Age- and gender-specific nomograms for single and dual post-void residual urine in healthy children

Area of Science:

• Pediatric Urology
• Diagnostic Imaging
• Urodynamics

Background:

• Accurate interpretation of post-void residual urine (PVR) is crucial for diagnosing pediatric lower urinary tract dysfunction.
• Existing PVR reference values lack age and gender specificity, potentially leading to misdiagnosis in children.
• Development of age- and gender-specific nomograms is needed to improve diagnostic accuracy.

Purpose of the Study:

• To establish the first age- and gender-specific nomograms for single and two consecutive post-void residual urine (PVR) tests in healthy children.
• To provide reference standards for interpreting PVR measurements in pediatric populations.
• To aid in the early and accurate diagnosis of lower urinary tract dysfunction in children.

Main Methods:

• Enrollment of healthy children aged 4-12 years for uroflowmetry and PVR testing.
• Inclusion of the first PVR and the lower value of two consecutive PVRs (voided volume ≥50 ml) for nomogram construction.
• Exclusion of children with suspected urinary tract infections or lower urinary tract dysfunctions.

Main Results:

• Nomograms were constructed for single and dual PVR measurements in 1,128 children (583 boys, 545 girls).
• The 95th percentile for single PVR was 27.2 ml (19.2% of bladder capacity), and for dual PVR was 11.2 ml (6.0% of bladder capacity).
• PVR was associated with bladder capacity, age, gender, and uroflow patterns, with redefined elevated thresholds for different age groups.

Conclusions:

• Age, gender, and bladder capacity are essential factors in interpreting pediatric PVR tests.
• Repeating a PVR test is recommended if a single measurement exceeds the 95th percentile of age- and gender-specific nomograms.
• These new nomograms enhance the diagnostic utility of PVR testing in pediatric urology.