1. What is the Cockcroft-Gault Equation?

The Cockcroft-Gault equation estimates creatinine clearance (CrCl) from serum creatinine, age, weight, and gender. It is widely used in the UK and many other countries for drug dosing adjustments and assessing renal function.

2. How Does the Calculator Work?

The calculator uses the Cockcroft-Gault equation:

Where:

• \( CrCl \) — Creatinine clearance (mL/min)
• \( Age \) — Age in years
• \( Weight \) — Body weight in kilograms
• \( SCr \) — Serum creatinine (mg/dL)
• 0.85 — Female multiplier

Explanation: The equation estimates the rate at which creatinine is cleared from the blood by the kidneys, providing an approximation of glomerular filtration rate.

3. Importance of CrCl Calculation

Details: Creatinine clearance is essential for drug dosing adjustments in patients with renal impairment, assessing kidney function, and monitoring renal disease progression.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: Why is Cockcroft-Gault used in the UK?
A: Cockcroft-Gault is well-established, widely validated, and commonly referenced in UK drug formularies and clinical guidelines for dose adjustment.

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

Q3: When should ideal body weight be used?
A: For obese patients (BMI > 30), ideal body weight may be used instead of actual weight to avoid overestimation of renal function.

Q4: Are there limitations to this equation?
A: Less accurate in elderly, malnourished, obese patients, and those with unstable renal function or extreme muscle mass.

Q5: How does this differ from eGFR?
A: CrCl estimates actual creatinine clearance, while eGFR estimates glomerular filtration rate standardized to body surface area.