1. What is the Cockcroft-Gault Equation?

The Cockcroft-Gault equation estimates creatinine clearance (CrCl) which correlates with glomerular filtration rate (GFR). It's widely used for drug dosing adjustments in patients with kidney impairment.

2. How Does the Calculator Work?

The calculator uses the Cockcroft-Gault equation:

Where:

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

Explanation: The equation estimates how quickly creatinine is cleared from the blood, which reflects kidney function.

3. Importance of CrCl Calculation

Details: CrCl estimation is crucial for adjusting medication dosages in patients with impaired kidney function to prevent toxicity or underdosing.

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 Cockcroft-Gault instead of eGFR?
A: Many drug dosing guidelines specifically reference CrCl from Cockcroft-Gault rather than eGFR from other equations.

Q2: What are normal CrCl values?
A: Normal is approximately 90-120 mL/min for young adults, decreasing with age. Below 60 may indicate impaired kidney function.

Q3: Should actual or ideal body weight be used?
A: For obese patients, some guidelines recommend using ideal body weight or adjusted body weight rather than actual weight.

Q4: Are there limitations to this equation?
A: Less accurate in very old, very young, malnourished, amputees, or those with rapidly changing kidney function.

Q5: When is measured CrCl preferred?
A: For precise drug dosing in critical situations or when the equation may be inaccurate (extremes of body composition).