Four-hour voiding observation in healthy infants.

Abstract

We present the 4-hour voiding observation as a method for basic assessment of bladder function in infants and nontoilet trained children. Voiding pattern, including number of voidings, voided volume, bladder capacity and residual urine for 4 hours, was determined noninvasively in 43 healthy infants. The infants voided an average of 1 time per hour but with great variability. Bladder capacity increased with age according to the formula, 38 + 2.5 x age (months). Mean residual urine plus or minus standard deviation was 4.6 +/- 3.0 ml. In all infants residual volume was less than 5 ml. at least once during observation. The 4-hour voiding observation is an easy noninvasive method of characterizing the voiding pattern, focusing especially on emptying difficulties, in infants and nontoilet trained children.