全麻状态下呼气末二氧化碳对脑电非线性参数的影响

The effect of changes of end-tidal carbon dioxide pressure on the EEG no-linear parameters during general anesthesia

目的探讨全麻状态下不同呼气末二氧化碳对脑电非线性参数的影响及其临床价值。方法选择15例择期行腹部或下肢手术的患者,ASAⅠ～Ⅱ级,麻醉方法采用全凭静脉异丙酚靶控镇静(3μg/ml)。术中将患者呼气末二氧化碳分压调至A组(25±2)mmHg,B组(35±2)mmHg,C组(45±2)mmHg,每组维持15min。监测患者不同呼气末二氧化碳分压时的脑电非线性参数——近似熵(ApEn)、关联维数(D2)和复杂度(Cx),常规监测BP、HR、SpO2、PetCO2。结果每两组之间在呼气末二氧化碳分压有显著性差异的情况下,额部ApEn和Cx的变化均存在显著的差异(P<0.01),D2无显著性差异(P<0.05)。结论术中PetCO2的变化直接影响原始脑电活动,这种变化对麻醉的影响通过非线性脑电监测仪得到认证。

Objective To study the effect of changes of carbon dioxide pressure at the end of expiration on the no-linear parameters during general anesthesia.Methods Fifteen patients undergoing expected abdomen and limb opera-tions were chosen randomly.The combined intravenous anesthesia with propofol TCI was used.The end-tidal carbon diox-ide pressure of every patient was adjusted to three levels, （25±2）mmHg, （35±2）mmHg and （45±2）mmHg, each level was maintained for fifteen minutes.The EEG non-linear parameters of Approximate entropy, Correlation Dimension, Com-plexity were recorded at each level.BP, HR, SpO2, PetCO2 were recorded as usual.Results The end-tidal cardon diox-ide pressure different significantly, and the EEG non-linear parameters of ApEn、Cx changed significantly.Conclusion The variation of PetCO2 between the 25～45 mmHg during the operation produces significant changes in qEEG, which result in the changes of the degree of anaesthsia.This includes significant changes in the EEG non-linear parameters.