1. What is Creatinine Clearance?

Creatinine clearance is a measure of the glomerular filtration rate (GFR) calculated from urine and plasma creatinine concentrations. It represents the volume of plasma cleared of creatinine per minute and is used to assess kidney function.

2. How Does the Calculator Work?

The calculator uses the creatinine clearance formula:

Where:

• \( U_{cr} \) — Urine creatinine concentration (mg/dL)
• \( Urine\ Volume \) — Total urine volume collected (mL)
• \( P_{cr} \) — Plasma creatinine concentration (mg/dL)
• \( Time \) — Collection time in minutes

Explanation: This formula calculates the rate at which creatinine is cleared from the blood by the kidneys, providing an estimate of renal function.

3. Importance of Creatinine Clearance Calculation

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

4. Using the Calculator

Tips: Enter urine creatinine in mg/dL, urine volume in mL, plasma creatinine in mg/dL, and collection time in minutes. All values must be positive numbers. For 24-hour collections, use 1440 minutes.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between creatinine clearance and eGFR?
A: Creatinine clearance is measured using urine and blood samples, while eGFR is estimated from blood creatinine alone using equations like CKD-EPI or MDRD.

Q2: What are normal creatinine clearance values?
A: Normal values are approximately 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 urine be collected for creatinine clearance?
A: A 24-hour urine collection is standard. Start with an empty bladder, collect all urine for 24 hours, and end with a final void at exactly 24 hours.

Q4: What factors can affect creatinine clearance results?
A: Factors include incomplete urine collection, meat consumption, exercise, medications, muscle mass, and hydration status.

Q5: When is creatinine clearance preferred over eGFR?
A: Creatinine clearance is preferred for drug dosing adjustments, in patients with extreme body sizes, amputees, or when precise GFR measurement is needed.