Total Bladder Volume Research Articles

The impact of bladder shape on the ultrasonographic measurement of bladder volume in children.

US is used for non-invasive assessment of bladder shape and for calculation of bladder volume. To evaluate the impact of bladder shape on the accuracy of US estimation of bladder volume in children and to calculate formulas for US estimation of volume for different bladder shapes. US was performed in 146 children (94 girls, 52 boys, age range 9 months to 17 years, median 7.9 years) referred for urodynamic investigation. Three bladder diameters were measured, and bladder shapes were categorized as round, ellipsoid, cuboid, triangular and undefined. Urine was collected, and total bladder volume calculated. Correction coefficients (k) were calculated for the whole sample and for each bladder shape using linear regression analysis. Round bladder shape was present in 23%, 25% showed a cuboid shape, 21% an ellipsoid shape, 25% a triangular shape, and 6% had an undefined shape. Correction (regression) coefficient (k) for the whole sample was 0.66 (SE = 0.011); for round bladder 0.561 (SE = 0.013), cuboid bladder 0.923 (SE = 0.012), ellipsoid bladder 0.802 (SE = 0.006), triangular bladder 0.623 (SE = 0.007), and for undefined shape 0.749 (SE = 0.048). Mean percentage errors when using different correction coefficients were significantly lower than errors when using k = 0.5 applied to our data. Bladder shape has considerable impact on the accuracy of US estimation of bladder volume in children. Correction coefficients should be used for volume measurements of different bladder shapes.

Suprapubic bladder drainage after extraperitoneal cystotomy

Objective: To observe the effects of cessation of continuous bladder drainage after short-term catheterization in women who had extraperitoneal cystotomies. Methods: The study population included 84 women, 78 of whom had retropubic urethropexies and six of whom had retropubic paravaginal repairs. Intentional cystotomy was done intraoperatively to assure ureteral patency, bladder integrity, and no inadvertent suture penetration into the bladder. All cystotomies were closed in two layers with 3-0 chromic suture. Suprapubic catheters were placed intraoperatively in all cases. In all women except four with gross hematuria, continuous bladder drainage was stopped and voiding trials were started within 24 hours after surgery. Suprapubic catheters were removed when women spontaneously voided 80% of total bladder volume. Results: Suprapubic catheters were discontinued on average 4.1 days after surgery (range 2.7–14.1 days). Average bladder volume at initial clamping of the suprapubic catheter was 382 mL (range 224–510 mL). At this volume the integrity of the cystotomy should have been challenged appropriately. The women were observed for a minimum of 3 months with no immediate or long-term complications. Conclusion: Extraperitoneal cystotomy in a nondependent portion of the bladder does not require continuous bladder drainage for more than 24 hours. This information should allow pelvic surgeons to be more liberal with intraoperative cystotomies if bladder integrity or ureteral patency needs to be confirmed.

Bladder compliance in neurologically intact women.

No data currently exist to define normal bladder compliance (C) in women. This study was undertaken to establish normative data for C in neurologically intact women and to determine if detrusor instability (DI) is associated with changes in C. The multichannel urodynamic tracings of 270 patients (195 stable, 75 unstable) were reviewed according to a standard written protocol. Vesical and abdominal pressures (Pves, Pabd) were measured during retrograde filling after a stable baseline was established (< 50 ml) and just prior to cessation of infusion. If a detrusor contraction occurred, measurements were taken during a 5-sec window preceding onset of contraction. The vesical volume used to calculate C was the total bladder volume determined by completely emptying the bladder at the end of cystometry. Compliance was calculated by dividing this volume by the change in detrusor pressure (Pdet). For the purpose of some analyses, infinite C, i.e., no observed rise in Pdet, was arbitrarily assigned a value of 1,000. Overall, 47.6% of women had no increase in Pdet with filling to maximum cystometric capacity (MCC) and had infinite C. Women with instability were significantly less likely to have infinite C than those with stable bladders (32% vs. 53%; P = 0.003). In 75% of women, C was > 130 ml/cm; in 90%, C was > 60 ml/cm; and in 95%, C was > 40 ml/cm. There were significant differences between the distribution of stable and unstable bladders above and below each of these percentile cutoffs. Only 2 women, both of whom had unstable bladders, had C < 20 ml/cm water. Ninety-five percent of neurologically intact women have C > 40 ml/cm, and nearly half have no increase in Pdet during filling to MCC. Patients with DI have significantly less compliant bladders than do those with stable bladders. If C is < 40 ml/cm, a woman is 16 times more likely to have DI. Decreased C may suggest the diagnosis of DI in patients with urge incontinence whose symptoms are not reproduced in the laboratory.

Bladder compliance in neurologically intact women

No data currently exist to define normal bladder compliance (C) in women. This study was undertaken to establish normative data for C in neurologically intact women and to determine if detrusor instability (DI) is associated with changes in C. The multichannel urodynamic tracings of 270 patients (195 stable, 75 unstable) were reviewed according to a standard written protocol. Vesical and abdominal pressures (Pves, Pabd) were measured during retrograde filling after a stable baseline was established (<50 ml) and just prior to cessation of infusion. If a detrusor contraction occurred, measurements were taken during a 5-sec window preceding onset of contraction. The vesical volume used to calculate C was the total bladder volume determined by completely emptying the bladder at the end of cystometry. Compliance was calculated by dividing this volume by the change in detrusor pressure (Pdet). For the purpose of some analyses, infinite C, i.e., no observed rise in Pdet, was arbitrarily assigned a value of 1,000. Overall, 47.6% of women had no increase in Pdet with filling to maximum cystometric capacity (MCC) and had infinite C. Women with instability were significantly less likely to have infinite C than those with stable bladders (32% vs. 53%; P = 0.003). In 75% of women, C was >130 ml/cm; in 90%, C was >60 ml/cm; and in 95%, C was >40 ml/cm. There were significant differences between the distribution of stable and unstable bladders above and below each of these percentile cutoffs. Only 2 women, both of whom had unstable bladders, had C <20 ml/cm water. Ninety-five percent of neurologically intact women have C >40 ml/cm, and nearly half have no increase in Pdet during filling to MCC. Patients with DI have significantly less compliant bladders than do those with stable bladders. If C is <40 ml/cm, a woman is 16 times more likely to have DI. Decreased C may suggest the diagnosis of DI in patients with urge incontinence whose symptoms are not reproduced in the laboratory. © 1996 Wiley-Liss, Inc.

How reliable is a single measurement of urinary flow in the diagnosis of obstruction in benign prostatic hyperplasia?

Twenty-six elderly patients with obstructive symptomatology and an initial low peak urinary flow rate (< 15 ml/s) were observed for 6 to 12 months. Repeated assessments were made of flow rates and residual volumes. Within patients variation of the maximal urinary flow was significant; the standard deviation (SD) varied from 0.8 to 5.5 ml/s. The SD varied with the mean peak flow rates and this suggests that the precision of a single determination of a patient's peak flow is inversely related to the peak flow itself. In all, 333 determinations of peak flow were obtained. Only 80% were below 2 SD of the mean Siroky nomogram. Multiple determinations were used to estimate the sensitivity rate for each patient, i.e. the proportion of peak flows that were less than 2 SD below the mean of Siroky's nomogram. The average sensitivity for all of the flow values was 0.813 when applied to voided volumes and increased only slightly to 0.838 when applied to total bladder volume. Given a prevalence of 0.70 of obstruction ascribed to benign prostatic hyperplasia (BPH) among elderly men, the positive predictive value of an abnormally low peak flow was 0.97. A single low peak flow based on assessment of voided volume may serve as an almost sure indication of obstruction. If a patient has a single normal peak flow rate, he still has a 0.31 probability of having evidence of obstruction in his following uroflow determinations. Using total bladder volume does not make a difference in most patients and is not worth the effort and discomfort. The only patients who require accurate residual measurements are those with a normal uroflow but clear-cut obstructive symptomatology or with borderline peak flow. The results of this study are relevant to everyday clinical practice and to the evaluation of studies on alternatives to surgery in BPH.

Postpartum voiding in the primiparous after vaginal delivery

To study the voiding pattern after a ‘normal’ vaginal delivery, uroflowmetry and residual urine (RU) measurements (ultrasonography) were performed at the first postpartum voiding and on the 3rd and 5th postpartum days in 51 primiparous women. The bladder volume and the RU were significantly increased, while the corrected (for volume differences) peak flow rate was significantly decreased in the immediate postpartum period. The RU was positively correlated to the total bladder volume (r=28, p=0.05), birthweight (r=0.29, p=0.04) and head circumference (r=0.37, p=0.01), indicating that overdistension of the bladder, possibly due to transiently impaired nervous function, caused by mechanical stress, may play a role. No parturients developed acute urinary retention, and the voiding pattern normalized within a few days. No urinary infections were diagnosed. No correlation could be established between the time from delivery to the first voiding and the voided volume or the total bladder volume, respectively. It is concluded that the emptying function is slightly impaired, which, however, seems to be of limited clinical significance, and that the time after delivery per se is a poor predictor of the bladder volume.

