From the Guidelines
The normal residual volume in a post-void bladder is typically less than 100 milliliters (ml) in adults. After urination, it's expected that the bladder will empty almost completely, with only a small amount of urine remaining. Post-void residual (PVR) volumes exceeding 100 ml may indicate incomplete bladder emptying, which could be caused by various conditions such as urinary obstruction, neurogenic bladder dysfunction, or detrusor muscle weakness 1. PVR can be measured using either ultrasound, which is non-invasive and commonly used in clinical settings, or catheterization, which is more invasive but provides a direct measurement.
Key Points to Consider
- Regular monitoring of post-void residual volume is important for patients with urinary symptoms, neurological conditions affecting bladder function, or those recovering from urological procedures.
- The bladder's ability to empty effectively relies on coordinated function between the detrusor muscle (which contracts during urination) and the urethral sphincter (which relaxes to allow urine flow), along with adequate bladder pressure to overcome any resistance in the urinary tract.
- Large PVR volumes may indicate bladder dysfunction and predict a slightly less favorable response to treatment, however, residual urine is not a contraindication to watchful waiting or medical therapy 1.
Clinical Implications
- Intermittent catheterization is recommended if postvoid residual urine volume is >100 mL 1.
- Voiding strategies should be incorporated into the daily plan of care to decrease the number of incontinent episodes and prevent complications such as dermatitis, skin breakdown, UTIs, and perineal thrush 1.
From the Research
Normal Residual Volume Post Void Bladder
- The normal residual volume post void bladder is not universally defined, but studies suggest that a large post-void residual (PVR) volume (>200-300 ml) may indicate marked bladder dysfunction 2.
- In healthy adolescents, the age- and gender-specific normal PVR urine volume is recommended to be used, with values ranging from 20-45 ml (7-13% of bladder volume) depending on age and gender 3.
- In women, PVR volume and PVR percentage correlate with bladder outlet obstruction (BOO) but not with detrusor contraction strength parameters 4.
- In men with lower urinary tract symptoms, the post-void residual urine ratio (PVR-R) is a predictor of BOO, and a clinical nomogram has been developed to predict BOO based on PVR-R, bladder wall thickness, and prostate volume 5.
- The diagnosis of bladder outlet obstruction in women can be made using video urodynamic criteria, which include radiographic evidence of obstruction between the bladder neck and distal urethra in the presence of a sustained detrusor contraction 6.
- The following values are considered abnormal: