Bladder Pressure Measurement Research Articles

Does sheath size matter: benchtop comparison of flow and pressure across variety of continuous flow endoscopes.

Laser enucleation utilizes purpose-built endoscopes for laser stabilization and continuous flow. No evaluation has been done with respect to flow or intravesical pressure with these scopes. We sought to evaluate the effect different endoscopes and sheath sizes on irrigation outflow and intravesical pressure. Using a benchtop model using a silicone bladder model, five outer/inner sheath combinations were assessed: Storz 28/26Fr, Storz 26/26Fr, Wolf 26/24Fr, Wolf 26/22Fr, and Wolf 24/22Fr. A urodynamics pressure transducer was inserted alongside the scope for bladder pressure measurement and outflow from scope to drain was measured using uroflowmetry device. Four 1-minute trials were recorded for each sheath and the steady state flow and pressure was recorded. The Storz 28F outer sheath and 26F inner sheath had the highest outflow (12.4 ± 0.5 mL/s, p < 0.01). The Wolf 24F outer and 22F inner had the lowest outflow (7.0 ± 0.0 mL/s, p < 0.01). The steady state bladder pressure was the lowest in the Storz 28/26 (1.5 ± 1.7cm H2O, p < 0.01)) and the greatest in the Storz 26/26 (24.2 ± 1.9cm H2O, p < 0.01). The Storz 28/26 combination had best outflow rate and lowest intravesical pressures in our benchtop study. Flow rates generally decreased with smaller sheath sizes and steady state bladder pressures increased as the difference between the outflow and inflow sheath size narrowed. These findings provide initial parameters that could guide sheath selection in future to optimize visualization and success of voiding trials.

A novel technique for atraumatic transurethral catheterisation of male rats.

Transurethral catheterisation of male rats is technically difficult owing to anatomical peculiarities. In the male rat, the urethral striated sphincter consists of two lateral fascicles separated by an anterior and a posterior strip of connective tissue, which impedes the smooth insertion of a urinary catheter. For rat studies requiring continuous collection of urine, bladder irrigation, or measurement of bladder pressure, investigators either have to exclude the male population (be limited to the female population) or perform percutaneous (suprapubic) bladder puncture in male rats, which is more traumatic and invasive than transurethral catheterisation. This paper describes a novel, atraumatic method of transurethral catheterisation in the male rat, with the aid of a microscope and microsurgical instruments. Six Wistar rats were used for this experiment, all of which were catheterised successfully, with no evidence of bladder or urethral injury. The study shows that male rats can be safely catheterised via the urethra with the aid of a microscope and microsurgical instruments for both visual and tactile feedback. This is a relatively straightforward technique to learn and can allow for inclusion of male rats in future studies requiring urinary analysis or bladder irrigation, without the need for traumatic percutaneous (suprapubic) bladder puncture.

Abdominocentesis and intra-abdominal pressure measurement in small animals.

To provide a video tutorial detailing how to perform "blind" and ultrasound-guided abdominocentesis for diagnostic and therapeutic guidance, and to provide a brief demonstration of intra-abdominal pressure measurement (IAP). Any cat or dog with suspicion of free abdominal effusion or patients requiring measurement of IAP. Abdominocentesis should be performed when there is high suspicion for peritoneal effusion based on physical exam and/or diagnostic imaging. The 4-quadrant tap uses 20-gauge or larger needles placed blindly in ≥ 1 of the 4 quadrants of the abdomen to collect abdominal fluid. In contrast, ultrasound allows visualization of fluid in the abdomen prior to percutaneous insertion of a needle and syringe to collect fluid. Regardless of collection technique, fluid should have immediate cytologic analysis and later can be submitted for biochemical parameters, additional cellular analysis by a pathologist, and culture and sensitivity (in rare cases if indicated). Intravesicular bladder pressure measurement using a manometer-urinary catheter system approximates the IAP when there is concern for organ hypoperfusion and compartment syndrome. Abdominocentesis can be performed with and without the use of ultrasound guidance. Intravesicular bladder pressure measurement is used to diagnose and trend IAP values before and after treatments are performed. Abdominocentesis is a simple and safe technique that all small animal clinicians should be comfortable performing. Effusion sampling can guide further diagnostics and treatments. Measurement of IAP is simple and requires no specialized equipment.

