脑电双频指数在监测重度颅脑损伤合并顽固性颅内高压患者的巴比妥盐昏迷中的应用

背景在重症创伤性颅脑损伤（TBI）患者运用巴比妥盐治疗中，通常将暴发．抑制模式的脑电图（EEG）作为监测指标。双频指数（BIS）是脑电图的衍生物，并且考虑到了皮层电静止。本研究测定一定范围内的BIS是否可以预测一个特殊的暴发．抑制模式。方法前瞻性收入11例应用巴比妥盐治疗的TBI患者。每天记录1小时EEG，每5分钟从原始EEG上计算1分钟的暴发数量及抑制率[抑制率（SREBG）：从EEG上得到的前60秒皮层电静止所占的百分率]，并与BIS-XPTM监测仪上伴行的数据对比[BIS和抑制商（SRBIS）]。巴比妥盐昏迷的最佳水平定义为脑电图上每分钟有2—5个暴发发生。根据所得数据求出最佳水平的BIS预测值范围，对每一例数据都测定其精确度。结果SREEG和SRBIS一致性很高[组间相关系数0．94（95％可信区间：0．90—0.96）]。SREEG和BIS之间有显著相关性。在某些受试者中观察到显著不一致性。BIS值在6～15范围之间时预测精确度最高。结论应用巴比妥盐治疗的重症创伤性颅脑损伤患者，BIS和SREEG有很高相关性。当BIS值〈6时巴比妥盐输注速率需要降低，而当BIS值〉15时，则需要升高。BIS和抑制图形的关系应该周期性地通过EEG模拟信号（BIS-XPTM所示）来校正。

BACKGROUND： Barbiturate therapy in severely traumatic brain-injured （TBI） patients is usually monitored by an electroencephalogram （EEG） with burst-suppression pattern as a target. The Bispectral Index （BIS） is derived from EEG and considers cortical silence. We sought to determine whether a BIS range could predict a specific burst-suppression pattern. METHODS： Eleven TBI patients treated with barbiturate were included prospectively. EEG was recorded daily for 1 h. Every 5 vain, the number of bursts and the suppression ratio （ suppression ratio from EEG [ SREEG ] ： percentage of last 60 s in cortical silence） was calculated for 1 min on the raw EEG and compared to concomitant data from the BIS-XPTM （BIS and suppression ratio [ SRBIS] ）. The optimal level of barbiturate coma was defined as 2 -5 bursts/rain in the EEG. A BIS range predictive of optimal level was determined from all data and its accuracy was studied for each examination. RESULTS： Agreement between SlOEG and SRBIS was high （interclass correlation coefficient 0. 94 [ 95% confidence interval： 0. 90 -0. 961 ）. There was a significant association between SREEG and BIS. Significant disagreements were observed in some examinations. The best accuracy to predict optimal pattern was obtained with a BIS range from 6 to 15. CONCLUSION： The relationship between BIS and SREEG was high in TBI patients treated with barbiturates. The rate of barbiturate infusion might be decreased if BIS is 〈6 or increased if BIS is 〉15. Correspondence between BIS and suppression pattern should periodically be checked by observation of the EEG analogical signal （as displayed by BIS-XPTM）.