Using the Cockcroft-Gault equation, estimate CrCl for a 30-year-old male weighing 80 kg with serum creatinine 2.0 mg/dL.

Using the Cockcroft-Gault equation, estimate CrCl for a 30-year-old male weighing 80 kg with serum creatinine 2.0 mg/dL.

• A. 55 mL/min
• B. 60 mL/min
• C. 61 mL/min
• D. 70 mL/min

Answer: (C)

This question tests using the Cockcroft-Gault equation to estimate creatinine clearance. For males, CrCl = [(140 − age) × weight] / (72 × serum creatinine). Plugging in the values: age 30 → (140 − 30) = 110; weight = 80 kg; serum creatinine = 2.0 mg/dL. Numerator: 110 × 80 = 8,800. Denominator: 72 × 2.0 = 144. CrCl ≈ 8,800 / 144 ≈ 61.1 mL/min. So the estimated creatinine clearance is about 61 mL/min. This is a straightforward application of the formula using actual body weight without sex adjustment beyond the male default. (Note: the value is not normalized to a standard body surface area unless you explicitly convert it.)

This question tests using the Cockcroft-Gault equation to estimate creatinine clearance. For males, CrCl = [(140 − age) × weight] / (72 × serum creatinine).

Plugging in the values: age 30 → (140 − 30) = 110; weight = 80 kg; serum creatinine = 2.0 mg/dL. Numerator: 110 × 80 = 8,800. Denominator: 72 × 2.0 = 144. CrCl ≈ 8,800 / 144 ≈ 61.1 mL/min.

So the estimated creatinine clearance is about 61 mL/min. This is a straightforward application of the formula using actual body weight without sex adjustment beyond the male default. (Note: the value is not normalized to a standard body surface area unless you explicitly convert it.)