冠状动脉旁路移植术后氧代谢监测的初步探讨

Changes of postoperative oxygenic metabolism in patients undergone coronary artery bypass graft

目的:探讨冠状动脉旁路移植(CABG)术后氧代谢的变化及临床意义。方法:回顾性分析45例CABG患者,监测术后1、4、12、24、48h氧供(DO2)、氧耗(VO2)、氧摄取值(ERO2)。结果:CABG术后1hDO2最低,为362.7mL/(min·m2),术后4、12h分别为395.8mL/(min·m2)、433.3mL/(min·m2),低于术后24h的467.3mL/(min·m2),术后24h后基本稳定。术后12hVO2最高,为144.3mL/(min·m2)。术后1hERO2最高,为35.1%,术后12hERO2为33.3%,略低于术后1h时,术后24h降低为31.4%。结论:CABG术后1～4h时组织处于缺氧状态,应加强氧供。术后存在病理性氧供依赖现象,氧供临界值为362.7～395.8mL/(min·m2)。CABG术后早期机体处于相对缺氧状态,此时应采用综合措施保证供氧和降低氧耗。

Objective To observe the changes of postoperative oxygenic metabolism in patients undergone coronary artery bypass graft（CABG） and to evaluate its clinical significance. Methods Forty-five patients （37 male, 8 female） undergoing CABG, aged from 41 to 69 years old, were randomized selected. The oxygen delivery, oxygen consumption, and oxygen extraction were monidored at 1, 4, 12, 24 and 48 hours postoperatively. Results After CABG, the postoperative oxygen delivery decreased firstly, was the lowest [362.7 mL/（min · m^2） ]at 1 h, and then began to restep up and trended to stable at 24 h. The postoperative oxygen consumption was increased and reached to the peak at 12 h[144.3 mL/ （min · m^2） ] . The postoperative oxygen extraction was the highest （35.1%） at 1 h, and then began to step down and reached to the bottom （30. 1% ） . Conclusion After CABG, hypoxia keeps on existing, showing a pathologic oxygen supply dependency, its critical level of oxygen delivery is between 362. 7 mL/（min · m^2） and 395.8 mL/（min · m^2）. It is suggested that oxygen delivery should be increased oxygen consumption should be reduced after CABG, especially at 1 to 4h after surgery.