From the Guidelines
Abnormal post-void urine volume is generally considered to be greater than 100 mL of urine remaining in the bladder after urination. When evaluating post-void residual urine (PVR) volume, it's essential to consider the clinical context and potential underlying causes of abnormal volumes. According to the AUA guideline on management of benign prostatic hyperplasia 1, large PVR volumes (e.g., 350 ml) may indicate bladder dysfunction and predict a slightly less favorable response to treatment. However, the guideline also notes that residual urine is not a contraindication to watchful waiting or medical therapy, and no level of residual urine, in and of itself, mandates invasive therapy 1. Key points to consider when evaluating PVR volume include:
- A normal PVR is typically less than 50 mL, with volumes between 50-100 mL falling into a gray zone that may require clinical correlation
- Elevated PVR volumes indicate incomplete bladder emptying, which may result from various causes such as bladder outlet obstruction, detrusor underactivity, neurogenic bladder dysfunction, or certain medications
- Persistently elevated PVR volumes can lead to complications including urinary tract infections, bladder stones, and upper urinary tract damage
- Management depends on the underlying cause but may include addressing any obstruction, adjusting medications that affect bladder function, implementing timed voiding schedules, or in some cases, teaching clean intermittent catheterization if the volume consistently exceeds 300 mL or causes symptoms. It's crucial to prioritize the patient's overall health and quality of life when making decisions regarding PVR volume management, taking into account the potential risks and benefits of different treatment approaches 1.
From the Research
Abnormal Post Void Urine Volume
Abnormal post void urine volume refers to the amount of urine that remains in the bladder after urination. The normal volume of post void urine is typically considered to be less than 50 mL 2.
Factors Influencing Abnormal Post Void Urine Volume
Several factors can influence abnormal post void urine volume, including:
- Age: Older adults are more likely to have higher post void urine volumes 2
- Voiding dysfunction: Patients with voiding dysfunction may have higher post void urine volumes 3
- Urinary symptoms: Women with post void urine volumes of 100 mL or greater are more likely to report urinating more than eight times during the day and weekly urgency incontinence 2
Measurement of Post Void Urine Volume
Post void urine volume can be measured using various methods, including:
- Bladder ultrasonography: This method uses ultrasound waves to measure the volume of urine in the bladder 3, 2
- Urethral catheterization: This method involves inserting a catheter into the bladder to measure the volume of urine 3
Clinical Significance of Abnormal Post Void Urine Volume
Abnormal post void urine volume can be associated with various clinical significance, including: