Hyperbaric oxygen for the treatment of interstitial cystitis: long-term results of a prospective pilot study.

OBJECTIVE We conducted a prospective pilot study to assess the safety and efficacy of hyperbaric oxygen (HBO) for the treatment of interstitial cystitis (IC). METHODS Six patients underwent 30 sessions of 100% oxygen inhalation in a hyperbaric chamber and were followed up over 15 months. The measures of efficacy were changes in pain and urgency (visual analog scales), alteration in the patient's assessment of overall change in his well-being (Patient Global Assessment Form), and changes in frequency and functional bladder capacity (48-hours voiding log). Evaluation of symptom severity regarding pain and voiding problems was done using the O'Leary-Sant index. RESULTS Four patients rated the therapeutic result as either excellent or good and assessed their well-being after HBO treatment as improved. Two patients showed only short-term amelioration of some of their symptoms. At 12 months follow-up the baseline functional bladder capacity increased from 37-161 ml (range) to 160-200 ml in the responder group. The 24-hour voiding frequency decreased from 15-27 to 6-11 voids per day, a pain scale improvement from 20-97 mm at baseline to 3-30 mm at 12 months follow-up and an urgency scale improvement from 53-92 mm to 3-40 mm, respectively was observed at 12 month follow-up. The symptom and pain index score decreased from 23-35 at baseline to 3-17 at 12 months follow-up. CONCLUSION HBO appears to be effective to treat IC patients. Treatment was well tolerated and resulted in a sustained decrease of pelvic pain and urgency, improvement of voiding patterns and increase of functional bladder capacity for at least 12 months.