Analysis of urinary flow rate in normal infants

Uroflowmetrical studies were undertaken in 126 normal infants, consisting of 70 boys and 56 girls in the city, aging between 1 and 6 years and being divided into two group : Ypunger age group (between 1 and 3 years) and elder age group (between 4 and 6 years). We used urodata system OM-3 which was applied in the nursery school to obtain total 371 urinary flow curves. We examined the following 6 paraments : (1) maximum flow rate (Qmax), (2) expected minimum flow time (voiding volume/maximum flow rate, V.V./Qmax, (3) √<voiding volume>/maximum flow rate (√<V.V.>/Qmax), (4) voiding time (Vtime), (5) time to maximum flow rate (T Qmax) and (6) time to maximum flow rate/voiding time (T Qmax/Vtime). The results obtained were shown as follows : (1) Qmax was higher in elder age group than in younger age group in both boys and girls. The sex difference was larger in girls than in boys in elder age group but no significant was noted in younger age group.(2) V.V./Qmax remained at same level under 100ml without differences among 4 groups with mean values of 6.2±1.3sec. (3) √<V.V.> V.V./Qmax remained constant independent upon the voiding volume. This parameter was higher in younger age group (0.82±0.16) than in elder age group (0.74±0.14) I girls while it was higher in boys (0.80±0.15) than in girals (0.74±0.14). It resulted in overall mean values of (0.79±0.12). (4) Vtime was positively well correlated with the voiding volume on regression linear curves with a steepner slope in boys than in girls and in younger age group than elder age group but without noticeable significant difference, (5) T Qmax was positively well correlated with the voiding volume but no diggerences among 4 group. (6) T Qmax/Vtime remained at same level without influences from the voiding volume, being higher in elder age group (0.40±0.09) than in younger age group (0.34±0.10) in girls and higher in boys (0.40±0.08) than in girls (0.34±0.10) in younger age group.