Calculate Creatinine Clearance UK

Cockcroft-Gault Equation (UK units):

\[ CrCl = \frac{(140 - Age) \times Weight \times 0.85 \text{ (if female)}}{72 \times SCr} \]

Age:

years

Weight:

Serum Creatinine (SCr):

mg/dL

Gender:

Creatinine Clearance (CrCl):

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1. What is the Cockcroft-Gault Equation?

The Cockcroft-Gault equation estimates creatinine clearance (CrCl) from serum creatinine, age, weight, and gender. It is widely used in clinical practice, particularly for drug dosing adjustments in patients with renal impairment.

2. How Does the Calculator Work?

The calculator uses the Cockcroft-Gault equation (UK units):

\[ CrCl = \frac{(140 - Age) \times Weight \times 0.85 \text{ (if female)}}{72 \times SCr} \]

Where:

\( Age \) — Age in years
\( Weight \) — Body weight in kilograms
\( SCr \) — Serum creatinine in mg/dL
\( 0.85 \) — Correction factor for female gender

Explanation: The equation estimates creatinine clearance based on demographic and laboratory parameters, accounting for age-related decline in renal function and gender differences.

3. Importance of Creatinine Clearance Calculation

Details: Creatinine clearance is essential for assessing renal function, guiding drug dosing (especially for renally eliminated medications), and monitoring kidney disease progression.

4. Using the Calculator

Tips: Enter age in years, weight in kilograms, serum creatinine in mg/dL, and select gender. All values must be valid (age 1-120 years, weight > 0 kg, creatinine > 0 mg/dL).

5. Frequently Asked Questions (FAQ)

Q1: What are normal creatinine clearance values?
A: Normal CrCl is approximately 95-125 mL/min for young adult men and 85-115 mL/min for young adult women, declining with age.

Q2: Why use Cockcroft-Gault instead of eGFR?
A: Cockcroft-Gault is still preferred for drug dosing adjustments in many clinical guidelines, while eGFR is primarily used for CKD staging.

Q3: What are the limitations of this equation?
A: Less accurate in extremes of age, obesity, malnutrition, amputees, and patients with rapidly changing renal function or muscle mass.

Q4: Should ideal body weight be used?
A: For obese patients, some guidelines recommend using ideal body weight rather than actual weight to avoid overestimating CrCl.

Q5: Is this equation validated for all populations?
A: The equation was derived primarily from Caucasian populations and may require validation for other ethnic groups.