Intrapartum ultrasound estimation of total bladder volume

Micturition in the toilet compared with bedpan in laboring Nulliparas: a randomized controlled trial

Background

Bladder overdistension in labor may lead to prolonged postpartum urinary retention. We hypothesized that nulliparas mobilizing to toilet is more likely to achieve satisfactory micturition.

Methods

One hundred sixteen (58 in each arm) term nulliparas in labor with filled bladders were randomized to mobilizing to the toilet or using bedpan to micturate. Primary outcome was satisfactory micturition defined as ultrasound derived post-void bladder volume < 150 ml. Following unsatisfactory micturition, participants crossover to the opposed intervention. Participants were catheterized if after crossover, residual bladder volume was ≥250 ml.

Results

Satisfactory micturition rates were 55/58 (95%) vs. 43/58 (74%) RR 1.28 95%CI 1.08–1.51 NNTb 4.8 95%CI 3.0–12.4 P = 0.008, failure to micturate 1/58 (2%) vs. 8/58 (14%) RR 0.13 95%CI 0.02–0.97 NNTb 8.3 95%CI 4.6–38.7 P = 0.047. After cross over following unsatisfactory bladder voiding, satisfactory micturition rates were 0/3 (0%) vs 13/15 (87%) P = 0.024, bladder catheterization rates were 3/58 (5%) vs. 2/58 (4%) RR 95%CI 1.5 (0.26–8.65) P = 0.648, maternal satisfaction with allocated intervention 55/58 (95%) vs. 9/58 (16%) RR 95%CI 6.1 (3.3–11.2) NNTb 95%CI 1.3 (1.1–1.5) P <  0.0001 and preference for mobilizing to the toilet if micturition was needed again during labor 55/58 (95%) vs. 53/58 (92%) for mobilizing to the toilet compared to bedpan use arms respectively. Labor and neonatal outcomes were similar.

Conclusion

Satisfactory micturition was more frequently achieved with mobilization to the toilet than bedpan use. Women in both arms overwhelmingly prefer to mobilize to the toilet to urinate.

Trial registration

This study was registered with ISRCTN on 17/07/2019 with trial identification number: ISRCTN17787339. First participant was recruited on 31/07/2019. The last patient was recruited on 18/12/2019.

A comprehensive survey on non-invasive wearable bladder volume monitoring systems

Measuring the volume of urine in the bladder is a significant issue in patients who suffer from the lack of bladder fullness sensation or have problems with timeliness getting to the restroom, such as spinal cord injury patients and some of the elderlies. Real-time monitoring of the bladder, therefore, can be highly helpful for urinary incontinence. Bladder volume monitoring technologies can be divided into two distinct categories of invasive and non-invasive. In invasive techniques, a catheter is directly inserted into the urethra to measure the amount of urine accurately. However, it is painful, limits the user's ordinary movements, and may hurt the urinary tract. Current non-invasive techniques measure the volume of the bladder from the skin using different stationary or portable apparatus at health centers. Both techniques have difficulties and are not cost-effective to use for a long period. Recently, both invasive and non-invasive methods have been attempted to be produced in the form of wearable devices utilizing different sensing and communication technologies. Wearable bladder monitoring devices can be easily used by patients with no or few clinical steps, making them much more affordable than non-wearable devices. While wearable devices seem to be a highly convenient and effective solution, they suffer from few drawbacks, such as relatively low precision. Hence, a great number of studies have been conducted to address these issues. In this article, we review and discuss non-invasive and minimally invasive methods for monitoring the bladder volume. We focus on the most practical and state-of-the-art methods employed in wearable devices, classify them by engineering and medical characteristics, and investigate their specifications, architectures, and measurement algorithms. This study aims to introduce the latest advances in this field to practitioners while comparing the advantages and disadvantages of existing approaches. Our study concludes with open problems and future trends in the area of bladder monitoring and measurement systems. Graphical abstract Wearable bladder monitoring system.

