Does the potassium stimulation test predict cystometric, cystoscopic outcome in interstitial cystitis?

PURPOSE

We establish the relationship among symptom duration, cystometric and cystoscopic findings and potassium stimulation test in patients with interstitial cystitis.

MATERIALS AND METHODS

A retrospective chart review was performed of 189 patients treated at an ambulatory clinic between 1992 and 1998. Urodynamic parameters, potassium stimulation test results and subjective response to treatment were evaluated. Fisher's exact test was used for statistical analysis.

RESULTS

Of the 189 patients diagnosed with interstitial cystitis 173 (92%) were female and 16 (8%) were male. The potassium stimulation test was positive in 105 (83%) patients, negative in 16 (13%) and equivocal in 6 (4%). A cystometrogram and potassium stimulation test were done in 118 patients. Bladder capacity averaged 259 ml. in patients with tests potassium positive and negative, while average bladder volume at first sensation to void was 85 ml. and 148 ml. in those with negative and positive tests, respectively. Among the 102 patients with a positive potassium stimulation test 52 had normal cystoscopic findings.

CONCLUSIONS

The potassium stimulation test is not correlated with either bladder capacity or cystoscopic findings.