休克或心功能不全病人动脉血气分析是反应机体酸碱平衡的重要指标,但有时单纯靠动脉血气分析并不能很好、全面地反应组织的血流灌注情况和缺氧程度。混合静脉血内的PCO2在一定情况下可以反应组织的血流/氧需比,但采集风险较大、费用高,中心静脉血与混合静脉血的酸碱指标近似,采集容易、经济,可以用来代替混合静脉血[1]。本文用 Arterial blood gas analysis in patients with shock or cardiac insufficiency is an important indicator of the acid-base balance of the body, but sometimes simply by arterial blood gas analysis does not respond well to the full extent of tissue perfusion and hypoxia. Mixed venous blood PCO2 can reflect the tissue blood flow / oxygen ratio under certain circumstances, but the collection risk is high, the cost is high, the central venous blood and mixed venous blood have similar acid-base indexes, and the collection is easy and economical. Instead of mixed venous blood [1]. This article use