Cockroft Gault Calculator Adjusted Body Weight

Cockroft Gault Equation with Adjusted Body Weight:

\[ CrCl (mL/min) = \frac{(140 - age) \times AdjBW \times (0.85 \text{ if female})}{72 \times SCr} \]

Age:

years

Adjusted Body Weight (AdjBW):

Gender:

Serum Creatinine (SCr):

mg/dL

Creatinine Clearance (CrCl):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Cockroft Gault Equation with Adjusted Body Weight?

The Cockroft Gault equation estimates creatinine clearance (CrCl) from age, adjusted body weight, gender, and serum creatinine. Using adjusted body weight provides more accurate results in obese patients compared to using actual body weight.

2. How Does the Calculator Work?

The calculator uses the Cockroft Gault equation with adjusted body weight:

\[ CrCl (mL/min) = \frac{(140 - age) \times AdjBW \times (0.85 \text{ if female})}{72 \times SCr} \]

Where:

\( age \) — Age in years
\( AdjBW \) — Adjusted body weight in kg
0.85 — Female multiplier
\( SCr \) — Serum creatinine (mg/dL)

Explanation: The equation estimates creatinine clearance, which correlates with glomerular filtration rate, using demographic and laboratory values with adjustment for body composition.

3. Importance of CrCl Calculation

Details: Accurate creatinine clearance estimation is crucial for medication dosing, particularly for drugs that are renally eliminated, and for assessing kidney function in clinical practice.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What is adjusted body weight and when should it be used?
A: Adjusted body weight is used in obese patients to avoid overestimation of CrCl. It's calculated as: AdjBW = IBW + 0.4 × (ABW - IBW), where IBW is ideal body weight.

Q2: How does this differ from standard Cockroft Gault?
A: Standard Cockroft Gault uses actual body weight, while this version uses adjusted body weight which is more appropriate for obese patients.

Q3: What are normal CrCl values?
A: Normal CrCl is approximately 90-120 mL/min for young adults, decreasing with age. Values below 60 mL/min indicate impaired kidney function.

Q4: When should adjusted body weight be used?
A: Adjusted body weight should be used for obese patients (typically BMI > 30 kg/m²) to provide more accurate drug dosing estimates.

Q5: Are there limitations to this equation?
A: The equation may be less accurate in elderly patients, those with extreme muscle mass, amputees, and patients with rapidly changing kidney function.