Bladder Capacity (Ounces) Equals Age (years) Plus 2 Predicts Normal Bladder Capacity and Aids in Diagnosis of Abnormal Voiding Patterns

Abstract

Standardization of the bladder capacities of children will improve the precision of urodynamic evaluation. In an attempt to develop a practical guide to predict the normal bladder capacity during childhood the bladder capacities of 132 children without a clinically abnormal pattern of voiding were measured. When the bladder capacities are correlated by age the following linear relationship exists: normal bladder capacity (ounces) equals age (years) plus 2. The bladder capacities of 68 children with primary enuresis, frequency or infrequent voiding were then measured. Children with clinically infrequent voiding demonstrated large bladder capacities and those with frequency or enuresis demonstrated small bladder capacities compared to normal children. The formula appears to be a useful guide to predict normal bladder capacity by age and also to aid in the diagnosis of abnormal voiding patterns.

Relevance of Constipation to Enuresis, Urinary Tract Infection and Reflux

“…By history, physical examination includ ing rectal examination and rectal manometric studies, constipation was an extremely common though often unrecognized accompaniment of enuresis. These patients had uninhibited bladder contractions similar to that pre viously observed by Berger et al [12] who also noted a decreased bladder capacity in relation to age in many of these patients, a phenomenon similarly noted by us. Aggressive treatment of constipation resulted in rapid resolution of enuresis without any form of pharmocologic drug therapy.…”

Daytime Functional Bladder Capacity as a Predictor of Response to Desmopressin in Monosymptomatic Nocturnal Enuresis

“…Therefore, the graph in figure 1 can be used to predict the changes of successful response of enuretics to DDAVP therapy in relation to their bladder capacity. The maximum functional bladder capacity values as measured by the highest value of spontaneously voided urine, and maximum capacity as measured at cytoscopy showed a linear correlation until age 11 years [4, 7, 8]. …”

Assessing bladder capacity in children: Is it feasible at all?

“…Linear or non-linear relationship between voided volume and others uro£owmetric parameters were described. Bladder capacity was presented as a function of age in children population [Berger et al, 1983;Ko¡, 1983;Fairhurst et al, 1996;Kea¡er et al, 1997]. In fact, one must be aware of what is the expected bladder volume for the patient to make the exact comparison and ¢nally the correct diagnosis.…”