大脑状态指数和脑电双频谱指数对ICU患者镇静深度的评价

Cerebral state index and bispectral index for monitoring the depth of propofol sedation in ICU patients

目的对靶控输注丙泊酚镇静的ICU患者,评价大脑状态指数（CSI）和脑电双频谱指数（BIS）在监测镇静深度的准确性以及年龄因素对其的影响。方法 Ramsay评分为1的ICU患者,排除中枢神经系统病变、休克以及高脂血症者。按年龄分为两组：A组（年龄20~64岁,16例）和B组（年龄〉64岁,15例）。均以丙泊酚靶控输注镇静,监测并记录各时间点（见正文）平均动脉压、心率、BIS值、CSI值和Ramsay评分,并记录靶控输注系统预测的效应部位浓度值（Ce）。比较Ce、BIS值和CSI值与Ramsay评分值有无相关性,以及Ce与BIS值和CSI值的相关性,并且比较BIS和CSI在老年患者和中青年患者中有无差异。结果随着Ce的增加,Ramsay评分值逐渐升高,CSI值和BIS值逐渐降低,Ramsay评分值、CSI值和BIS值均与Ce有良好的相关性;CSI值和BIS值均与Ramsay评分值有良好的相关性;与中青年患者比较,老年患者CSI值差异具有显著性（P〈0.05）,两组患者BIS值差异无显著性（P〉0.05）。结论靶控输注丙泊酚镇静,CSI和BIS一样能预测ICU患者意识状态的变化;同一个Ramsay评分等级,老年人组CSI值较中青年组低。

[Objective ] To investigate the effectiveness of cerebral state index （CSI） and bispectral index （BIS） in measuring the level of sedation during the target controlled infusion （TCI） of propofol in the elderly in the intensive care unit （ICU）. [Methods] 31 ICU patients whose Ramsay score was 1 were divided into two groups： Group A （20- 64 years old, n =16） and Group B （〉64 years old, n =15）. The electrodes of BIS and CSI were placed according to the instruction manuals before the target controlled infusion of propofol. The level of sedation was assessed using Ramsay score. The target effect-site concentration was set initially at 0.3 μg/mL increasing gradually （seeing the text） until the time when the patients lost consciousness and did not respond to pain stimulation （Ramsay score=6）. CSI and BIS were monitored and recorded. Ramsay score and each effect-site concentration （Ce） were recorded at every time point during the experiment. The mean artery pressure and heart rate were monitored and recorded too. Spearman correlation coefficient was calculated for each sedation level with CSI and BIS. The differences of BIS and CSI between the two groups were calculated. [ Results ] The BIS and CSI values decreased as Ce increased. CSI and BIS correlated well with Ramsay score. Ramsay score correlated well with Ce. There were significant differences be- tween groups of CSI, but no significant differences between groups of BIS. [ Conclusion ] BIS and CSI highly corre- lates with the effect-site concentration. BIS and CSI can distinguish the level of sedation effectively and promptly. But the CSI of the elderly appears to be lower than the youth at the same Ramsay score.