Where is SvO2 measured?

Where is SvO2 measured?

• A. In the superior vena cava via a central venous catheter
• B. In the pulmonary artery using a Swan-Ganz catheter
• C. In the inferior vena cava with a catheter
• D. In the right atrium with a central venous catheter

Answer: (B)

SvO2 is mixed venous oxygen saturation, reflecting the global balance between oxygen delivery and consumption. To obtain a truly mixed venous sample, you need blood that has returned from all parts of the body. That reliable sample comes from the distal port of a pulmonary artery catheter (Swan-Ganz) positioned in the pulmonary artery, where blood has mixed from the entire systemic circulation before it heads to the lungs for oxygenation. Sampling from central venous sites such as the superior or inferior vena cava or from the right atrium yields regional venous saturations (like ScvO2) and does not represent the whole-body mix. Hence, SvO2 is measured in the pulmonary artery with a Swan-Ganz catheter.

SvO2 is mixed venous oxygen saturation, reflecting the global balance between oxygen delivery and consumption. To obtain a truly mixed venous sample, you need blood that has returned from all parts of the body. That reliable sample comes from the distal port of a pulmonary artery catheter (Swan-Ganz) positioned in the pulmonary artery, where blood has mixed from the entire systemic circulation before it heads to the lungs for oxygenation. Sampling from central venous sites such as the superior or inferior vena cava or from the right atrium yields regional venous saturations (like ScvO2) and does not represent the whole-body mix. Hence, SvO2 is measured in the pulmonary artery with a Swan-Ganz catheter.