The role of bladder volume in the success of external cephalic version

OBJECTIVE

Numerous studies have evaluated the factors associated with ECV success. Yet, bladder volume has never been examined. We hypothesize that maternal bladder volume may affect ECV success rate. We aim to evaluate the role of maternal bladder volume during external cephalic version (ECV) on the procedure success rates.

STUDY DESIGN

We reviewed prospective collected data of all patients who underwent ECV at our center during 2001-2012. The study group included 100 patients that underwent ECV with bladder volume below 400 ml. These patients were matched to 400 patients that underwent ECV with bladder volume equal or above 400 ml which composed the control group. Maternal and fetal characteristics and outcomes were compared.

RESULTS

ECV was successfully performed in 80/100 (80.0%) of patients in the study group as compared to 257/400 (64.3%) in the control group (P = 0.002). Factors associated with ECV success were older age (P = 0.003), having prior delivery (P < 0.0001), higher amniotic fluid index (AFI) (P = 0.001) and placenta located in the posterior wall (P = 0.001). In a logistic regression analysis, bladder volume was found to be an independent predictor of ECV success Odds radio (OR) for ECV success 2.5 (CI 1.42-4.34). Posterior placenta and higher AFI were found to be an independent predictors of ECV success as well; OR 2.7 (CI 1.74-4.34) and OR 1.07 (CI 1.02-1.13) respectively.

CONCLUSION

ECV is more successful in patient with bladder volume below 400 ml. Amniotic fluid volume and placental location were found as independent predictors of ECV outcome as well.

Postpartum urinary retention: Evaluation of risk factors

Objective

Postpartum urinary retention means the absence of spontaneous micturition more than 6 hours after birth or when residual volume after urination is less than 150 cc. If neglected, postpartum urinary retention may result in bladder denervation and detrusor muscle weakness requiring intermittent catheterization or permanent micturition dysfunction. Our goal was to identify the possible risk factors for postpartum urinary retention.

Materials and Methods

Five hundred sixty female subjects were included in this retrospective study. All data obtained including variables such as age, parity, body mass index, duration of labor, prepartum bladder catheterization were compared between female subjects with and without postpartum urinary retention.

Results

Among the 560 patients recruited to our study, 124 (22.1%) had postpartum urinary retention. Third stage duration, time from birth to the first void, and number of peripartum micturitions were found to be potential risk factors for postpartum urinary retention. Different than other studies, our study revealed a correlation between peripartum catheterization and postpartum urinary retention. There were no statistically significant differences between patients with and without postpartum urinary retention in terms of other variables.

Conclusion

In this study, a correlation between peripartum catheterization and postpartum urinary retention was found. There are studies that reported the possible risk factors related to the occurrence of postpartum urinary retention. More studies should be conducted to investigate long-term results with larger populations.

Neuroanatomic and behavioral correlates of urinary dysfunction induced by vaginal distension in rats

The aim of the present study was to use a model of simulated human childbirth in rats to determine the damage to genitourinary structures and behavioral signs of urinary dysfunction induced by vaginal distension (VD) in female rats. In experiment 1, the length of the genitourinary tract and the nerves associated with it were measured immediately after simulated human delivery induced by VD or sham (SH) procedures. Electroneurograms of the dorsal nerve of the clitoris (DNC) were also recorded. In experiment 2, histological characteristics of the bladder and major pelvic ganglion of VD and SH rats were evaluated. In experiment 3, urinary parameters were determined in conscious animals during 6 h of dark and 6 h of light before and 3 days after VD or SH procedures. VD significantly increased distal vagina width (P < 0.001) and the length of the motor branch of the sacral plexus (P < 0.05), DNC (P < 0.05), and vesical nerves (P < 0.01) and decreased DNC frequency and amplitude of firing. VD occluded the pelvic urethra, inducing urinary retention, hematomas in the bladder, and thinness of the epithelial (P < 0.05) and detrusor (P < 0.01) layers of the bladder. Major pelvic ganglion parameters were not modified after VD. Rats dripped urine in unusual places to void, without the stereotyped behavior of micturition after VD. The neuroanatomic injuries after VD occur alongside behavioral signs of urinary incontinence as determined by a new behavioral tool for assessing micturition in conscious animals.

