Bladder diaries, urge scales, bladder questionnaires, and focus groups have all been utilized to better understand bladder sensation. However, aside from ICS-defined verbal sensory thresholds, there is currently no standardized method of characterizing changes in bladder sensation during filling. The purpose of this investigation was to utilize an updated model of a previously developed sensation meter to more objectively characterize real-time bladder sensation events during oral hydration in healthy volunteers [1].

Investigators executed an accelerated hydration protocol where participants drank 2L Gatorade-G2® and used the sensation meter device to record real-time bladder sensation (0-100%), verbal sensory thresholds, and novel sensation descriptors of “tense,” “pressure,” “tingling,” “painful,” and “other” for two consecutive fill-void cycles.

21 participants (12 female/9 male) completed the protocol. Data demonstrated an average of 8-9 sensation events per fill with no differences in the total number of sensation events and volume between sensation events (fill 1 vs. fill 2). An increased number of sensation events occurred at higher sensation quartiles, with the majority of bladder sensation events, regardless of fill rate or end volume, being perceived at >50% sensation (Fig.1a,b). Event descriptors of “pressure” and “tingling” were the most commonly chosen descriptors in both fills (Fig.2).

On average, participants recorded 8-9 sensation events in both fills, suggesting that previously recognized VSTs might be inadequate to characterize the full range of bladder sensation. Histograms of sensation events (Fig.1c) demonstrated that an exponential and linear function better fit fill 1 and fill 2, respectively. This is most likely from an increase in bladder diuresis during fill 1 in comparison to a more constant fill rate in fill 2. These observations support our variable fill rate protocol and are consistent with previous ultrasound study results [1]. Pressure and tingling were marked throughout both fills, whereas tense and painful were generally felt at sensations >40% and >75%, respectively (Fig.2). While descriptor combinations such as tingling alone vs. tense-tingling were explored, no one pattern was dominant, further highlighting the multidimensional complexity of understanding bladder sensation.

This study demonstrates increased events per fill compared to ICS standards, acceleration of sensation during filling, and unique sensation event descriptor patterns. Sensation event descriptors of tense, tingling, pressure, and painful enable a more comprehensive understanding of bladder sensation as well as real-time identification, quantification, and characterization of sensation events. Applicable to variable fill rate protocols, the sensation meter may be implemented in various settings for the purpose of identifying novel sensation patterns associated with OAB and aging.

Nagle AS, Speich JE, De Wachter SG, et al: Non-invasive characterization of real-time bladder sensation using accelerated hydration and a novel sensation meter: An initial experience. Neurourol Urodyn. 2017;36:1417-1426.