A Comparative Study of Commercially Available Ultrasound Contrast Agents for Sub-harmonic-Aided Pressure Estimation (SHAPE) in a Bladder Phantom

ObjectiveThe goal of this study was to evaluate the performance of different commercial ultrasound contrast microbubbles (MBs) when measuring bladder phantom pressure with sub-harmonic-aided pressure estimation (SHAPE) methodology. We hypothesized that SHAPE performance is dependent on MB formulation. This study aimed to advance the SHAPE application for bladder pressure measurements in humans. MethodsUsing a previously designed and built bladder phantom, we tested four different commercial agents: Definity, Lumason, Sonazoid and Optison. A standard clinical cystometrogram (CMG) system was used to infuse a MB–saline mixture into the bladder phantom to measure pressure. Ultrasound imaging was performed using the GE Healthcare LOGIQ E10 scanner. ResultsAll agents showed a predicted inverse linear relationship between change in pressure and SHAPE signal. However, they differ from each other in terms of stability, linear correlation, sensitivity to pressure and error. Generally, Definity and Lumason showed the highest performance during the SHAPE-based bladder phantom pressure assessments. ConclusionOur results show that the SHAPE signal decreases as bladder phantom pressures increases, regardless of the agent or CMG phase, suggesting the possibility of using SHAPE for measuring bladder pressure without a catheter. However, the efficacy of SHAPE in measuring pressure varies by MB formulation. These observations support using Lumason and Definity in a human subject feasibility study as we advance toward a catheter-free solution for measuring voiding bladder pressure via SHAPE.

Abdominal compartment syndrome in visceral surgery and intensive care medicine : Causes, prevention, detection, treatment

An increased intra-abdominal pressure can result in amanifest abdominal compartment syndrome (ACS) with significant organ damage, which is a life-threatening situation associated with ahigh mortality. Although the etiology is manifold and critically ill patients on the intensive care unit are particularly endangered, the disease is often not diagnosed even though the measurement of bladder pressure is available as a simple and standardized method; however, particularly the early detection of an increased intra-abdominal pressure is decisive in order to prevent the occurrence of a manifest ACS with (multi)organ failure by means of conservative measures. In cases of a conservative refractory situation, decompressive laparotomy is indicated.

Abdominal Compartment Syndrome: Definitions, Epidemiology, and Management

Abdominal compartment syndrome (ACS) is a multifaceted and potentially life-threatening medical condition characterized by elevated intra-abdominal pressure. While ACS was initially associated with trauma, it has become evident that this syndrome can manifest in various clinical scenarios.&#x0D; The prevalence of ACS varies across diverse patient populations and clinical settings. Risk factors such as obesity, intra-abdominal tumors, ascites, and major surgery heighten the vulnerability to developing ACS. The pathophysiology of ACS involves a cascade of events compromising organ perfusion. This includes the compression of the inferior vena cava and renal veins, leading to reduced venous return and impaired renal blood flow, which can result in renal failure.&#x0D; Accurate diagnosis of ACS relies on the measurement of intra-abdominal pressure, often performed through bladder pressure measurement. Management encompasses a range of supportive measures, careful patient positioning, ventilatory support, and strategies to reduce intra-abdominal volume. Surgical decompression becomes necessary when conservative approaches fail, although this decision must consider individual patient factors.&#x0D; This review underscores the evolving landscape of ACS and emphasizes the imperative for continued research to address uncertainties in pathophysiology, diagnostic criteria, and management strategies. Enhanced understanding and refined approaches hold the potential to significantly improve outcomes for at-risk or affected patients.

