Body surface related flow rate nomograms in a normal pediatric population.

Uroflow studies for 511 normal pediatric subjects (272 boys, 239 girls) were analyzed statistically. Nomograms relating peak flow to volume voided and body surface were established. An acceptable lower limit for peak flow was obtained from the data and a volume voided range was calculated so that both criteria could be used with 90% probability to define the normal voiding situation. Body surface area was found to be a more reliable index than age in the establishment of nomograms. In the male population the 90% probability applied to a significantly greater volume voided reliability. In the female population mean peak flow rate rose with increased body surface. Finally, in both sexes the 10% lower limit was closer to the regression mean, allowing a tighter distribution around this value.