Martorano P, Facco E, Falzetti G, Pelaia P
Neurosciences Department, Anesthesia and Intensive Care Section, Polytechnic University of Marche, Ancona, Italy.
Clin Neurophysiol. 2007 Mar;118(3):505-12. doi: 10.1016/j.clinph.2006.11.002. Epub 2006 Dec 20.
The assessment of the level of anesthesia is a very hard task, since no gold standard has stood out in the past three decades. Middle Latency Auditory Evoked Potential (MLAEP) is one of the most popular neurophysiological tools for anesthesia monitoring. Recently, Spectral Entropy (SpEn) has been introduced: it provides two different parameters, State Entropy (SE) and Response Entropy (RE). The aim of this prospective study is to check SpEn end-point, comparing it to MLAEPs in neurosurgical anesthesia.
Twenty patients submitted to elective supratentorial neurosurgery for removal of a temporal-parietal meningioma were included in the study. SpEn and MLAEPs were simultaneously monitored using the M-entropy module S/5 (GE Health Care, Helsinki, Finland) and Alaris Medical System AEP-ARX index monitor (AAI) (Kidemosevej, Denmark), respectively.
Four thousand and sixty four data points of SE, RE and AAI were recorded and ROC curves comparing AAI to RE and SE showed a highly significant (p<0.0001) area under the curve. The RE and SE cut-off values (showing maximal sensitivity with maximal specificity) to discriminate anesthesia from awake or consciousness sedation were 61 and 58, respectively. However, in a group of data points, low AAI was associated to high SpEn (577 data points for RE and 770 for SE) and vice versa (31 data points for RE and 43 for SE). The prediction probability for SE was 0.977 and for RE was 0.968.
Our results suggest that SpEn is as effective as AAI.
Our results show that SpEn is able to discriminate between the levels of wakefulness and surgical anesthesia. However, the meaning of data showing a discrepancy between AAI and SpEn is not yet clear and calls for further study.
麻醉深度评估是一项非常艰巨的任务，因为在过去三十年中尚未出现金标准。中潜伏期听觉诱发电位（MLAEP）是麻醉监测中最常用的神经生理学工具之一。最近，引入了频谱熵（SpEn）：它提供两个不同的参数，状态熵（SE）和反应熵（RE）。本前瞻性研究的目的是在神经外科麻醉中检查SpEn终点，并将其与MLAEP进行比较。
本研究纳入了20例因颞顶叶脑膜瘤行择期幕上神经外科手术的患者。分别使用M-熵模块S/5（通用电气医疗集团，芬兰赫尔辛基）和Alaris医疗系统AEP-ARX指数监测仪（AAI）（丹麦基德莫瑟韦）同时监测SpEn和MLAEP。
记录了4064个SE、RE和AAI数据点，比较AAI与RE和SE的ROC曲线显示曲线下面积具有高度显著性（p<0.0001）。区分麻醉与清醒或意识镇静的RE和SE临界值（显示最大敏感性和最大特异性）分别为61和58。然而，在一组数据点中，低AAI与高SpEn相关（RE为577个数据点，SE为770个数据点），反之亦然（RE为31个数据点，SE为43个数据点）。SE的预测概率为0.977，RE的预测概率为0.968。
我们的结果表明SpEn与AAI一样有效。
我们的结果表明SpEn能够区分清醒和手术麻醉水平。然而，显示AAI和SpEn之间存在差异的数据的意义尚不清楚，需要进一步研究。
