Is a post-void residual (PVR) volume of 85 milliliters (ml) considered normal?

From the Guidelines

A post-void residual (PVR) volume of 85 milliliters is generally considered normal. Normal PVR volumes are typically less than 50-100 ml, with most experts using a cutoff of less than 100 ml as the normal range for adults 1. Your measurement of 85 ml falls within this acceptable range, indicating that your bladder is emptying adequately during urination. PVR is an important measurement that helps assess bladder function and can identify potential urinary retention issues. The measurement represents the amount of urine remaining in the bladder after voiding is complete.

Higher residual volumes (consistently above 100 ml) might suggest problems with bladder emptying, which could be caused by bladder outlet obstruction, neurological conditions affecting the bladder, or weakened bladder muscles. According to the 2012 AUA/SUFU guideline, clinicians may perform PVR in patients with LUTS as a safety measure to rule out significant urinary retention both initially and during follow-up 1. If you're concerned about urinary symptoms despite having a normal PVR, it's still worth discussing with your healthcare provider as other urinary parameters may need evaluation.

Some key points to consider:

• PVR measurement may be associated with false positives and negatives that could lead to inappropriate treatment 1.
• The potential benefits of measuring PVR include identifying patients with significant urinary retention and thus decreasing potential morbidity 1.
• The risks/harms of assessing PVR using catheterization are low and include urinary tract infection and urethral trauma, which can be eliminated with ultrasound determination of PVR 1.

From the Research

Post-Void Residual Volume

• A post-void residual (PVR) volume of 85 milliliters (ml) may not be considered normal for all individuals, as the definition of a normal PVR volume can vary depending on the context and the individual's overall health 2, 3.
• Studies have shown that a PVR volume of less than 150 ml does not necessarily rule out voiding dysfunction in women 2.
• In fact, one study found that patients with voiding dysfunction often have normal PVR volumes, and that PVR volumes less than 150 ml cannot exclude voiding dysfunction 2.
• Another study suggested that large PVR volumes (>200-300 ml) may indicate marked bladder dysfunction, but that there is no universally accepted definition of a significant residual urine volume 3.

Factors Influencing PVR Volume

• The volume of the bladder prior to voiding (BVvoid) can influence PVR volume, with higher BVvoid volumes resulting in higher PVR volumes 4.
• Bladder voiding efficiency (BVE) is a more reliable parameter than PVR volume for assessing emptying function, as it is less variable and more consistent across repeated measurements 4.
• Age and gender can also influence PVR volume, with children and older adults potentially having different normal ranges for PVR volume 5, 6.

Clinical Implications

• PVR volume should be considered in the context of other clinical parameters, such as symptoms, medical history, and physical examination findings, to determine the presence and severity of voiding dysfunction 2, 3.
• Treatment for voiding dysfunction should be individualized and may involve a combination of behavioral modifications, medications, and other interventions, depending on the underlying cause and severity of the condition 5, 6.