Walsh Timothy S, Ramsay Pamela, Lapinlampi T Petteri, Särkelä Mika O K, Viertiö-Oja Hanna E, Meriläinen Pekka T
Edinburgh Royal Infirmary, 51 Little France Crescent, Old Dalkeith Road, EH16 4SA Edinburgh, Scotland.
Intensive Care Med. 2008 Feb;34(2):308-15. doi: 10.1007/s00134-007-0858-x. Epub 2007 Sep 27.
To assess whether the Entropy Module (GE Healthcare, Helsinki, Finland), a device to measure hypnosis in anesthesia, is a valid measure of sedation state in critically ill patients by comparing clinically assessed sedation state with Spectral Entropy
Prospective observational study.
Teaching hospital general ICU.
30 intubated, mechanically ventilated patients without primary neurological diagnoses or drug overdose receiving continuous sedation.
Monitoring of EEG and fEMG activity via forehead electrodes for up to 72h and assessments of conscious level using a modified Ramsay Sedation Scale.
475 trained observer assessments were made and compared with concurrent Entropy numbers. Median State (SE) and Response (RE) Entropy values decreased as Ramsay score increased, but wide variation occurred, especially in Ramsay 4-6 categories. Discrimination between different sedation scores [mean (SEM) P(K) value: RE 0.713 (0.019); SE 0.710 (0.019)] and between lighter (Ramsay 1-3) vs.deeper (Ramsay 4-6) sedation ranges was inadequate [P(K): RE 0.750 (0.025); SE 0.748 (0.025)]. fEMG power decreased with increasing Ramsay score but was often significant even at Ramsay 4-6 states. Frequent "on-off" effects occurred for both RE and SE, which were associated with fEMG activity. Values switched from low to high values even in deeply sedated patients. High Entropy values during deeper sedation were strongly associated with simultaneous high relative fEMG powers.
Entropy of the frontal EEG does not discriminate sedation state adequately for clinical use in ICU patients. Facial EMG is a major confounder in clinical sedation ranges.
通过比较临床评估的镇静状态与频谱熵，评估用于麻醉中催眠测量的熵模块（通用电气医疗集团，芬兰赫尔辛基）是否为危重病患者镇静状态的有效测量指标。
前瞻性观察性研究。
教学医院综合重症监护病房。
30例接受持续镇静、无原发性神经疾病诊断或药物过量的插管机械通气患者。
通过前额电极监测脑电图（EEG）和肌电图（fEMG）活动长达72小时，并使用改良的拉姆齐镇静评分评估意识水平。
进行了475次经过培训的观察者评估，并与同时测得的熵数值进行比较。随着拉姆齐评分增加，中位状态熵（SE）和反应熵（RE）值降低，但存在广泛差异，尤其是在拉姆齐4 - 6分类中。不同镇静评分之间的辨别力[平均值（标准误）P（K）值：RE 0.713（0.019）；SE 0.710（0.019）]以及较浅（拉姆齐1 - 3）与较深（拉姆齐4 - 6）镇静范围之间的辨别力不足[P（K）：RE 0.750（0.025）；SE 0.748（0.025）]。fEMG功率随着拉姆齐评分增加而降低，但即使在拉姆齐4 - 6状态下也常常显著。RE和SE均频繁出现“开 - 关”效应，这与fEMG活动相关。即使在深度镇静患者中，数值也会从低值切换到高值。深度镇静期间的高熵值与同时出现的高相对fEMG功率密切相关。
前额脑电图的熵在ICU患者的临床应用中不能充分区分镇静状态。面部肌电图是临床镇静范围内的主要混杂因素。
