Calculate eGFR from Creatinine and BUN

CKiD U25 Equation:

\[ eGFR = 39.8 \times \left(\frac{Height}{Scr}\right)^{0.456} \times \left(\frac{1.8}{Scys}\right)^{0.418} \times \left(\frac{30}{BUN}\right)^{0.079} \times (1.076 \text{ if male}) \times \left(\frac{Height}{1.4}\right)^{0.179} \]

Height:

Serum Creatinine (Scr):

mg/dL

Blood Urea Nitrogen (BUN):

mg/dL

Gender:

Estimated GFR (eGFR):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the CKiD U25 Equation?

The CKiD U25 (Chronic Kidney Disease in Children Under 25) equation estimates glomerular filtration rate (GFR) from serum creatinine, blood urea nitrogen (BUN), height, and gender. This pediatric equation provides accurate assessment of kidney function in children and young adults up to 25 years of age.

2. How Does the Calculator Work?

The calculator uses the CKiD U25 equation:

Where:

\( Height \) — Height in meters
\( Scr \) — Serum creatinine (mg/dL)
\( BUN \) — Blood urea nitrogen (mg/dL)
1.076 — Male multiplier
1.4 — Reference height value

Explanation: The equation incorporates height to account for body size, creatinine for muscle metabolism, and BUN for protein metabolism, providing comprehensive pediatric kidney function assessment.

3. Importance of Pediatric eGFR Calculation

Details: Accurate GFR estimation in pediatric populations is crucial for diagnosing chronic kidney disease, monitoring disease progression, and guiding appropriate medication dosing in growing children.

4. Using the Calculator

Tips: Enter height in meters, serum creatinine and BUN in mg/dL, and select gender. All values must be valid positive numbers. This equation is specifically designed for patients aged 1-25 years.

5. Frequently Asked Questions (FAQ)

Q1: What age range is this equation designed for?
A: The CKiD U25 equation is specifically validated for children and young adults aged 1-25 years.

Q2: Why include height in the calculation?
A: Height accounts for body surface area and growth in pediatric patients, providing more accurate GFR estimation than creatinine alone.

Q3: What are normal eGFR values for children?
A: Normal pediatric eGFR values vary by age and body size, but generally range from 90-140 mL/min/1.73m² in healthy children.

Q4: When should this equation not be used?
A: Avoid in patients with amputations, severe malnutrition, muscle wasting diseases, or rapidly changing kidney function.

Q5: How does this differ from adult eGFR equations?
A: Pediatric equations incorporate height and are validated in younger populations, while adult equations typically use age, gender, and race factors.