Male Peak Urinary Flow Rate: Relationships to Volume Voided and Age

Abstract

Studies [126] of replicate voiding in 7 individuals and 552 observations in normal, abnormal or treated male populations were performed with a disposable device that measures peak flow and volume voided. A voided volume of 150 ml may be used as the minimum acceptable volume for studies of male subjects in which peak flow is used to define normal vs. abnormal voiding. At volumes greater than 150 ml a straight line describes the relationship between volume voided and peak flow as accurately as the previously suggested hyperbolic curve. Increasing age of men again reveals progressive decrease in peak flow rate no matter what volume is voided. Comparison of peak flow rate, volume voided and age by 3-dimensional graphing was attempted but was found unsuccessful for clinical use. Three biaxial linear graphs may be used to chart effectively the 3 parameters (age, volume and peak flow) and thereby judge normality or abnormality of peak flow rate for any age and volume voided.