Effect of photobiomodulation on lower urinary tract dysfunction in rat cystitis model.

Photobiomodulation selectively controls the activity of the sensory nervous system associated with A-delta and C fibers. Hypersensitivity involving the afferent A-delta and C fibers occurs in cystitis and decreases urinary function. This study aimed to investigate the effect of photobiomodulation on urinary storage dysfunction and voiding functions in cystitis model rats. We prepared the rat cystitis model. Under anesthesia, a cannula was connected to the bladder via a ventral incision. 0.3% acetic acid or saline was injected into the bladder. Continuous cystometry was performed, measuring bladder pressure and voiding urine volume with rats freely mobile. Laser irradiation was applied to the L6 lumbosacral intervertebral foramen using an 830 nm laser. Residual urine was extracted post-cystometry. In the rat cystitis model groups, there was a significant decrease in the voiding interval and volume compared to the group receiving normal saline infusion. After sham or laser irradiation, only the group with laser irradiation showed a significant increase in voiding interval (217%, p = 0.0002) and voiding volume (192%, p = 0.0012) in the parameters of storage dysfunction. The basal pressure, intravesical pressure, and residual urine volume remained unchanged in all groups before and after irradiation. This study indicates that photobiomodulation may improve urine storage dysfunction without exacerbating voiding function in a rat model of cystitis. Thus, photobiomodulation may be a new treatment option for the hypersensitivity and detrusor overactivity caused by cystitis.

Can cardiac pressure-volume catheters improve urodynamic assessment? an ex-vivo proof-of-concept

AimsTo explore the feasibility of using pressure-volume (PV) catheters for cystometry. These catheters are well-established in cardiovascular research for simultaneous pressure and volume measurements in the left ventricle.MethodsUrinary bladders with urethras were collected from domestic pigs for ex-vivo testing. Using a pump, bladders were filled up to 500ml at five different filling rates (15, 20, 25, 30, 35ml/min), and the resulting pressures and volumes were measured using a PV catheter. The bladder were compressed externally in three different areas (central, apex and outlet) to assess the PV catheter’s ability to detect local changes in bladder volume.ResultsBladder pressure remained below 10cmH2O for all bladder filling rates. Volume measurements were compared with the volumes instilled by the pump (ground truth), proving high reproducibility and accuracy of the PV catheter measurements up to 400ml. Using the different sensing units of the PV catheter, local changes in bladder volumes could be identified and quantified.ConclusionThe main advantage of PV catheters, compared to existing technology used in urology (e.g. conventional urodynamic testing), is the possibility to i) simultaneously measure bladder pressure and volumes and ii) identify local changes in bladder volume (e.g. caused by non-voiding contractions). Both could be useful in the clinical setting to improve the diagnosis and treatment of the Lower Urinary Tract Dysfunction (e.g. overactive/underactive bladder).

