Post Void Residual Volume Calculator

Post Void Residual Volume Formula:

\[ PVR (mL) = Length (cm) \times Width (cm) \times Height (cm) \times 0.5 \]

Post Void Residual Volume (PVR):

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1. What is Post Void Residual Volume?

Post Void Residual Volume (PVR) is the amount of urine left in the bladder after urination. It's an important measurement in urology to assess bladder function and detect urinary retention.

2. How Does the Calculator Work?

The calculator uses the PVR formula:

\[ PVR (mL) = Length (cm) \times Width (cm) \times Height (cm) \times 0.5 \]

Where:

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

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

3. Importance of PVR Measurement

Details: PVR measurement is crucial for diagnosing urinary retention, monitoring treatment effectiveness, and assessing bladder function in neurological disorders.

4. Using the Calculator

Tips: Enter bladder dimensions in centimeters as measured by ultrasound. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a normal PVR volume?
A: Normally less than 50 mL. 50-100 mL may be borderline, and >100 mL is generally considered abnormal.

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

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

Q4: Are there limitations to this calculation?
A: Accuracy depends on precise ultrasound measurements and assumes a regular bladder shape.

Q5: How often should PVR be checked?
A: Frequency depends on clinical context - may be done once or monitored serially for changes.