1. What is Creatinine Clearance?

Creatinine clearance is a measure of the glomerular filtration rate (GFR) calculated from a 24-hour urine collection and a blood sample. It estimates how well the kidneys are filtering creatinine from the blood.

2. How Does the Calculator Work?

The calculator uses the creatinine clearance formula:

Where:

• \( CrCl \) — Creatinine clearance (mL/min)
• \( UCr \) — Urine creatinine concentration (mg/dL)
• \( V \) — Urine volume collected over 24 hours (mL/24h)
• \( PCr \) — Plasma creatinine concentration (mg/dL)
• \( 1440 \) — Minutes in 24 hours

Explanation: This formula calculates the volume of plasma cleared of creatinine per minute, providing a direct measurement of kidney function.

3. Importance of Creatinine Clearance

Details: Creatinine clearance is crucial for assessing renal function, diagnosing kidney disease, monitoring disease progression, and adjusting medication dosages for drugs excreted by the kidneys.

4. Using the Calculator

Tips: Enter urine creatinine in mg/dL, 24-hour urine volume in mL, and plasma creatinine in mg/dL. All values must be positive numbers obtained from proper 24-hour urine collection and blood testing.

5. Frequently Asked Questions (FAQ)

Q1: Why is 24-hour urine collection necessary?
A: 24-hour collection provides an accurate measurement of total creatinine excretion, which is essential for precise clearance calculation.

Q2: What are normal creatinine clearance values?
A: Normal values are typically 95-125 mL/min for men and 85-115 mL/min for women, but vary with age, muscle mass, and body size.

Q3: How should the 24-hour urine be collected?
A: Start with an empty bladder, collect all urine for 24 hours, keep refrigerated, and record the total volume and collection time.

Q4: What factors can affect creatinine clearance results?
A: Incomplete urine collection, meat consumption, exercise, medications, and muscle mass can all influence results.

Q5: When is creatinine clearance preferred over eGFR?
A: Creatinine clearance is preferred in patients with extremes of age, muscle mass, or when precise measurement is needed for drug dosing.