Q Where is Svo2 (percentage of oxygen saturation in the pulmonary arterial blood) measured in the body?
Svo2 is measured in the pulmonary artery (PA), where venous blood mixes after circulating through the superior and inferior vena cavae, coronary sinuses, and the chambers in the right side of the heart. Although Svo2 is the percentage of oxygen saturation in the pulmonary arterial blood, Svo2 actually represents an average of all the venous oxygen saturations of the various organs and tissues.1
Q: Describe the technology used to measure Svo2.
The components of an Svo2 monitoring system include a flow-directed thermodilution PA catheter that has conventional hemodynamic monitoring capabilities in addition to fiber optics for transmitting light (Figure 1), an optical module that contains a light-emitting source and a photodetector, and a microprocessor to analyze reflected light....