Postvoid Residual Volume of 15 mL: Normal or Abnormal?
A postvoid residual (PVR) bladder volume of 15 mL is normal and not clinically concerning. This value falls well within the normal range for healthy individuals and does not require further evaluation or intervention.
Normal PVR Values
- A median PVR volume of 19 mL (range 0-145 mL) with a mean of 24±29 mL has been established in asymptomatic perimenopausal and postmenopausal women 1
- Most asymptomatic individuals (95%) have a PVR volume of 100 mL or less 1
- Only 15% of asymptomatic individuals have a PVR volume greater than 50 mL 1
Clinical Significance of PVR Measurements
- Intermittent catheterization is recommended only if postvoid residual urine volume is >100 mL 2
- A PVR of 15 mL indicates effective bladder emptying and is not associated with urinary retention 2
- PVR measurement has a 63% positive predictive value for bladder outlet obstruction recognition at the 50 mL threshold 2
Factors That Can Affect PVR Measurements
- Premicturitional bladder volume significantly impacts PVR measurements - an uncomfortably full bladder (>540 mL) before voiding can result in falsely elevated PVR values 3
- Age ≥65 years may be associated with higher mean PVR volumes, but hormone therapy, vaginal atrophy, parity, and asymptomatic prolapse do not significantly affect PVR volumes 1
- PVR should be measured within 10 minutes of voiding for accurate results 1
Measurement Techniques
- Transabdominal ultrasonography is a reliable, non-invasive method for assessing PVR 4
- For accurate measurements, the bladder should be imaged in both transverse and sagittal planes 5
- Patient self-measurement of PVR using portable ultrasound devices is feasible and reliable, showing high correlation with provider measurements 6
When to Be Concerned About PVR
- PVR values >50 mL may warrant clinical attention in some contexts 3
- PVR values >100 mL may indicate incomplete bladder emptying requiring further evaluation 2
- Persistently elevated PVR volumes increase the risk of urinary tract infections and may indicate underlying urological or neurological issues 2
Pitfalls in PVR Measurement
- An overly distended bladder before voiding can cause artificially elevated PVR measurements 3
- Measurement should be performed within 10 minutes after voiding to avoid refilling of the bladder 1
- Failure to specify post-void imaging may result in incomplete assessment of bladder function 5
In conclusion, a PVR of 15 mL is well within normal limits and indicates effective bladder emptying. This value would not be considered abnormal in clinical practice and does not require further evaluation or intervention.