Transurethral incision of bladder neck for voiding dysfunction after radical hysterectomy: A report of 24 cases

Twenty-four women who had radical abdominal hysterectomy, and subsequently developed persistent high post-void residual urine underwent transurethral bladder neck incision. Persistent high post-void residual urine is defined as a residual urine volume 20% greater than the amount just voided. This was determined during a 24-hour period, 3 months or more after the radical hysterectomy. Our results indicated that the bladder outlet resistance before and after the procedure was 0.96±1.01 and 0.19±0.07 respectively (P<0.05). The mean ratios between residual urine and total bladder volume in 24 cases were reduced from 93.45±42.93% to 33.47±22.79% after the procedure (P<0.001). In addition, there was a significant decrease of functional urethral length, maximal urethral closure pressure and bladder outlet resistance. Based on the ratios of residual urine and total bladder volume, 7 patients were markedly improved, 10 were partially improved, 7 remained unchanged and none worsened. The overall improvement rate was 71% (17/24). Urinary incontinence was a rare complication which occurred in only one woman (4%).

Residual urine volume following involuntary voiding in elderly inpatient men

AbstractUrinary incontinence is a debilitating condition for elderly inpatients. The etiology is not well understood and has not been investigated extensively. Incontinence volume per episode has been shown to vary within patients and does not appear to be associated with cystometric bladder capacity. The objective of this study was to determine the relationship of residual urine volume following involuntary voiding to the incontinence volume and the total bladder volume in elderly inpatient men. Sixteen patients had catheterized residual urine volume measurements done following involuntary voiding on each of four days. Significant variability was found in the residual urine volume, the incontinence volume, and the total bladder volume within patients having urinary incontinence. The variability observed in volume parameters suggests that factors other than intravesical volume may have a significant role in the etiology of involuntary voiding in elderly patients.

Accuracy of total bladder volume and residual urine measurements: Comparison between real-time ultrasonography and catheterization

The practical value of ultrasonography as a rapid means to accurately determine total bladder volumes and residual urine volume was assessed. Transverse and sagittal bladder diameters were measured with real-time ultrasonography in 50 women: (1) before uroflowmetry, (2) before supine-postvoiding catheterization, (3) before standing catheterization, and (4) after standing catheterization. Calculated bladder volumes, by use of the measured diameters, for each of eight formulas from the literature were compared with their corresponding measured total urine volume, total residual volume, and standing residual volume. The lower limit of ultrasonographic visualization of urine in the bladder was approximately 42 ml. No correlation existed between calculated ultrasound bladder volumes and measured urine volumes for any of the eight formulas. Standing residual volumes were measured in 96% of cases. Ultrasonography cannot as yet rapidly measure bladder volumes accurately. Catheterization remains the best method of assessing postvoid residuals: supine measurements, the gold standard, should be augmented by standing measurements when more accurate volumes are required.

Clinical Evaluation of Patients with Prostatic Obstruction: Correlation of Flow Rates With Voided, Residual or Total Bladder Volume

Previous investigators reported that accurate estimation of average or maximum urinary flow rates required correlation with total bladder volume (voided plus residual volumes). To test this requirement we performed uroflowmetry studies on 124 patients before and 77 patients after prostatectomy. Of the patients 20 were tested on multiple preoperative and postoperative occasions to comprise paired observations. Observations were made on age, voided and residual volumes, voiding duration, and average, maximum and adjusted maximum flow rates. Prostatectomy resulted in significant increases in all flow rates and significant decreases in voiding duration. The procedure had significant effects on reducing residual volume but voided volumes increased and total volume decreased only slightly postoperatively. Preoperative average, maximum and adjusted peak urinary flow rates correlated negatively with residual volume (increasing residual volume correlates with decreasing flow rate). Maximum flow rates correlated positively with voided volume. Whether measured preoperatively or postoperatively no significant correlation was found among average, peak or adjusted flow rates and total bladder volume. The only consistent significant correlation found among voided, residual and total volumes, and other measurements was voiding duration, which increased as any of the aforementioned volumes increased. Comparison of the random total and paired populations revealed no significant difference. Use of voided rather than total volume seems preferred in correlations with maximum urinary flow rates. Determination of residual urine remains necessary as an estimation of emptying failure but it is not required information for determination of flow rates.