PD23-11 CATHETER-FREE BLADDER PHANTOM PRESSURE MEASUREMENT-COMPARISON STUDY OF COMMERCIAL ULTRASOUND CONTRAST AGENTS

You have accessJournal of UrologyCME1 Apr 2023PD23-11 CATHETER-FREE BLADDER PHANTOM PRESSURE MEASUREMENT-COMPARISON STUDY OF COMMERCIAL ULTRASOUND CONTRAST AGENTS Kourosh Kalayeh, J. Brian Fowlkes, Amy Chen, Sophia Yeras, Mario L. Fabiilli, William W. Schultz, and Bryan S. Sack Kourosh KalayehKourosh Kalayeh More articles by this author , J. Brian FowlkesJ. Brian Fowlkes More articles by this author , Amy ChenAmy Chen More articles by this author , Sophia YerasSophia Yeras More articles by this author , Mario L. FabiilliMario L. Fabiilli More articles by this author , William W. SchultzWilliam W. Schultz More articles by this author , and Bryan S. SackBryan S. Sack More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003296.11AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Measuring voiding bladder pressure is a major challenge in urodynamic testing. The indwelling urethral catheter blocks flow of urine, causing elevated pressures and lower flow. We previously have shown that ultrasound contrast agents (UCAs) can reliably estimate bladder phantom pressures (BPP), through a technique called subharmonic-aided pressure estimation (SHAPE). We hypothesize that SHAPE performance in measuring BPP varies by UCA formulation. METHODS: Four different UCAs were considered (DEFINITY, Lumason, Sonazoid, and OPTISON). Each UCA was diluted in 0.9% normal saline and infused into the bladder phantom using cystometrogram (CMG) equipment (30 mL/min). For each UCA, simultaneous with pressurization, the UCA subharmonic (SH) signal was acquired with a GE LOGIQ E10 ultrasound scanner equipped with SHAPE. This was performed during infusion–filling event–and two post-filling events–PF1: immediately after infusion, and PF2: 5 min later. The change in BPP and SH signal were correlated and a linear regression model (lrm) was used to find the SHAPE sensitivity in dB/cmH2O. The UCA performances were compared in terms of i) SH signal longevity, ii) linear correlation of lrm, iii) sensitivity for BPP measurement, and iv) accuracy–root mean square error of lrm. RESULTS: SHAPE performance is summarized in Table 1. DEFINITY and Lumason show better performance, see examples of Figure 1. For every UCA (except OPTISON) SHAPE sensitivity showed time-dependent behavior. No statistically significant difference was found between SHAPE sensitivities of different CMG events for Lumason. For DEFINITY and Sonazoid SHAPE sensitivity for PF2 was significantly higher than the filling event. CONCLUSIONS: For every UCA and CMG event the SH signal decreases with increase in BPP. As hypothesized, SHAPE performance is dependent on the UCA. These findings will help in UCA selection for further evaluation of this method in human subjects and taking the next steps toward developing a catheter-free voiding bladder pressure measurement using SHAPE. Source of Funding: This research has been partially supported by grants from The Societies for Pediatric Urology (SPU), the University of Michigan Mcubed program, the Michigan Institute for Clinical and Health Research (MICHR), and the Departments of Urology and Radiology at the University of Michigan. The support for ultrasound scanner used in this study (GE LOGIQ E10) comes from General Electric Healthcare (Wauwatosa, WI, USA) © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e676 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kourosh Kalayeh More articles by this author J. Brian Fowlkes More articles by this author Amy Chen More articles by this author Sophia Yeras More articles by this author Mario L. Fabiilli More articles by this author William W. Schultz More articles by this author Bryan S. Sack More articles by this author Expand All Advertisement PDF downloadLoading ...

Reproducibility evaluation of air-charged catheter for rest urethral pressure profilometry

We retrospectively included 53 (9 males, 44 females) patients who underwent rest urethral pressure profilometry (RUPP) due to lower urinary tract symptoms (LUTS) in Beijing Chaoyang Hospital from May 2021 to March 2022. The age of patients was (55±16) (25-76) years old. The clinical diagnoses of the included patients with lower urinary tract symptoms were classified as: benign prostatic hyperplasia in 9 cases, interstitial cystitis in 1 case, stress urinary incontinence in 11 cases and non-obstructive dysuria in 32 cases. The full set of urodynamic examination was composed of bladder pressure measurement during the filling period, pressure flow study (PFS) and RUPP. All the urodynamic examination was performed by air-charged catheter (ACC) and corresponding equipment. All patients underwent RUPP measurements twice. The vesical pressure (Pves) values were (35.30±6.15), (35.81±5.91) cmH2O (1 cmH2O=0.098 kPa); the Pura@max were (141.91±36.53), (145.02±38.85) cmH2O; functional urethral length were (41.70±16.34), (42.55±16.40) mm; the maximum urethral closure pressure for the two RUPP measurements were (106.57±36.44), (109.41±39.27) cmH2O. There was no statistical difference between the two RUPP measurements (P>0.05). The reproducibility of the RUPP measurements obtained by ACC is good and deserves further study.

