Current concepts and controversies in urodynamics

The influence of water intake on waiting time prior to uroflowmetry: a prospective, randomized, double-blind trial

Background: In uroflowmetry examination, patients are usually instructed to intake a large volume of water and wait until the bladder is full. The association between the volume of water intake and the waiting time before uroflowmetry is unknown. The aim of this study is to investigate the relationship between the volume of water intake and the waiting time prior to uroflowmetry.Methods: This trial was designed as a randomized, researchers, caregivers and patients blinded, superiority trial with three parallel groups and primary endpoint of waiting time prior to the uroflowmetry study based on the volume of patients’ water intake. Randomization was performed by block randomization with a 1:1:1 allocation. Patients scheduled for uroflowmetry at the Urology Clinic of Cipto Mangunkusumo Hospital were enrolled from March 2013 until December 2013. The eligibility criteria were male patients with ages above 50 years and body mass index 18.5–24.9 kg/m2.Results: A total of 83 patients was randomly assigned into 3 study groups: 300 ml (28 patients), 400 ml (28 patients), and 500 ml (27 patients). All patients were included in final analysis. Mean waiting time were 85.1±59.8 min, 107.2±70.4 min, and 66±28.4 min for patients intake 300, 400, and 500 ml of water respectively (p=0.07). The final bladder volumes for three groups were statistically different (262.4±130.8 ml, 289.4±126.2 ml, 359.2±137 ml; p=0.02).Conclusion: The volume water intake of 300–500 ml did not affect waiting time before uroflowmetry. Increasing water intake at least 500 ml added the final bladder volume and shorter the waiting time.

A noninvasive bladder sensory test supports a role for dysmenorrhea increasing bladder noxious mechanosensitivity

OBJECTIVE

Catheterization to measure bladder sensitivity is aversive and hinders human participation in visceral sensory research. Therefore, we sought to characterize the reliability of sonographically estimated female bladder sensory thresholds. To demonstrate this technique's usefulness, we examined the effects of self-reported dysmenorrhea on bladder pain thresholds.

METHODS

Bladder sensory threshold volumes were determined during provoked natural diuresis in 49 healthy women (mean age, 24±8 y) using 3-dimensional ultrasound. Cystometric thresholds (Vfs, first sensation; Vfu, first urge; Vmt, maximum tolerance) were quantified and related to bladder urgency and pain. We estimated the reliability (1-wk retest and interrater). Self-reported menstrual pain was examined in relationship to bladder pain, urgency, and volume thresholds.

RESULTS

Average bladder sensory thresholds (mL) were Vfs (160±100), Vfu (310±130), and Vmt (500±180). Interrater reliability ranged from 0.97 to 0.99. One-week retest reliability was Vmt=0.76 (95% CI, 0.64-0.88), Vfs=0.62 (95% CI, 0.44-0.80), and Vfu=0.63 (95% CI, 0.47-0.80). Bladder filling rate correlated with all thresholds (r=0.53 to 0.64, P<0.0001). Women with moderate to severe dysmenorrhea pain had increased bladder pain and urgency at Vfs and increased pain at Vfu (P's<0.05). In contrast, dysmenorrhea pain was unrelated to bladder capacity.

DISCUSSION

Sonographic estimates of bladder sensory thresholds were reproducible and reliable. In these healthy volunteers, dysmenorrhea was associated with increased bladder pain and urgency during filling but unrelated to capacity. Plausibly, women with dysmenorrhea may exhibit enhanced visceral mechanosensitivity, increasing their risk to develop chronic bladder pain syndromes.

Quantification of neurological and other contributors to continence in female rats

Smooth muscle, striated muscle, their central and peripheral innervations and control, and mucosal coaptation contribute to maintenance of continence. We used manual leak point pressure (mLPP) testing and electrical stimulation LPP (eLPP) testing in female rats to quantify the contribution of these factors to urethral resistance, a measure of continence. Abdominal muscles were electrically stimulated to induce leakage for eLPP. A Crede maneuver was applied for mLPP. These were repeated after complete T8 spinal cord injury (SCI) and/or bilateral pudendal nerve transection (PNT). After euthanasia, mLPP was repeated. MLPP was not significantly affected by opening the abdomen, suggesting that intra-abdominal pressure transmission contributes little to continence during slow pressure changes. ELPP was significantly higher than mLPP in intact rats, after PNT, and after SCI+PNT, suggesting that abdominal pressure transmission contributes to continence during rapid increases in intra-abdominal pressure. MLPP decreased significantly after PNT, indicating that urethral striated muscles contribute significantly to continence. ELPP decreased significantly after PNT with and without SCI, suggesting that supraspinal control significantly affects continence during rapid pressure changes, but not during slow pressure changes. MLPP after euthanasia was significantly decreased compared to mLPP after SCI+PNT, suggesting that urethral mucosal seal coaptation and tissue elasticity also contribute to continence. The urethra is a complex organ that maintains continence via a highly organized and hierarchical system involving both the central and peripheral nervous systems.