How reliable are bladder perceptions during cystometry?

Aims Sensory input is important for bladder control in daily life. It has been reported that perceptions during cystometry are subjective. To help refine this subjectivity, objective and semi‐objective tests (e.g., sensory thresholds of electrical stimulation) have been recommended by The International Continence Society. However, the reliability of such studies has not been established. This study was designed to evaluate the reliability of bladder perceptions during cystometry. Methods The study included 59 patients with urologic complaints. The average age of 40 male and 19 female patients was 58.1 years (range: 14–83). After insertion of an 8F double lumen catheter, patients were blinded to the pump and screen process. During Phase I nothing was infused. In Phase II, filling cystometry was performed with 50 ml/min pump speed and then the bladder was emptied. Phase III was performed with the same method used in Phase I. The time that each sensation was perceived, in seconds, was used to compare sensations. The bladder volume, at which sensations were perceived, was recorded at Phase II. Results Except for strong desire, there were no statistically significant differences between the mean times in seconds elapsed till sensations in Phases I and III, but they were different from those in Phase II. The time elapsed until strong desire was not different in each of the three phases. However, there was strong a correlation in the ratios of sensations to strong desire between Phase I and II (r = 1, P = 0.01), Phase I and III (r = 0.99, P = 0.01), and Phase II and III (r = 0.98, P = 0.01). Conclusions Proprioception of the bladder filling during cystometry is subjective. This data shows that sensations noticed by the patient during filling cystometry may be related to stimuli other than bladder filling. © 2004 Wiley‐Liss, Inc.