Ultrasound Contrast Stability for Urinary Bladder Pressure Measurement.

The goal of this study was to evaluate ultrasound contrast microbubbles(MB) stability during a typical cystometrogram(CMG) for bladder pressure measurement application using the subharmonic-aided pressure estimation technique. A detailed study of MB stability was required given two unique characteristics of this application: first, bulk infusion of MBs into the bladder through the CMG infusion system, and second, duration of a typical CMG which may last up to 30 min. To do so, a series of size measurement and contrast-enhanced ultrasound imaging studies under different conditions were performed and the effects of variables that we hypothesized have an effect on MB stability, namely, i) IV bag air headspace, ii) MB dilution factor, and iii) CMG infusion system were investigated. The results verified that air volume in intravenous(IV) bag headspace was not enough to have a significant effect on MB stability during a CMG. We also showed that higher MB dosage results in a more stable condition. Finally, the results indicated that the CMG infusion system adversely affects MB stability. In summary, to ensure MB stability during the entire duration of a CMG, lower filling rates(limited by estimated bladder capacity in clinical applications) and/or higher MB dosage(limited by FDA regulations and shadowing artifact) and/or the consideration of alternative catheter design may be needed.

Influence of cerebral infarction on both bladder and urethral activities and changes after tramadol administration in rats.

We investigated the changes in bladder and urethral function after cerebral infarction (CI) and the influence of tramadol on these functions. Twenty-eight female Sprague Dawley rats were divided into normal and CI groups. In the awake condition, metabolic cage study and blood pressure were evaluated. Under urethane anesthesia, the intravenous effect of tramadol (0.01-1 mg/kg), which has both µ-opioid receptor stimulation and inhibition of norepinephrine and serotonin reuptake, on continuous cystometry, and simultaneous measurements of bladder and urethral perfusion pressure (UPP) were recorded. Infarcted lesions were examined by staining with triphenyltetrazolium chloride, a marker of mitochondrial enzyme activity. CI rats showed impaired sympathetic activity with Horner's syndrome and lower blood pressure. In metabolic cage study, urinary frequency during the dark phase was increased in CI rats. On bladder activity, in CI rats, the baseline pressure threshold for inducing bladder contractions was significantly lower (p &lt; 0.01), and the intercontraction interval was prolonged after tramadol administration. On urethral activity, the baseline UPP was significantly lower in CI rats than in normal rats and it did not change after tramadol administration. Residual urine rate was significantly increased in normal rats, but not in CI rats. CI rats showed brain infarction including the cortex and hypothalamus, which is a center of the autonomic nervous system. CI-induced ischemic brain damage results in impairment of both bladder and urethral functions, in addition to decreased sympathetic activity. Bladder overactivity after CI can be improved by tramadol; however, urethral activity cannot be improved by it.

Pressure Measurement in a Bladder Phantom Using Contrast-Enhanced Ultrasonography-A Path to a Catheter-Free Voiding Cystometrogram.

