1. What is Post-Void Residual (PVR)?

Post-Void Residual (PVR) is the volume of urine remaining in the bladder after urination. It's an important measurement in assessing urinary retention and bladder function.

2. How Does the Calculator Work?

The calculator uses the PVR formula:

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 formula estimates bladder volume by approximating the bladder as an ellipsoid shape and applying a correction factor.

3. Importance of PVR Measurement

Details: PVR measurement is crucial for diagnosing urinary retention, monitoring bladder function, and evaluating treatment effectiveness for conditions like benign prostatic hyperplasia (BPH) or neurogenic bladder.

4. Using the Calculator

Tips: Enter bladder dimensions in centimeters as measured by ultrasound. All values must be valid (greater than 0). The calculation assumes standard bladder shape.

5. Frequently Asked Questions (FAQ)

Q1: What is a normal PVR volume?
A: Normal PVR is typically less than 50 mL. Volumes over 200 mL generally indicate significant retention.

Q2: How is PVR clinically measured?
A: PVR can be measured by bladder ultrasound or catheterization after voiding.

Q3: When should PVR be checked?
A: PVR should be assessed in patients with urinary symptoms, after urinary retention episodes, or when monitoring bladder function.

Q4: Are there limitations to this calculation?
A: The formula may be less accurate with irregular bladder shapes or when measurements are not taken at maximal bladder dimensions.

Q5: What factors can affect PVR?
A: PVR can vary with hydration status, medications, neurological conditions, and prostate size in men.