Ultrasound estimation of female bladder volume based on magnetic resonance modeling

PURPOSE

We developed a precise method to noninvasively and conveniently measure female bladder volume greater than 100 ml by ultrasound.

MATERIALS AND METHODS

Using the proposed method bladder magnetic resonance measurements were made in 7 healthy women to create the volume estimation model. To validate the model for ultrasound application bladder ultrasound images were scanned in 23 healthy women and corresponding volumes were calculated. Calculated and true volumes were compared with the Pearson correlation coefficient and Bland-Altman plots.

RESULTS

A total of 51 bladder magnetic resonance images were segmented and reconstructed as 3-dimensional objects. Of the 51 objects 24 had a volume of greater than 100 ml. Based on the 24 objects we regressed the new equation, V = 7.1 x Dl x H - 23, where V represents estimated volume, Dl represents bladder depth and H represents bladder height measured by the proposed method. The estimation was statistically significant (SE 44, r(2) 0.94, p <0.001). A total of 69 ultrasound measurements were made and corresponding volumes were calculated by the equation. The sum of voided and post-void residual volume, when there was any, was considered true volume (range 140 to 995 ml). A significant relationship was found between true and calculated volume (mean difference -3 ml, mean absolute difference 23, r(2) = 0.97, p <0.01). The Bland-Altman 95% limits of agreement were -57 to 51 ml.

CONCLUSIONS

The proposed method performs well to estimate female bladder volume greater than 100 ml.

Post-void residual volume in labor: a prospective study comparing parturients with and without epidural analgesia

BACKGROUND

This prospective, non-randomized study compared post-void residual volume in laboring and postpartum women with or without epidural analgesia.

METHODS

The study was conducted over 1 year with institutional review board approval. Parturients were recruited in early labor and self-selected to either the study (with epidural) or control (without epidural) group. Post-void residual volume was compared between groups, using transabdominal ultrasound during labor, and on postpartum day 1 and 2. Main outcome measure was intrapartum residual bladder volume.

RESULTS

Thirty patients were recruited to each group. During labor, residual bladder volume was significantly larger in the epidural group compared with the non-epidural group [median (range)] 240 (12-640), ml vs. 45 (13-250) ml, respectively, P < 0.001], but was similar on postpartum day 1 and 2. Twenty-five (83%) women with epidural analgesia required bladder catheterization during labor vs. one (3.3%) without (P < 0.0001).

CONCLUSION

The greater post-void residual volume and increased inability to void in parturients with epidurals suggests that epidural analgesia plays a role in intrapartum urinary retention.

Patient-controlled epidural analgesia: the role of epidural fentanyl in peripartum urinary retention

BACKGROUND

Urinary bladder function is impaired during labor and delivery, predisposing to urinary retention. The effect of low-dose epidural opioid on bladder function remains unclear. We tested the hypothesis that adding low-dose fentanyl to epidural ropivacaine for patient-controlled labor analgesia does not promote urinary retention.

METHODS

Laboring women who requested patient-controlled epidural analgesia were randomly assigned in a double blind study to 0.2% ropivacaine (R-group, n=100) or 0.2% ropivacaine with fentanyl 2 microg/mL (RF-group, n=98). Urinary bladder distension was assessed clinically every hour. The post-void residual urine volume was measured by ultrasonography. Urine volume exceeding 100 mL was drained by catheterization. Bladder volume of > or =300 mL, as determined by catheterization was considered as evidence of urinary retention.

RESULTS

Thirty percent of the patients in each group developed urinary retention during labor. There was no statistically significant difference between the groups. There was an excellent correlation between bladder volume as estimated by ultrasonography and that by catheterization: catheterization volume=0.93 x ultrasound volume + 25; r(2)=0.83. The bias (mean error) was -1+/-99 mL and the precision (average absolute error) between the ultrasound estimate and actual bladder volume determined by catheterization was 58+/-79 mL.

CONCLUSION

Addition of fentanyl to patient-controlled epidural analgesia did not increase the risk of urinary retention. Ultrasound measurements were effective and reliable in assessing urinary bladder volumes during labor.