1. What is the Bladder PVR Calculation?

The Bladder Post-Void Residual (PVR) calculation estimates the volume of urine remaining in the bladder after voiding using ultrasound measurements. It's an important diagnostic tool for evaluating urinary retention and bladder dysfunction.

2. How Does the Calculator Work?

The calculator uses the PVR equation:

Where:

• \( Length \) — Bladder length measurement (cm)
• \( Width \) — Bladder width measurement (cm)
• \( Height \) — Bladder height measurement (cm)
• \( 0.52 \) — Correction factor for bladder shape

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

3. Importance of PVR Measurement

Details: PVR measurement helps diagnose urinary retention, assess bladder function, monitor treatment effectiveness, and prevent complications like urinary tract infections.

4. Using the Calculator

Tips: Enter bladder dimensions in centimeters as measured by ultrasound. All values must be positive numbers. Measurements should be taken immediately after voiding.

5. Frequently Asked Questions (FAQ)

Q1: What is a normal PVR volume?
A: Normal PVR is typically less than 50 mL. Volumes over 100-150 mL may indicate urinary retention.

Q2: How accurate is this calculation compared to catheterization?
A: Ultrasound estimation is about 90% accurate compared to catheterization, with a tendency to slightly underestimate true volume.

Q3: When should PVR be measured?
A: PVR should be measured when evaluating urinary symptoms like frequency, urgency, incontinence, or suspected retention.

Q4: Are there limitations to this calculation?
A: Accuracy decreases with very large or irregularly shaped bladders. Patient position and operator technique can also affect measurements.

Q5: How often should PVR be checked?
A: Frequency depends on clinical context - may range from single assessment to periodic monitoring for chronic conditions.