Maximum and average urine flow rates in normal children--the Miskolc nomograms

Area of Science:

• Pediatric Urology
• Clinical Nephrology
• Biomedical Engineering

Background:

• Establishing normative data for physiological parameters is crucial for accurate clinical assessment.
• Urinary flow rate is a key indicator of lower urinary tract function in children.

Purpose of the Study:

• To determine normal reference ranges for maximal and average urinary flow rates in healthy children.
• To develop nomograms for urinary flow rates stratified by body surface area and sex.

Main Methods:

• Analyzed 433 micturitions from 200 healthy children (3-18 years old).
• Categorized children by body surface area (< 0.92 m2, 0.92-1.42 m2, > 1.42 m2).
• Measured voided volume, maximum, and average flow rates, fitting data with mathematical functions.

Main Results:

• A logarithmic function best described the relationship between flow rates and voided volume.
• Presented centile-based nomograms for maximal and average urine flow rates for boys and girls across body surface area groups.
• Observed higher average maximal and average flow rates in girls compared to boys.

Conclusions:

• Normal nomograms for maximal and average urine flow rates in children are provided.
• These nomograms are valuable tools for diagnosing lower urinary tract disturbances in pediatric populations.
• The data support the use of these nomograms across a wide range of body sizes and voided volumes.