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
• \( weight \) — Body weight in kg
• \( SCr \) — Serum creatinine (mg/dL)
• 0.85 — Female multiplier

Explanation: The equation estimates creatinine clearance which correlates with glomerular filtration rate (GFR), accounting for age-related decline in kidney function and gender differences.

3. Importance of CrCl Calculation

Details: CrCl estimation is crucial for medication dosing adjustments, particularly for drugs that are renally excreted or nephrotoxic.

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 1-120, weight >0, SCr >0).

5. Frequently Asked Questions (FAQ)

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

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

Q3: Should actual or ideal body weight be used?
A: For obese patients, some clinicians use adjusted body weight or ideal body weight to avoid overestimation.

Q4: Are there limitations to this equation?
A: Less accurate in extremes of age, weight, muscle mass, and in patients with rapidly changing kidney function.

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