1. What is the eGFR to CrCl Conversion?

The MDCalc conversion adjusts eGFR (normalized to 1.73m² body surface area) to actual creatinine clearance (CrCl) by accounting for the patient's actual body surface area.

2. How Does the Calculator Work?

The calculator uses the MDCalc conversion formula:

Where:

• \( eGFR \) — Estimated glomerular filtration rate (mL/min/1.73m²)
• \( BSA \) — Body surface area (m²)
• 1.73 — Standard adult BSA value

Explanation: The equation adjusts the standardized eGFR to the patient's actual body size by multiplying by the ratio of their BSA to the standard 1.73m².

3. Importance of CrCl Calculation

Details: While eGFR is used for kidney function assessment, CrCl is often needed for drug dosing adjustments as it represents the actual clearance rate for the individual patient.

4. Using the Calculator

Tips: Enter eGFR in mL/min/1.73m² and BSA in m². Both values must be positive numbers. BSA can be calculated separately using Mosteller or other formulas.

5. Frequently Asked Questions (FAQ)

Q1: Why convert eGFR to CrCl?
A: eGFR is standardized to 1.73m² BSA for comparison, while CrCl represents the actual clearance rate which is important for drug dosing.

Q2: How accurate is this conversion?
A: It provides a reasonable estimate but may not account for all individual variations in creatinine production and excretion.

Q3: When should I use CrCl instead of eGFR?
A: Use CrCl for medication dosing decisions, especially for drugs with narrow therapeutic windows.

Q4: What's the difference between CrCl and eGFR?
A: eGFR is standardized to 1.73m² BSA while CrCl is the actual clearance rate for the patient's body size.

Q5: Can I use this for pediatric patients?
A: This conversion can be used for adults and children, but ensure pediatric-appropriate BSA calculations are used.