1. What is Bladder Volume Calculation?

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

2. How Does the Calculator Work?

The calculator uses the bladder volume formula:

Where:

• \( Length \) — Maximum longitudinal diameter (cm)
• \( Width \) — Maximum transverse diameter (cm)
• \( Height \) — Maximum anterior-posterior diameter (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 helps diagnose urinary retention, monitor post-void residuals, assess bladder function, and guide catheterization decisions.

4. Using the Calculator

Tips: Enter all three dimensions in centimeters as measured by ultrasound. Measurements should be taken at maximum bladder distension for most accurate results.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: The formula has about ±15% accuracy compared to actual catheterized volumes in most patients.

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

Q3: When is this calculation most useful?
A: It's particularly valuable for assessing post-void residual volumes and monitoring patients with urinary retention.

Q4: Are there limitations to this method?
A: Accuracy decreases with irregularly shaped bladders or when measurements aren't taken at maximal distension.

Q5: What's considered a significant post-void residual?
A: Generally, >100 mL is considered significant, though clinical context is important.