Positive response to ice water test associated with high-grade bladder outlet obstruction in patients with benign prostatic hyperplasia.

摘要

OBJECTIVES: To elucidate the clinical significance of detrusor overactivity (DO) that is probably due to C-fiber activation caused by bladder outlet obstruction (BOO), we examined the responses to the ice water test (IWT) in patients with benign prostatic hyperplasia (BPH) and assessed the results with reference to the clinical manifestations and urodynamic findings. METHODS: A total of 127 patients without neurologic disease, who were older than 50 years of age, with an International Prostate Symptom Score of 8 points or greater and a quality of life index of 2 or more points, were enrolled in this study. We tested the response to ice water instillation by monitoring the intravesical pressure in all cases and assessed the results with reference to the findings of International Prostate Symptom Score and quality of life index questionnaires, BOO indexes, 48-hour frequency volume charts, prostate volume, and data from free-flowmetry and pressure flow studies for detecting DO. Twenty patients with neurogenic bladder dysfunction underwent IWT as a control group. RESULTS: The responders to the IWT accounted for 14 (70%) of the 20 patients with neurogenic bladder dysfunction and 35 (27%) of the 127 patients without neurologic disease. All of these responders showed DO on the pressure flow studies. The patients without neurologic disease who responded to the IWT had higher BOO indexes than did the nonresponders and had a smaller volume at a maximal desire to void on the urodynamic studies. The largest single-voided volume recorded from the 48-hour frequency volume charts was also smaller for the responders than for the nonresponders. CONCLUSIONS: The patients with BPH clearly showed that DO was mainly due to active C-fibers stimulated by high-grade BOO and that DO was a cause of urgency and frequency-related symptoms with decreased bladder capacity. It will be necessary to assess the inhibitory effect of capsaicin on DO caused by activation of C-fibers and the reversibility of C-fiber activation after surgical treatment for BPH, so that the criteria for decision-making for the treatment of BPH may be clarified with the aid of the IWT.