). The aim of the current study was to compare the accuracy of SE and RE with the Bispectral Index(R) monitor (BIS(R); Aspect Medical Systems, Newton, MA) during propofol-remifentanil anesthesia.
The authors investigated 20 female patients during minor gynecologic surgery. SE, RE, BIS, mean arterial blood pressure, heart rate, and sedation level were recorded every 20 s during stepwise increase (target-controlled infusion, 0.5 microg/ml) of propofol until the patients lost response. Five minutes after loss of response, remifentanil infusion (0.4 microg . kg(-1) . min(-1)) was started. Spearman correlation coefficient and prediction probability were calculated for sedation levels with SE, RE, BIS, mean arterial blood pressure, and heart rate. The ability of the investigated parameters to distinguish between the anesthesia steps awake versus loss of response, awake versus anesthesia, anesthesia versus first reaction, and anesthesia versus extubation was analyzed with the prediction probability.
SE correlates best with sedation levels, but no significant differences of the prediction probability values among SE, RE, and BIS were found. The prediction probability for all investigated steps of anesthesia did not show significant differences among SE, RE, and BIS. SE, RE, and BIS were superior to mean arterial blood pressure and heart rate.
SE, RE, and BIS revealed similar information about the level of sedation and allowed the authors to distinguish between different steps of anesthesia. Both monitors provided useful additional information for the anesthesiologist.
引入了不同的分析概念来量化脑电图的变化。Datex-Ohmeda S/5熵模块（Datex-Ohmeda部门，Instrumentarium公司，芬兰赫尔辛基）是首个基于熵生成两个指标的商业监测仪，即状态熵（SE）和反应熵（RE）。本研究的目的是比较在丙泊酚-瑞芬太尼麻醉期间，SE和RE与脑电双频指数（BIS；Aspect Medical Systems公司，美国马萨诸塞州牛顿）监测仪的准确性。
作者对20例接受小型妇科手术的女性患者进行了研究。在丙泊酚逐步增加（靶控输注，0.5微克/毫升）直至患者失去反应的过程中，每20秒记录一次SE、RE、BIS、平均动脉血压、心率和镇静水平。在失去反应5分钟后，开始输注瑞芬太尼（0.4微克·千克⁻¹·分钟⁻¹）。计算SE、RE、BIS、平均动脉血压和心率与镇静水平的Spearman相关系数和预测概率。使用预测概率分析所研究参数区分清醒与失去反应、清醒与麻醉、麻醉与首次反应以及麻醉与拔管等麻醉阶段的能力。
SE与镇静水平的相关性最佳，但在SE、RE和BIS之间未发现预测概率值的显著差异。在所有研究的麻醉阶段，SE、RE和BIS的预测概率均未显示出显著差异。SE、RE和BIS优于平均动脉血压和心率。
SE、RE和BIS显示出关于镇静水平的相似信息，并使作者能够区分不同的麻醉阶段。这两种监测仪都为麻醉医生提供了有用的额外信息。
