1. What is Bladder Volume Calculation?

The bladder volume calculation using point-of-care ultrasound (POCUS) estimates urine volume in the bladder. It's commonly used to assess urinary retention, post-void residual volume, and 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
• \( 0.52 \) — Correction factor for bladder shape

Explanation: The formula approximates bladder volume by treating it as an ellipsoid shape and applying a correction factor.

3. Importance of Bladder Volume Measurement

Details: Accurate bladder volume measurement is crucial for diagnosing urinary retention, monitoring post-void residuals, assessing bladder capacity, and guiding catheterization decisions.

4. Using the Calculator

Tips: Enter bladder dimensions in centimeters as measured by ultrasound. All values must be positive numbers. Measurements should be taken in the transverse and sagittal planes.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: The formula has about ±20% accuracy compared to catheterized volumes, making it suitable for clinical estimation but not precise measurement.

Q2: What is a normal bladder volume?
A: Normal bladder capacity is typically 300-500 mL, though this varies with age, gender, and individual factors.

Q3: When is this calculation most useful?
A: Particularly valuable for assessing post-void residual volumes and diagnosing urinary retention in non-invasive way.

Q4: Are there limitations to this method?
A: Less accurate for very small or very large volumes, irregularly shaped bladders, or when proper ultrasound technique isn't used.

Q5: What's the clinical significance of post-void residual?
A: Residual volumes >100 mL often indicate incomplete emptying, while >300 mL typically requires intervention.