Mowafi Hany A
Department of Anaesthesia, Faculty of Medicine, King Faisal University, Saudi Arabia.
Saudi J Anaesth. 2012 Apr;6(2):131-5. doi: 10.4103/1658-354X.97025.
Objective assessment of sedation depth is a valuable target. Spectral entropy is an anesthetic depth monitor based on the analysis of the electroencephalogram signal.
To evaluate the performance of spectral entropy as an objective measure of sedation state in midazolam-premedicated patients and to correlate it with a clinically assessed sedation score.
This prospective double-blind placebo-controlled study was performed in King Fahd Hospital of the university.
Eighty adult ASA I-II patients were randomly assigned into 4 groups. Patients were premedicated using 0.02, 0.04, or 0.06 mg/kg midazolam or saline intramuscularly. The effect of these doses on the Observer's Assessment of Alertness and Sedation (OAA/S) scale, hemodynamic variables, response entropy (RE), and state entropy (SE), was evaluated at 10, 20, and 30 min after premedication.
Spearman Rank-order correlation analysis to examine the relation between OAA/S and entropy. The ability of spectral entropy to predict the depth of sedation was evaluated using Smith prediction probability.
Midazolam doses ≥0.04 mg/kg produced significant decreases in RE, SE, and OAA/S scores. There was a strong correlation between midazolam dose and OAA/S scale, RE, and SE since Spearman Rank R values were 0.792, 0.822, and 0.745, respectively (P<0.001). In addition, RE and SE were strong predictors of OAA/S level during midazolam sedation with no significant difference in prediction between the 2 entropy components.
Spectral entropy is a reliable measure for the sedative premedication. It may be used to objectively assess the adequacy of midazolam premedication and to determine the dose requirement.
客观评估镇静深度是一个有价值的目标。频谱熵是一种基于脑电图信号分析的麻醉深度监测指标。
评估频谱熵作为咪达唑仑预处理患者镇静状态客观指标的性能，并将其与临床评估的镇静评分相关联。
这项前瞻性双盲安慰剂对照研究在大学的法赫德国王医院进行。
80例成年ASA I-II级患者随机分为4组。患者肌肉注射0.02、0.04或0.06mg/kg咪达唑仑或生理盐水进行预处理。在预处理后10、20和30分钟评估这些剂量对观察者警觉与镇静评分（OAA/S）量表、血流动力学变量、反应熵（RE）和状态熵（SE）的影响。
采用Spearman等级相关分析来检验OAA/S与熵之间的关系。使用史密斯预测概率评估频谱熵预测镇静深度的能力。
咪达唑仑剂量≥0.04mg/kg可使RE、SE和OAA/S评分显著降低。咪达唑仑剂量与OAA/S量表、RE和SE之间存在强相关性，因为Spearman等级R值分别为0.792、0.822和0.745（P<0.001）。此外，RE和SE是咪达唑仑镇静期间OAA/S水平的强预测指标，两种熵成分在预测方面无显著差异。
频谱熵是镇静预处理的可靠指标。它可用于客观评估咪达唑仑预处理的充分性并确定剂量需求。
