eGFR Calculator MedCalc

CKD-EPI Equation:

\[ eGFR = 142 \times \min(Scr/\kappa, 1)^\alpha \times \max(Scr/\kappa, 1)^{-1.200} \times 0.9938^{age} \times (1.012 \text{ if female}) \]

Estimated GFR (eGFR):

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1. What is the eGFR Calculator MedCalc?

The eGFR Calculator MedCalc estimates glomerular filtration rate (GFR) using the CKD-EPI equation with specific coefficients optimized for clinical use. It calculates kidney function from serum creatinine, age, and gender.

2. How Does the Calculator Work?

The calculator uses the CKD-EPI equation:

\[ eGFR = 142 \times \min(Scr/\kappa, 1)^\alpha \times \max(Scr/\kappa, 1)^{-1.200} \times 0.9938^{age} \times (1.012 \text{ if female}) \]

Where:

\( Scr \) — Serum creatinine (mg/dL)
\( \kappa \) — 0.7 (female) or 0.9 (male)
\( \alpha \) — -0.241 (female) or -0.302 (male)
\( age \) — Age in years
1.012 — Female multiplier

Explanation: This equation provides a more precise estimation of kidney function across different demographic groups using optimized coefficients.

3. Importance of eGFR Calculation

Details: Accurate GFR estimation is essential for diagnosing chronic kidney disease, monitoring disease progression, and determining appropriate medication dosages based on renal function.

4. Using the Calculator

Tips: Enter serum creatinine in mg/dL, age in years, and select gender. Ensure all values are valid (creatinine > 0, age between 1-120 years) for accurate results.

5. Frequently Asked Questions (FAQ)

Q1: What makes this calculator different from standard CKD-EPI?
A: This calculator uses specific coefficients (142, -1.200, 0.9938, 1.012) optimized for clinical accuracy in the MedCalc implementation.

Q2: What are the normal eGFR ranges?
A: Normal eGFR is typically ≥90 mL/min/1.73m². Values between 60-89 may indicate mild kidney impairment, while values below 60 for 3+ months suggest chronic kidney disease.

Q3: When is the best time to measure creatinine?
A: Morning fasting samples are preferred, but random samples are acceptable. Avoid testing after high-protein meals or intense physical activity.

Q4: Are there limitations to this calculation?
A: The equation may be less accurate in elderly patients, those with extreme body weights, amputees, pregnant women, and individuals with rapidly changing kidney function.

Q5: Can this calculator be used for drug dosing?
A: While useful for estimating renal function, for precise drug dosing in critical medications, measured GFR methods may be required in specific patient populations.