Is 225 mL of post-void residual urine serious?

Question

Hello doctor,

Unfortunately, I am now suffering from nighttime incontinence and feel my stream is weaker and thinner. I feel pressure in my rectum when urinating. Could you please interpret my urodynamics test? The nurse did have issues getting a catheter in, and I was completely unable to pee when the catheter was in. I feel as if I am not emptying my bladder completely. I have persistent urinary infections and urine retention. I underwent TURP and urethral dilation for the same. I was previously admitted for a complete obstruction.

Here are my test values:

Total voided volume: 724 mL.
Maximum flow rate (Qmax): 25.7 mL/s.
Mean flow rate: 12.8 mL/s.
Voiding time: 56.6 seconds.
Time to maximum flow: 7.8 seconds.
Post-void residual urine (PVR): 225 mL.

Could you please explain what these values mean and whether they suggest any ongoing obstruction or bladder weakness? Also, what would be the next recommended steps in evaluation or management?

Please help.

Thank you.

Answer 1

Hello,

Welcome back to icliniq.com.

I understand your concern.

I saw your test reports (attachments removed to protect the patient's identity). This appears to be a uroflowmetry study rather than a full urodynamic study. I will interpret it step by step for better understanding and then provide my overall impression.

Key Parameters

Total voided volume: 724 mL.
Maximum flow rate (Qmax): 25.7 mL/s.
Mean flow rate: 12.8 mL/s.
Voiding time: 56.6 seconds.
Time to maximum flow: 7.8 seconds.
Post-void residual urine (PVR): 225 mL.

1. Flow Rate (Qmax = 25.7 mL/s) : Normal

A Qmax above 15 mL/s is generally considered normal in adult males, provided there are no significant symptoms. This indicates that the flow strength itself is good. Based on flow rate alone, there is no clear evidence of significant bladder outlet obstruction.

2. Flow pattern: Slightly variable but acceptable.

The graph shows some fluctuations, but the void appears reasonably strong.

There may be intermittent abdominal straining (not certain). If straining is present, a mild urethral stricture could be a possibility, which is relatively common after a TURP procedure.

3. Large voided volume (724 mL): High.

A normal voided volume is approximately 250–400 mL.

A volume of 724 mL suggests:

Increased bladder capacity.
Potential overestimation of Qmax, as larger volumes can generate higher flow rates.

4. High Post-Void Residual (PVR = 225 mL): Abnormal.

This is the most significant finding.

Normal PVR values:

<50 mL - normal.
50–100 mL - borderline.
200 mL - significant urinary retention.

A PVR of 225 mL indicates incomplete bladder emptying.

Possible causes:

Detrusor underactivity.
Bladder outlet obstruction, most likely due to a urethral stricture, which is a known complication after TURP(transurethral resection of the prostate).

I suggest consulting a urologist for urethral calibration. If calibration with 16 to 20 degrees Fahrenheit improves symptoms, regular calibration may be required. If symptoms do not improve after calibration, a full urodynamic study should be performed to document possible detrusor underactivity. However, based on your history of good voiding immediately after the procedure, a urethral stricture appears more likely.

I hope this helps.

Kindly follow up if you have more concerns.

Thank you.