Urinary flow studies in normal kindergarten--and schoolchildren.

The problems in the evaluation of children with suspected infravesical obstruction are shortly reviewed. Based upon literature studies it is concluded, that an isolated urinary flow measurement determining the Qmax is a suitable procedure of screening. Due to different shortcomings of earlier published normal materials, we investigated the spontaneous urination of 205 normal children aged 3 to 13 years in their normal environment. The mictiograph was installed in the toilet of two kindergartens and one school, enabling the children freely to void into the machine upon desire. From the flow curves the following parameters were calculated: Q1 sec, Qmax, Qmax time, and the micturition time, all of them being related to the square root of the voided volume. The data were non-parametrically statistically processed, and the limits of normal values (2 1/2% and 97 1/2% percentiles) are defined for different groups of age and sex. Furthermore, the different flow curve patterns are described, and it is found, that in 90% of the cases they are identical to the adult pattern.