体外循环中不同双频指数下丙泊酚或依托咪酯对脑氧代谢的影响

目的讨论在浅低温体外循环(extracorporeal circulation,ECC)术中,脑电双频指数(BIS)抑制程度不同时丙泊酚或依托咪酯对脑氧代谢的影响。方法18例ECC下行冠状动脉旁路移植术患者,随机分丙泊酚组和依托咪酯组。术中给予大剂量丙泊酚或依托咪酯,使BIS降低至0。分别在给药前、后及BIS下降到不同程度时,抽取颈内静脉球部血液和桡动脉血液计算脑氧摄取率(COE)。结果两组在各个时间点的COE均无差异。结论在浅低温ECC中丙泊酚或依托咪酯对BIS的抑制程度与剂量呈正相关;在浅低温ECC中使BIS下降到0时的大剂量丙泊酚或依托咪酯对COE无影响。

The Effects of Propofol or Etomidate on Cerebral Oxygen Extraction under Different Bispectral Index

OBJECTIVE To evaluate and compare the effects of high doses propofol or etomidate on cerebral oxygen extraction(COE) during light hypothermic extracorporeal circulation(ECC) in selective coronary artery bypass graft(CABG) patients.METHODS Patients(n=18) were randomly entered into one of the two groups: propofol or Eetomidate group.All the study drugs were given through the subclavicular vein after aotic artery clamping until the bispectral indx(BIS)decreasing to zero.The blood gas samples were drawn from the radial artery and jugular venous bulb before the drugs were given(baseline point),and when BIS was inhibited to 75%,50%,25% and 0%(BIS=0) of baseline point.The COE was calculated and hemodynamic data were recorded. RESULTS There was no difference of COE among the groups at every time point.CONCLUSION The changes of BIS caused by 1%propofol or 0.2% etomidte was negatively correlative with their doses during light hypothemic ECC.All the study drugs can reduce BIS to zero.The high doses of propofol or etomidate of BIS zero can not change COE.