In the creatinine clearance calculation, which constant is used to adjust for body surface area?

In the creatinine clearance calculation, which constant is used to adjust for body surface area?

• A. 1.0
• B. 1.73
• C. 0.9
• D. 2.0

Answer: (B)

Normalizing renal function tests to a standard body size lets us compare creatinine clearance across people with different physiques. In practice, creatinine clearance values are adjusted to a body surface area of 1.73 m^2. This is done by multiplying the calculated clearance by the ratio 1.73 divided by the individual’s actual body surface area (CrCl × 1.73 / BSA). The fixed reference constant used in this adjustment is 1.73 m^2. Using this standard allows reporting CrCl as mL/min per 1.73 m^2, making values meaningful across patients of varying sizes.

Normalizing renal function tests to a standard body size lets us compare creatinine clearance across people with different physiques. In practice, creatinine clearance values are adjusted to a body surface area of 1.73 m^2. This is done by multiplying the calculated clearance by the ratio 1.73 divided by the individual’s actual body surface area (CrCl × 1.73 / BSA). The fixed reference constant used in this adjustment is 1.73 m^2. Using this standard allows reporting CrCl as mL/min per 1.73 m^2, making values meaningful across patients of varying sizes.