The long-term goal of this study is to investigate the efficacy of a novel, ultrasound-based technique called subharmonic-aided pressure estimation (SHAPE) to measure bladder pressure as a part of a cystometrogram (CMG) in a urodynamic test (ie, pressure-flow study). SHAPE is based on the principle that subharmonic emissions from ultrasound contrast microbubbles (MBs) decrease linearly with an increase in ambient pressure. We hypothesize that, using the SHAPE technique, we can measure voiding bladder pressure catheter-free. This is of importance because the CMG catheter, due to its space-occupying property and non-physiological effects, can undermine the reliability of the test during voiding and cause misdiagnosis. In this study, we tested this hypothesis and optimized the protocol in a controlled benchtop environment. A bladder phantom was designed and built, capable of simulating clinically relevant bladder pressures. Laboratory-made lipid-shelled MBs (similar in composition to the commercial agent, DEFINITY) was diluted in 0.9% normal saline and infused into the bladder phantom using the CMG infusion system. A typical simulated CMG consists of 1 filling and 4 post-filling events. During CMG events, the bladder phantom is pressurized multiple times at different clinically relevant levels (small, medium, and large) to simulate bladder pressures. Simultaneous with pressurization, MB subharmonic signal was acquired. For each event, the change in MB subharmonic amplitude was correlated linearly with the change in bladder phantom pressure, and the SHAPE conversion factor (slope of the linear fit) was determined. In doing so, a specific signal processing technique (based on a small temporal window) was used to account for time-decay of MB subharmonic signal during a simulated CMG. A strong inverse linear relationship was found to exist between SHAPE and bladder phantom pressures for each of the CMG filling and post-filling events ( r2> 0.9, root mean square error < 0.3 dB, standard error <0.01 dB, and P < 0.001). SHAPE showed a transient behavior in measuring bladder phantom pressure. The SHAPE conversion factor (in dB/cm H 2 O) varied between filling and post-filling events, as well as by post-filling time. The magnitude of the SHAPE conversion factor tended to increase immediately after filling and then decreases with time. Microbubble subharmonic emission is an excellent indicator of bladder phantom pressure variation. The strong correlation between SHAPE signal and bladder phantom pressure is indicative of the applicability of this method in measuring bladder pressure during a CMG. Our results suggest that different SHAPE conversion factors may be needed for different events during a CMG (ie, at different time points of a CMG). These findings will help us better protocolize this method for introduction into human subjects and allow us to take the next step toward developing a catheter-free voiding CMG using SHAPE.

Home bladder pressure measurements correlate with urodynamic storage pressures and high-grade hydronephrosis in children with spina bifida

Patients with spina bifida are at risk for developing bladder and renal deterioration secondary to increased bladder storage pressures. To determine the association of home bladder volume and pressure measurements (home manometry) to: 1) detrusor storage pressures on urodynamics (UDS); and 2) the presence of Society of Fetal Urology (SFU) grades 3-4 hydronephrosis on renal bladder ultrasound in patients with spina bifida. Data were prospectively collected on patients with spina bifida and neurogenic bladder requiring clean intermittent catheterization. Patients used a ruler and typical catheterization equipment to measure bladder pressures and volumes at home. Home measurements were compared to UDS detrusor pressures and SFU hydronephrosis grade. Detrusor pressure <20cmH2O at 50% maximal cystometric capacity (MCC) on UDS was used as a measure of safe storage pressures on UDS; conversely, detrusor pressure >20cmH2O was used a measure to capture both unsafe storage pressures and those with potential for unsafe storage pressures. Receiver-operator characteristic curves and area under curve (AUC) were calculated to depict the association between home manometry variables with detrusor pressures on UDS and SFU grades 3-4 hydronephrosis. Included were 52 patients with a median age of 10.3 years (interquartile range 6.3-14.4 years). Three home manometry measurements (maximum bladder pressure, bladder pressure at maximum catheterized volume, and mean bladder pressure)>20cmH2O were sensitive for Pdet >20cmH2O at 50% MCC. Maximal bladder pressure >20cmH2O was the most sensitive among home manometry measures (sensitivity 100%, specificity 70%, AUC 0.92 for Pdet >20cmH2O at 50% MCC on UDS; sensitivity 100%, specificity 62%, AUC 0.89 for SFU grade 3-4 hydronephrosis). None of the patients who had maximum home bladder pressure <20cmH2O had SFU grades 3-4 hydronephrosis; conversely, individuals with maximal home bladder pressure >20cm had a wide range of hydronephrosis grades. None of the patients with maximal home bladder pressure <20cmH2O had grade 3-4 hydronephrosis. Home measurements of maximal bladder pressure, bladder pressure at maximum catheterized volume and mean bladder pressure of >20cmH2O were all sensitive for Pdet >20cmH2O at 50% MCC on UDS. Home manometry is an inexpensive and simple technique to identify patients at risk for and to monitor individuals at high risk of upper tract dilation, without incurring significant cost or morbidity.

