IT Quiz Answer – Jan 9, 2025

Here is the answer to our weekly Intelligent Thursday quiz!

Lorrel E.B. Toft, MD
Lorrel E.B. Toft, MD
9th Dec 2024 • 1m read

Pop Quiz: January 9, 2025

Compared to a healthy person, what changes in mixed venous oxygen saturation (SvO2) and cardiac output (CO) would you expect in a patient with cardiogenic shock?

A. Increased SvO2, decreased CO

B. Decreased SvO2, decreased CO

C. Increased SvO2, increased CO

D. Decreased SvO2, increased CO

 

Check your answer!

The correct answer is B. Decreased SvO2, decreased CO

 Explanation:

Remember that low cardiac output is the primary insult in cardiogenic shock.

Mixed venous O2 saturation is a measure of tissue oxygen extraction, which is a surrogate measure of cardiac output.

When the cardiac output is low as in cardiogenic shock, the blood has longer to circulate around the body, giving the tissues more time to extract oxygen. Plus, the tissues are hungry for oxygen. 

So SvO2 and CO must go in the same direction. So in a patient with decreased CO, you can also predict their SvO2 will be decreased.