Measurement of bladder compliance can be standardized by a dimensionless number: clinical perspective (original) (raw)
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Annals of Translational Medicine
Background: This study aims to validate a recently introduced non-invasive method, ultrasound bladder vibrometry (UBV), for the assessment of detrusor compliance in patients with neurogenic bladders. Methods: The study was carried out on 79 adult patients with neurogenic bladders (60 male and 19 female). The UBV test was performed on each patient to measure the Lamb wave group velocity (c g) in the anterior bladder wall at every 50mL volume increment throughout the filling phase. Bladder compliance was assessed based on the trend of Lamb wave group velocity squared (c g 2) versus volume. A compliance index was defined to differentiate between the compliant and non-compliant bladders. Results of the UBV compliance assessment were validated using the readings of the corresponding urodynamic studies as the clinical gold standard. Results: The Patients' bladders were divided into non-compliant and compliant groups by an experienced urologist using the information in the urodynamic study (UDS) recordings. The compliance index defined on the basis of c g 2 showed a significant difference (P<0.008) between the compliant and non-compliant groups. The areas under the receiver operating characteristic curve were 0.813, with 95% CI ranging from 0.709 to 0.892. Under the optimal criterion, the bladder was considered as non-compliant if the compliance index was less than 100 mL•s 2 /m 2 , resulting in a sensitivity and specificity of 86.4% and 71.9%, respectively. Conclusions: The results of this study demonstrate that UBV can be used as a non-invasive method for the determination of bladder compliance; thus, it can potentially serve as an alternative method to UDS for the appropriate patient groups.
International Urology and Nephrology
Objectives To investigate factors associated with low-compliance bladders (LCB) in pretransplant patients with end-stage renal disease (ESRD) and develop a clinical prediction model for urodynamic studies. Methods This study was a prospective cohort study. Patients with ESRD on the renal transplantation waiting list were recruited and underwent the urodynamic study. Demographics data, predictor factors related to the bladder compliance such as underlying disease of the lower urinary tract disease (LUTD), duration of urine < 250 mL/day, type and duration of renal replacement therapy (RRT), urine volume per day and urodynamic study information were collected. Univariable and multivariable logistic regression models were used to assess the independence of explanatory factors, then we developed the clinical prediction model. Results One hundred fifty-two patients participated in the study: 94 patients in the normal bladder group and 58 patients in LCB group. Demographic data were not significantly different between the two groups, except diabetes. Cystometric capacity, detrusor pressure, compliance were significantly different. From the univariate analysis, DM status, duration of RRT, and passing < 100 mL of urine per day were related to LCB. We named the prediction model, the DUDi score based on the predictors (Duration of RRT, Urine volume/day, Diabetes). Higher scores predicted a higher risk of low-compliance bladder [P value = 0.464 according to the Hosmer-Lemeshow test, and the AUC was 0.87 (95% CI 0.81-0.92)]. Conclusions Our clinical prediction model is easy to use and provides a high predictive value that is appropriate for patients who have no known LUTD to identify low-compliance bladder. Trial registration number and date of registration for prospectively registered trials This study was approved by the Thai Clinical Trials Registry Committee on 09 February 2021. The TCTR identification number is TCTR20210209006.
The Journal of Urology, 1999
Data on the interrelationships of bladder compliance (BC), detrusor instability (DI), and bladder outflow obstruction (BOO) in elderly men with lower urinary tract symptoms (LUTS) are scarce and were therefore assessed in this study. Principle inclusion criteria for this study were men aged ജ50 years suffering from LUTS as defined by an International Prostate Symptoms Score (IPSS) of ജ7 and a peak flow rate (Q max ) of ഛ15 ml/sec. Patients with previous surgery of the bladder, prostate, or urethra as well as a pathological neurourological status were excluded from this study. The following parameters were studied in all patients: IPSS, prostate volume calculated by transrectal ultrasonography, free uroflow study, post-void residual volume determined by transurethral catheterization, and a multichannel pressure flow study (p QS ). A group of 170 men were included in the analysis. The mean BC in the overall group was 32 ± 2 ml/cm H 2 O (mean ± standard error of the mean [SEM]; range, 4-100 ml/cm H 2 O). In 36.5% of patients, BC was significantly reduced (ഛ20 ml/cm H 2 O), and in a further 37.1%, it ranged from 20 to 40 ml/cm H 2 O. BC decreased statistically significantly (p < 0.05) in patients with advanced age, lower Q max , higher voiding pressures, and larger prostates. In men with DI (n ס 61), mean BC was significantly lower (22 ± 3 ml/cm H 2 O) compared to those without (37 ± 3 ml/cm H 2 O; p ס 0.001; n ס 109). Patients with severe BOO as defined by a linear passive urethral resistance relationship of ജ3 (n ס 109), had a significantly lower BC (23 ± 2 ml/cm H 2 O) compared to those without or minimal obstruction only (39 ± 3 ml/cm H 2 O; p ס 0.0002; n ס 61).
