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.

OBJECTIVE

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).

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.

CONCLUSIONS

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.