Four-hour voiding observation: Normative data from term Indian neonates

Abstract

BackgroundThe four-hour voiding observation is an important non-invasive urodynamic test for infants and young children before toilet training. The study was performed to generate normative data for term Indian neonates. MethodsThe study was a descriptive study performed in the Department of Paediatrics of a secondary care hospital in South India with patients having nationwide representation from August 2018 to August 2020. Term neonates, appropriate for gestational age on days 4–14 of life were included. Neonates at risk of oliguria or abnormal bladder functions were excluded. Four-hour voiding observation was performed by direct observation of voids, pre- and post-void diaper weight and measurement of post-void residue (PVR) by ultrasonography using two formulae within five minutes of voiding. ResultsA total of 102 neonates (166 voids) were studied. Important results were (a) Eight neonates did not void; (b) median (fifth–95th percentile) of important test outcomes as follows: voided volume: 15 (7.5–33.5) ml, maximum voided volume (MVV) 16.5 (8.0–38.7) ml, PVR 3.2 (0.5–10.2) ml, PVR% 17.0 (2.9–46.4) % functional bladder capacity 19.7 (9.6–38.0) ml, and diuresis: 1.7 (0.0–5.1) ml/kg/hour; (c) four (4.3%) neonates had one interrupted void each; (d) linear regression yielded the following formulae: MVV (ml) = 8.1019 + 4.8702 ∗Diuresis (ml/kg/hr) and PVR % (max) = 14.2312 + 3.2682∗ Diuresis (ml/kg/hr). ConclusionNormative data on the four-hour voiding observation study for Indian term exclusively breast-fed neonates are reported.