脑电双频指数用于深低温停循环期间脑氧代谢评估的可行性

A study of bispectral index predicting the cerebral oxygen metabolism during deep hypothermia with circularory arrest

目的探讨深低温停循环(DHCA)期间脑电双频指数(BIS)用于评估脑氧代谢状况的可行性。方法DHCA下大血管手术19例,均采用芬太尼—异丙酚静脉复合全麻。DHCA时间为43±8min,选取右锁骨下动脉插管、阻断升主动脉、鼻咽温降至28℃、降至18℃分钟时、降至18℃30分钟时、恢复全流量10分钟时七个时点测定下述指标:BIS、SjvO2、PaCO2、Glu、Hct。结果随CPB开始、心脏停跳及降温过程BIS值呈明显的下降趋势,鼻咽温降至18℃时达最低值,SjvO2、PaCO2、Glu则表现出上升趋势,BIS、SjvO2、Glu三指标与T1时比较差异有显著意义(P<0.05),其中BIS与SjvO2、Glu呈负相关。整个DHCA阶段BIS值无明显改变,与SjvO2失去相关性。结论无法找出DHCA期间BIS与脑氧代谢的对应关系,可能与实际脑灌注流量变异较大有关,BIS难以作为监测脑氧代谢的指标。

Objective To investigate the correlation of hispectral index（BIS） and quantity electroencephalogram（qEEG）, with the concurrent cerebral oxygen metabolic changes during Deep hypothermia with circulatory arrest （DHCA）. Methods nineteen patients underwent surgical repair of extensive aortic dissection and aneurysm during DHCA, The BIS.SjvO2.PaCO2.Glu.Hct were recorded at seven special status. Results With decreasing tempture the BIS decreased and to the lowest at 18℃, SjvO2.PaCO2.Glu increasing. BIS is not correlated linearly with the Magnitude of the cerehral oxygen metabolism. Conclusion during DHCA cerebral oxygen metabolic changes can not be reflected by BIS.