Normal Post-Void Residual Urine Volume
The normal post-void residual (PVR) urine volume is generally considered to be less than 50-100 mL in adults, with values above this threshold potentially warranting further evaluation. While there is no universally accepted definition of a significant residual urine volume, understanding normal ranges is essential for clinical decision-making.
Normal PVR Values by Population
Adults
- Men:
- 90th percentile: 73.2 mL (25% of bladder volume)
- 95th percentile: 102.6 mL (30% of bladder volume) 1
- Women:
- 90th percentile: 60.5 mL (21% of bladder volume)
- 95th percentile: 93.8 mL (27% of bladder volume) 1
Adolescents
- Males 12-14 years:
- 90th percentile: 20 mL (7% of bladder volume)
- 95th percentile: 30 mL (8% of bladder volume) 2
- Males 15-18 years:
- 90th percentile: 20 mL (7% of bladder volume)
- 95th percentile: 30 mL (11% of bladder volume) 2
- Females 12-14 years:
- 90th percentile: 25 mL (9% of bladder volume)
- 95th percentile: 35 mL (11% of bladder volume) 2
- Females 15-18 years:
- 90th percentile: 35 mL (10% of bladder volume)
- 95th percentile: 45 mL (13% of bladder volume) 2
Clinical Significance of PVR
Risk Thresholds
- 180 mL: Some studies have suggested this as a threshold where risk of bacteriuria significantly increases in men, with a positive predictive value of 87.0% 3. However, subsequent research has questioned the validity of this specific cutoff 4.
- 100-200 mL: Values in this range may warrant monitoring but are not necessarily pathological 5, 6.
- >200-300 mL: Large PVR volumes in this range may indicate marked bladder dysfunction and could predict less favorable responses to treatment 5, 6.
PVR Measurement Recommendations
- Timing: The interval between voiding and PVR measurement should be short to ensure accuracy 6.
- Method: Ultrasound bladder volume measurement is preferred to urethral catheterization 6.
- Repeatability: Due to marked intra-individual variability, PVR should be repeated to improve precision, particularly if the first measurement is significant 5.
When to Measure PVR
PVR measurement is recommended in:
- Initial diagnostic assessment of patients with lower urinary tract symptoms (LUTS) 5
- Monitoring response to treatment 5
- Prior to intradetrusor botulinum toxin therapy for overactive bladder 5
- Following botulinum toxin injection if symptoms have not improved or worsened 5
- Patients with intermittent catheterization (recommended if PVR >100 mL) 5
Clinical Implications
- PVR does not strongly predict acute urinary retention 6
- PVR does not specifically indicate the presence of bladder outlet obstruction 6
- PVR increases with bladder volume and may significantly increase when bladder volume reaches around 528 mL 1
- Women generally have lower PVR than men 1
- PVR increases as International Prostate Symptom Score (IPSS) increases 1
Practical Approach to Interpreting PVR
- <50 mL: Generally considered normal
- 50-100 mL: Likely normal but may warrant monitoring in certain clinical contexts
- 100-200 mL: May indicate dysfunction; consider repeating measurement and clinical correlation
- >200 mL: Suggests significant bladder dysfunction; may affect treatment decisions, particularly for invasive therapies
Remember that PVR should be interpreted in the context of the patient's symptoms, other diagnostic findings, and clinical presentation rather than as an isolated value.