Routine uroflowmetry and post-void residual urine in primary nocturnal enuresis

Purpose: To examine the results of routine uroflowmetry and postvoid residual urine (PVR) in children with primary nocturnal enuresis (PNE).

Materials and Methods: Children with PNE underwent two sets of uroflowmetry and PVR by transabdominal ultrasound. Uroflowmetry pattern were reported as ICCS classification. Elevated PVR is defined as >20 ml in children aged 4–6 years, and >10 ml in children aged 7–12 years, respectively.

Results: Totally, 82 children with a mean age of aa ± bb years were enrolled for study. Boy to girl ratio was cc: dd. Of the first 82 uroflowmetry curves 52 (63.4%) and 30 (36.6%) were bell and non-bell shaped, respectively. Of the 30 non-bell shaped curves 6 (25.0%) were normal at repeat uroflowmetry test. Finally, repeat staccato curves were observed in 12 chidren, tower in 8, plateau in 2, intermittent in 1, and obstructive in 1.

Mean value of first PVR was aa ± bb ml. First PVR was elevated in 27 (32.9%) children of whom second PVR was normal in 21 (77.8%) children. Of the 6 children with repeated elevated PVR 4 had bell-shaped uroflowmetry curves and 2 had non-bell shaped curves. Finally, Repeat abnormal uroflowmetry curves and/or repeat elevated PVR were noted in 27 (32.9%) children. Repeat uroflowmetry and PVR tests may avoid 25% and 77.8% unnecessary invasive urodynamic tests, respectively.

Conclusion: Routine uroflowmetry and postvoid residual urine examinations are recommended in children with primary nocturnal enuresis because potential lower urinary tract dysfunction was observed in one third of children with PNE. Repeat uroflowmetry and PVR tests are recommended to avoid unnecessary invasive urodynamic tests.