Using the Cockcroft-Gault equation, estimate CrCl for a 40-year-old female weighing 55 kg with serum creatinine 1.4 mg/dL.

Using the Cockcroft-Gault equation, estimate CrCl for a 40-year-old female weighing 55 kg with serum creatinine 1.4 mg/dL.

• A. 40 mL/min
• B. 46 mL/min
• C. 50 mL/min
• D. 60 mL/min

Answer: (B)

The Cockcroft-Gault equation estimates creatinine clearance using age, weight, sex, and serum creatinine, with a 0.85 factor for females. The formula is CrCl = (140 − age) × weight × 0.85 / (72 × SCr). Plugging in the numbers: (140 − 40) = 100, weight = 55 kg, SCr = 1.4 mg/dL, and applying the female factor gives numerator 100 × 55 × 0.85 = 4675. Denominator is 72 × 1.4 = 100.8. So CrCl ≈ 4675 / 100.8 ≈ 46.3 mL/min, which rounds to about 46 mL/min. This estimate aligns with the closest option, around 46 mL/min.

The Cockcroft-Gault equation estimates creatinine clearance using age, weight, sex, and serum creatinine, with a 0.85 factor for females. The formula is CrCl = (140 − age) × weight × 0.85 / (72 × SCr).

Plugging in the numbers: (140 − 40) = 100, weight = 55 kg, SCr = 1.4 mg/dL, and applying the female factor gives numerator 100 × 55 × 0.85 = 4675. Denominator is 72 × 1.4 = 100.8. So CrCl ≈ 4675 / 100.8 ≈ 46.3 mL/min, which rounds to about 46 mL/min.

This estimate aligns with the closest option, around 46 mL/min.