"Bladder Effect" - An Urodynamic Parameter to Distinguish Subtypes of Urinary Incontinence in Women.

Background: Urinary incontinence (UI) is defined by the International Continence Society (ICS) as the involuntary loss of urine that represents a hygienic or social problem to the individual. The aetiology is multifactorial. The diagnosis of UI is important because it can result in the application of appropriate therapy. Urodynamics is a golden standard, without which every UI diagnosis is insufficient.

Aim: The goal of this study was, based on urodynamic results, to prove the existence of evident differences between the subtypes of UI.

Methods: Eighty patients with UI were evaluated (50 with urinary stress incontinence-USI and 30 with detrusor instability-DI) according to a standard evaluation protocol. Exclusion criteria were: mixed UI and diseases that simulated UI. All patients were 36-65 years of age (mean 56). The following parameters were measured: maximal and average flow, maximal and average voiding pressure. These parameters were compared between both groups, to determine the diagnostic significance of the parameter "Bladder Effect" (BE). It is a product of the urine flow and the pressure during voiding.

Results: The results showed a significant difference with a high confidence interval. Mean BEmax was 577 units in the patient group with USI, and 1014 in the DI group. Similarly, BEav was 313 units in the USI group, and 499 units in the DI group, with a significant difference and a high interval of confidence.

Conclusion: In conclusion, the results of the study suggested that BE could be a useful diagnostic parameter to distinguish between USI and DI.