1. What is the Cockroft-Gault Equation?

The Cockroft-Gault equation estimates creatinine clearance (CrCl) from serum creatinine, age, weight, and sex. It is commonly used for drug dosing adjustments in patients with kidney impairment.

2. How Does the Calculator Work?

The calculator uses the Cockroft-Gault equation:

Where:

• \( age \) — Age in years
• \( weight \) — Weight in kilograms
• \( SCr \) — Serum creatinine (mg/dL)
• 0.85 — Female multiplier

Explanation: The equation estimates creatinine clearance which correlates with glomerular filtration rate (GFR), with adjustment for gender differences in muscle mass.

3. Importance of CrCl Calculation

Details: CrCl estimation is crucial for adjusting medication dosages in patients with kidney impairment, particularly for drugs that are renally excreted.

4. Using the Calculator

Tips: Enter age in years, weight in kg, serum creatinine in mg/dL, and select gender. All values must be valid (age between 1-120, weight > 0, SCr > 0).

5. Frequently Asked Questions (FAQ)

Q1: Why use Cockroft-Gault instead of CKD-EPI?
A: Cockroft-Gault is traditionally used for drug dosing, while CKD-EPI is better for diagnosing and staging chronic kidney disease.

Q2: What are normal CrCl values?
A: Normal is approximately 95-125 mL/min for men and 85-115 mL/min for women, decreasing with age.

Q3: Should ideal or actual body weight be used?
A: For obese patients, consider using ideal body weight or adjusted body weight for more accurate estimation.

Q4: Are there limitations to this equation?
A: Less accurate in extremes of age/weight, amputees, pregnant women, and those with rapidly changing kidney function or very low muscle mass.

Q5: How often should CrCl be recalculated?
A: Recalculate when there are significant changes in weight, creatinine, or clinical status.