混合静脉血氧饱和度与心脏指数的关系

Relationship between Mixed Venous Oxygen Saturation and Cardiac Index

对３０例心脏换瓣术病人术后同时监测混合静脉血氧饱和度（ＳＶＯ２）与心脏指数（ＣＩ），二者呈非线性相关，相关系数０６６，当校正了个体之间氧耗（ＶＯ２）和血红蛋白值（Ｈｂ）的差异后，其相关系数为０９４。运用直线回归法分析个体资料，Ａ、Ｂ组病人平均ＣＩ和ＳＶＯ２分别为２４５Ｌ·ｍｉｎ－１·ｍ－２和６１％，３３０Ｌ·ｍｉｎ－１·ｍ－２和７３４％，其平均斜率和相关系数分别是１８２和０８６，０８８和０２０。故认为一组病人ＳＶＯ２与ＣＩ关系的非线性相关系数高低取决于其ＶＯ２和Ｈｂ值的均一性，ＳＶＯ２作为某一病人监测ＣＩ变化的作用取决于ＳＶＯ２和ＣＩ的状态。

hirty patients,undergoing cardiac valve replacement surgery,served as subjects.A nonlinear relationship between mixed venous oxygen saturation (SVO2) and cardiac index (CI) was observed .Its correlation coeffecient was 0.66,and became 0.94 after normalizing individual differences in hemoglobin (Hb) and oxygen consumption (VO_2);Further analysis of individual data was performed using linear regression,and the slopes and correlation coeffecients ranged from17.2 to 50.2 and from0.99 to 1.00,respectively.The mean slope and correlation coeffecient in 19 patients with mean CI and SVO2 of 2.45 L·min-1·m-2 and 61 percent were 182 and 086,respectively,while in the rest of the patients with mean CI and SVO2 of 3.30 L·min-1·m-2 and 734 percent were only 088 and 020, respectively.The nonlinear correlation coeffecient of CI and SVO2 in a group of patients is dependent on the homogeneity of VO_2 and Hb concentration; The ability of SVO2 reflecting CI in a patient is dependent on the hemodynamic status of the patient .