[心脏直视手术后患者的氧代谢——体外循环对氧代谢的影响]

[Oxygen economy in patients after open heart surgery--effects of cardiopulmonary bypass on oxygen metabolism].

作者信息

Utoh J, Miyauchi Y, Goto H, Obayashi H, Hirata T

机构信息

First Department of Surgery, Kumamoto University School of Medicine, Japan.

出版信息

Nihon Kyobu Geka Gakkai Zasshi. 1995 Feb;43(2):196-9.

PMID:7714383

Abstract

The relationship between oxygen delivery (DO2) and oxygen consumption (VO2) was studied in thirty patients who underwent open heart surgery. Delivery dependent consumption was observed for the first 48 hours after the surgery even DO2 was in a physiological range (> 300 ml/min/m2). VO2 decreased in proportion to a decrease in DO2 (VO2 = 0.132 x DO2 + 87.9, R = 0.616, p < 0.001). Oxygen extraction rate (ER = VO2/DO2) increased also in proportion to a decrease in DO2 (ER = -0.385 x DO2 + 51.8, R = -0.722, p < 0.001). These results suggest that tissue oxygen demand in the early postoperative period is higher than physiological conditions. Factors which directly influenced ER were cardiac index (CI) and hemoglobin (Hb) as expressed in the following formulas; ER = -6.05 x CI + 51.6 (R = -0.592, p < 0.001), ER = -2.02 x Hb + 56.7 (R = -0.414, p < 0.001). This indicates that hypoperfusion and anemia deteriorate oxygen metabolism in the early postoperative period. As a monitor of oxygen demand, oxygen saturation of mixed venous blood (SvO2) was an useful parameter to indicate the ER (ER = -0.872 x SvO2 + 91.9, R = -0.969, p < 0.001).

摘要

对30例接受心脏直视手术的患者的氧输送（DO2）与氧消耗（VO2）之间的关系进行了研究。术后最初48小时观察到存在氧输送依赖型氧消耗，即使DO2处于生理范围（>300 ml/min/m2）。VO2随DO2的降低而成比例下降（VO2 = 0.132×DO2 + 87.9，R = 0.616，p < 0.001）。氧摄取率（ER = VO2/DO2）也随DO2的降低而成比例增加（ER = -0.385×DO2 + 51.8，R = -0.722，p < 0.001）。这些结果表明术后早期组织氧需求高于生理状况。直接影响ER的因素是心脏指数（CI）和血红蛋白（Hb），如下列公式所示：ER = -6.05×CI + 51.6（R = -0.592，p < 0.001），ER = -2.02×Hb + 56.7（R = -0.414，p < 0.001）。这表明术后早期低灌注和贫血会使氧代谢恶化。作为氧需求的监测指标，混合静脉血氧饱和度（SvO2）是指示ER的有用参数（ER = -0.872×SvO2 + 91.9，R = -0.969，p < 0.001）。