Central venous oxygen saturation: from physiology to clinical application

Abstract

Central venous oxygen saturation is a parameter measured via a central venous catheter, situated in the superior vena cava. Its clinical use is supported by the fact that central venous oxygen saturation is a good reflection of mixed venous oxygen saturation, measured via a pulmonary artery catheter, which is a highly invasive device used for assessing haemodynamics. Indeed, the available clinical studies have shown that central venous oxygen saturation and its fluctuations correlate well to mixed venous oxygen saturation and its fluctuations. Thus, it is reasonable to regard central venous oxygen saturation as a valid parameter for assessing the overall balance between the oxygen supply and oxygen consumption of a patient. Measurement of central venous oxygen saturation is interesting in numerous clinical situations in the intensive care unit; however, workers in this department must be aware of the subtleties, limitations, and issues when interpreting this type of results.