冠状动脉旁路移植术中连续心排血量及混合静脉血氧饱和度的监测

The monitoring of continuous cardiac output and mixed venous oxygen saturation during coronary artery bypass grafting

目的:观察冠状动脉旁路移植术中连续心排血量和混合静脉血氧饱和度的监测的临床意义及影响因素。方法:50例冠状动脉旁路移植术病人,从颈内静脉放置CCO-SO_2 Swan-Ganz导管,连续监测心排血量和混合静脉血氧饱和度的变化。结果:体外循环前CI最低值为1.1L·min^(-1)·m^(-2),但SO_2均>65%,CO与SO_2无相关性。CPB中有5例SO_2<65%,其中有2例因CO不能满足组织氧合的需要,1例因稀释性贫血;另2例可能因氧耗增加。结论:SO_2监测对判定病情似乎较单一CO监测更有意义。欲维持SO_2在正常范围,必须注意CO、VO_2、Hb和SaO_2四个变量的影响及维持良好的血流动力学。

To evaluate the clinical importance and influencing factors of the monitoring of continuous cardiac output (CCO) and mixed venous oxygen saturation (SvO_2) during coronary artery bypass grafting (CABG). Method: The changes of CCO and SvO_2 were monitored in 50 patients undergoing coronary artery bypass grafting by placement of CCO/SvO_2 Swan-Ganz catheter through right internal jugular vein. Result: The values of SvO_2 measured were more than 65% in all patients, accompanied by relatively low values of CI(the lowest value of CI being 1.1 L·m^(-2). min^(-1), there was no correlation between CCO and SvO_2 before CPB. After CPB, there were five patients having lower SvO_2 (<65%), in 2 cases of whom the CO could not adequately provide oxygen to tissues; in one case lower hemoglobin concentration occured, in the other 2 cases the oxygen consumption might be higher. Conclusion: The SvO_2 is a better guideline to tissue oxygenation than cardiac output in patients with coronary artery disease. It should be no riced that SvO_2 is determined by oxygen consumption,cardiac output,hemoglobin concentration and oxygenation of arterial blood. to maintain stable hemodynamics is very important as well.