Neurourology and Urodynamics, 2013
Background: There is an agreement to use simple formulae (expected bladder capacity and other age based linear formulae) as bladder capacity benchmark. But real normal child's bladder capacity is unknown. Aims: To offer a systematic review of children's normal bladder capacity, to measure children's normal maximum voided volumes (MVVs), to construct models of MVVs and to compare them with the usual formulae. Methods: Computerized, manual and grey literature were reviewed until February 2013. Epidemiological, observational, transversal, multicenter study. A consecutive sample of healthy children aged 5-14 years, attending Primary Care centres with no urologic abnormality were selected. Participants filled-in a 3-day frequency-volume chart. Variables were MVVs: maximum of 24 hr, nocturnal, and daytime maximum voided volumes. Factors: diuresis and its daytime and nighttime fractions; bodymeasure data; and gender. The consecutive steps method was used in a multivariate regression model. Results: Twelve articles accomplished systematic review's criteria. Five hundred and fourteen cases were analysed. Three models, one for each of the MVVs, were built. All of them were better adjusted to exponential equations. Diuresis (not age) was the most significant factor. There was poor agreement between MVVs and usual formulae. Nocturnal and daytime maximum voided volumes depend on several factors and are different. Conclusions: Nocturnal and daytime maximum voided volumes should be used with different meanings in clinical setting. Diuresis is the main factor for bladder capacity. This is the first model for benchmarking normal MVVs with diuresis as its main factor. Current formulae are not suitable for clinical use. Neurourol. Urodynam. # 2013 Wiley Periodicals, Inc.
Neurourology and Urodynamics, 2007
Aims: To study the effects of age and 24-h volume (V 24 ) on bladder diary measurements of voiding frequency (F 24 ) and functional bladder capacity (FBC) from an asymptomatic female population. Also, to use these data to develop clinical reference values. (We use FBC as a generic term for bladder diary volume-per-void measurements.) Materials and Methods: Computer-processed 3-day bladder diaries were collected from 161 females (median age: 46.6 years; range ¼ 19.6-81.8 years) claiming no urological symptoms, previous pelvic surgery and diseases and medications effecting urologic function. Regression analysis was used to investigate relationships among age, FBC and V 24 . Results: Both FBC and F 24 increase as V 24 increases (P < 0.0005). With aging, F 24 increases (P ¼ 0.026) and FBC may decrease slightly (P ¼ 0.02-0.08). There is a concave downward, curvilinear relationship between age and V 24 . We used multiple regression to generate tables of FBC and F 24 ''normal limits'' adjusted for these simultaneous influences of V 24 and age. Removing their relationships to age reduces the variability of FBC and F 24 reference values by 50% and 20%, respectively. Conclusions: Our finding, supported by others, that, with increasing V 24 , FBC increases more than F 24 suggests an adaptive mechanism that adjusts FBC to urine production to minimize changes in voiding frequency. We illustrate adjustment of reference values for age and V 24 by calculating traditional clinical ''normal limits.'' However, the probable large overlap between ''normal'' and ''abnormal'' suggests that it may be more useful to report bladder diary measurements as reference population percentiles rather than to designate them ''normal '' or ''abnormal.'' Neurourol. Urodynam. 26:341-349, 2007. ß 2007 Abbreviations: BDRT, Bladder Diary Research Team; DO, detrusor overactivity; F 24 , 24-hr voiding frequency; FBC, functional bladder capacity; P 24 , 24-hr urine production rate; UI, urge incontinence; V 24 , 24-hr urine volume; V avg , average volume-per-void; V min , minimum volume-per-void; V max , maximum volume-pervoid; V rng , range of voided volumes V max minus V min . Institutions at which work was performed:
International Neurourology Journal, 2022
Purpose: To identify more accurate predictors of upper urinary tract dilatation (UUTD) in neurogenic bladder (NB) children, we studied the relationship among urodynamic parameters at different bladder filling stages, detrusor leak point pressure (DLPP) and UUTD. Methods: A total of 158 children (3-16 years) with NB were included and then divided into 2 groups according to whether their NB diagnosis was complicated with UUTD: the UUTD group (39 patients) and those without UUTD group (control group, 119 patients). The bladder filling phase was divided into 3 equal parts: the early, middle, and end filling stages. The bladder compliance (BC) and detrusor pressure (△Pdet) at each phase and DLPP at the end filling stage were recorded. Results: A BC < 8 mL/cm H2O both in the middle and end stages is more specific than a BC < 9 mL/cm H2O in the end stage (72%, 73%, vs. 66%), and △Pdet > 8 cm H2O in the early stage, 20 cm H2O in the middle stage and 25 cm H2O in the end stage are more sensitive than △Pdet > 40 cm H2O in the end stage (82%, 85%, 85%, vs. 49%). A DLPP cutoff value of 20 cm H2O showed higher sensitivity for predicting UUTD than 40 cm H2O. Conclusions: Low BC and a high △Pdet in the middle and end filling stages are more accurate factors than classic indicators for predicting UUTD. In addition, a DLPP value of > 20 cm H2O in the end bladder filling stage shows high sensitivity.
PloS one, 2017
The objective of this study is to assess correlation between bladder wall mechanical properties obtained by ultrasound bladder vibrometry (UBV) and urodynamic study (UDS) measurements in a group of patients undergoing clinical UDS procedure. Concurrent UBV and UDS were performed on 70 patients with neurogenic bladders (56 male and 14 female). Bladder wall mechanical properties measured by UBV at different filling volumes were correlated with recorded detrusor pressure (Pdet) values. Mean, median and standard deviation of correlation values were calculated and the significance of these observations was tested. Bladder wall mechanical properties obtained by UBV as group velocity squared and elasticity showed high correlations with Pdet measured at different volumes (median correlation 0.73, CI: 0.64-0.80 and 0.72, CI: 0.56-0.82 respectively). The correlation of group velocity squared and elasticity with Pdet were both significantly higher than 0.5. The results of this study suggest th...