1. What is Creatinine Clearance?

Creatinine clearance is a measure of the glomerular filtration rate (GFR) calculated from urine and plasma creatinine concentrations. It provides a direct assessment of kidney function by measuring how effectively the kidneys clear creatinine from the blood.

2. How Does the Calculator Work?

The calculator uses the creatinine clearance formula:

Where:

• \( U_{cr} \) — Urine creatinine concentration (mg/dL)
• \( V \) — Urine volume per unit time (mL/min)
• \( P_{cr} \) — Plasma creatinine concentration (mg/dL)

Explanation: This formula calculates the volume of plasma cleared of creatinine per minute, providing a direct measurement of glomerular filtration rate.

3. Importance of Creatinine Clearance

Details: Creatinine clearance is considered the gold standard for assessing kidney function and is particularly useful for drug dosing adjustments, monitoring kidney disease progression, and evaluating transplant function.

4. Using the Calculator

Tips: Enter urine creatinine in mg/dL, urine volume in mL/min, and plasma creatinine in mg/dL. All values must be positive numbers. Ensure proper urine collection timing for accurate results.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between creatinine clearance and eGFR?
A: Creatinine clearance is measured directly from urine and blood samples, while eGFR is estimated using equations based on serum creatinine and demographic factors.

Q2: How long should urine be collected for creatinine clearance?
A: Typically 24-hour urine collection is used, but shorter periods (2-4 hours) can be used with proper timing and documentation.

Q3: What are normal creatinine clearance values?
A: Normal range is approximately 95-125 mL/min for men and 85-115 mL/min for women, varying with age and body size.

Q4: When is creatinine clearance preferred over eGFR?
A: For precise drug dosing, in patients with extreme body sizes, amputees, or when highly accurate GFR measurement is required.

Q5: What factors can affect creatinine clearance results?
A: Incomplete urine collection, meat consumption, exercise, medications, and muscle mass can all influence results.