Influence of intravesical potassium on pelvic floor activity in women with recurrent urinary tract infections: comparative urodynamics might lead to enhanced detection of dysfunctional voiding.

Objectives: To investigate the influence of intravesical potassium on pelvic floor activity (PFA) during voiding in women with recurrent urinary tract infections (rUTIs) by using comparative urodynamics (CUD).

Patients And Methods: CUD was conducted in 49 women (mean age 34.6 years, range 15-82) with rUTI. Every patient had two sessions of pressure-flow studies with simultaneous measurement of PFA by perineal surface electromyography (EMG); the first was with 0.9% saline and in the second the bladder was filled with 0.2 m KCl solution. All patients had voiding cysto-urethrography, and dysfunctional voiding (DV) was diagnosed when significant PFA was measured by EMG during voiding.

Results: Overall, DV was diagnosed in 37 patients (76%) using CUD; 16 (32%) had DV with saline on the pelvic floor EMG. In all these patients there were significantly greater EMG signals in the presence of KCL. In 21 patients (43%) DV was only detected using KCL; this improvement in the detection rate of DV was statistically significant (P = 0.006). Filling with KCl also prompted a statistically significant difference (P < 0.05) in maximum bladder capacity, maximum and average flow rates and in postvoid residual urine volume.

Conclusion: The present data show that DV is present in most women with rUTI but cannot sufficiently be diagnosed by conventional urodynamics with standard 0.9% saline. The present study suggests that CUD might enhance the detection rates of DV.