Which parameter is cardiac output adjusted for body size?

Which parameter is cardiac output adjusted for body size?

• A. Cardiac index
• B. Cardiac output
• C. MAP
• D. CVP

Answer: (A)

Cardiac index is the measure used when you want to compare cardiac performance across patients of different sizes. It normalizes cardiac output to body size, typically body surface area, with the formula CI = CO / BSA. This lets you assess how well the heart is meeting the body's perfusion needs independent of how big or small the patient is, which is especially important in neonates and children who vary widely in size. Cardiac output alone can look higher in a larger patient simply due to size, even if perfusion relative to body demand isn’t better. By indexing to body size, you get a true sense of cardiac performance per unit of body mass. The other measures—mean arterial pressure and central venous pressure—reflect pressure and preload aspects of circulation, not how much cardiac output is being delivered relative to body size, and cardiac output itself isn’t adjusted for size.

Cardiac index is the measure used when you want to compare cardiac performance across patients of different sizes. It normalizes cardiac output to body size, typically body surface area, with the formula CI = CO / BSA. This lets you assess how well the heart is meeting the body's perfusion needs independent of how big or small the patient is, which is especially important in neonates and children who vary widely in size. Cardiac output alone can look higher in a larger patient simply due to size, even if perfusion relative to body demand isn’t better. By indexing to body size, you get a true sense of cardiac performance per unit of body mass. The other measures—mean arterial pressure and central venous pressure—reflect pressure and preload aspects of circulation, not how much cardiac output is being delivered relative to body size, and cardiac output itself isn’t adjusted for size.