1. What is Bladder Volume Calculation?

The bladder volume calculation estimates urine volume in the bladder using ultrasound measurements. It's commonly used to assess post-void residual volume or bladder capacity.

2. How Does the Calculator Work?

The calculator uses the bladder volume formula:

Where:

• \( Length \) — Maximum bladder length in cm
• \( Width \) — Maximum bladder width in cm
• \( Height \) — Maximum bladder height in cm
• \( 0.52 \) — Shape correction factor for ellipsoid volume

Explanation: The formula approximates the bladder as an ellipsoid shape and applies a correction factor to improve accuracy.

3. Importance of Bladder Volume Measurement

Details: Bladder volume measurement helps diagnose urinary retention, assess bladder function, and guide catheterization decisions.

4. Using the Calculator

Tips: Enter all three dimensions in centimeters as measured on ultrasound. Measurements should be taken in orthogonal planes.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is ultrasound bladder volume measurement?
A: The method has about ±15-20% accuracy compared to catheterized volumes, but is non-invasive and clinically useful.

Q2: What is a normal post-void residual volume?
A: Less than 50 mL is generally normal, while >200 mL suggests significant retention.

Q3: When should bladder volume be measured?
A: Common indications include evaluation of urinary retention, monitoring bladder function, and post-void residual assessment.

Q4: Are there alternative formulas?
A: Some use 0.625 instead of 0.52 for different shape assumptions, but 0.52 is most commonly used.

Q5: Can this be used for pediatric patients?
A: Yes, but normal volumes vary significantly with age and body size in children.