1. What is Urinary Creatinine Clearance?

Urinary creatinine clearance is a measure of the kidney's ability to filter and remove creatinine from the blood. It provides a direct measurement of glomerular filtration rate (GFR) and is considered more accurate than estimated GFR equations when properly collected.

2. How Does the Calculator Work?

The calculator uses the creatinine clearance equation:

Where:

• \( U_{cr} \) — Urinary creatinine concentration (mg/dL)
• \( Urine\ Volume \) — Total 24-hour urine volume (mL)
• \( P_{cr} \) — Plasma creatinine concentration (mg/dL)
• \( 1440 \) — Minutes in 24 hours

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

3. Importance of Creatinine Clearance Calculation

Details: 24-hour creatinine clearance is considered the gold standard for measuring GFR in clinical practice. It's essential for accurate assessment of kidney function, drug dosing adjustments, and monitoring kidney disease progression.

4. Using the Calculator

Tips: Enter urinary creatinine in mg/dL, 24-hour urine volume in mL, and plasma creatinine in mg/dL. Ensure all values are from the same 24-hour collection period for accurate results.

5. Frequently Asked Questions (FAQ)

Q1: Why is 24-hour urine collection important?
A: 24-hour collection accounts for diurnal variations in creatinine excretion and provides the most accurate measurement of true GFR.

Q2: What are normal creatinine clearance values?
A: Normal range is approximately 90-130 mL/min for men and 80-125 mL/min for women, varying with age and body size.

Q3: How should 24-hour urine be collected?
A: Discard first morning urine, then collect all urine for next 24 hours including next morning's first void. Keep refrigerated during collection.

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

Q5: When is creatinine clearance preferred over eGFR?
A: In patients with extremes of age, muscle mass, amputations, or when precise drug dosing is critical.