Intra-abdominal hypertension in cardiac surgery patients: a multicenter observational sub-study of the Accuryn registry

Intra-abdominal hypertension (IAH) is frequently present in the critically ill and is associated with increased morbidity and mortality. Conventionally, intermittent ‘spot-check’ manual measurements of bladder pressure in those perceived as high risk are used as surrogates for intra-abdominal pressure (IAP). True patterns of IAH remain unknown. We explored the incidence of IAH in cardiac surgery patients and describe the intra-and postoperative course of IAP using a novel, high frequency, automated bladder pressure measurement system. Sub-analysis of a prospective, multicenter, observational study (NCT04669548) conducted in three large academic medical centers. Continuous urinary output (CUO) and IAP measurements were observed using the Accuryn Monitoring System (Potrero Medical, Hayward, CA). Data collected included demographics, hemodynamic support, and high-frequency IAP and CUO. One Hundred Thirty-Seven cardiac surgery patients were analyzed intraoperatively and followed 48 h postoperatively in the intensive care unit. Median age was 66.4 [58.3, 72.0] years, and 61% were men. Median Foley catheter dwell time was 56.0 [46.8, 77.5] hours, and median baseline IAP was 6.3 [4.0, 8.1] mmHg. 93% (128/137) of patients were in IAH grade I, 82% (113/137) in grade II, 39% (53/137) in grade III, and 5% (7/137) in grade IV for at least 12 cumulative hours. For maximum consecutive duration of IAH, 84% (115/137) of patients spent at least 12 h in grade I, 62% (85/137) in grade II, 18% (25/137) in grade III, and 2% (3/137) in grade IV IAH. During the first 48 h after cardiac surgery, IAH is common and persistent. Improved and automated monitoring of IAP will increase the detection of IAH—which normally would remain undetected using traditional intermittent monitoring methods.

MP29-18 POST-OPERATIVE BLADDER PRESSURE MONITORING FOR SAME DAY CATHETER REMOVAL AFTER HOLEP

You have accessJournal of UrologyCME1 May 2022MP29-18 POST-OPERATIVE BLADDER PRESSURE MONITORING FOR SAME DAY CATHETER REMOVAL AFTER HOLEP Gopal Narang, Charlotte Pougnier, Lanyu Mi, Kevin Wymer, Mitchell Humphreys, and Scott Cheney Gopal NarangGopal Narang More articles by this author , Charlotte PougnierCharlotte Pougnier More articles by this author , Lanyu MiLanyu Mi More articles by this author , Kevin WymerKevin Wymer More articles by this author , Mitchell HumphreysMitchell Humphreys More articles by this author , and Scott CheneyScott Cheney More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002572.18AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Early catheter removal represents a potential opportunity to improve quality of life and limit treatment burden for patients undergoing BPH procedures. It has proven feasible in patients undergoing HoLEP but only under strict criteria. Furthermore, the influence of patient factors, such as post-operative bladder function, on early catheter removal has not been studied. To help address these limitations, we sought to determine if same day catheter removal was feasible in a generalizable population of HoLEP patients and if bladder pressure assessment could improve success rates. METHODS: From February 2021 to August 2021, we prospectively evaluated same day catheter removal for patients undergoing HoLEP. Patients were excluded if they had a history of atonic or hypocontractile bladder. All patients were anesthetized with general anesthesia and paralyzed. Criteria for proceeding with same day catheter removal included: an uncomplicated procedure, continuous bladder irrigation weaned within 120 minutes of arrival to PACU, minimal hematuria rated with a standardized scale and a bladder pressure over 30 cmH20 as measured using the VP TestTM device (SRS Medical). RESULTS: Over a 6-month period, 45 patients were enrolled in our study. The median age was 68 (IQR: 63.0-72.0) and prostate volume 79.1cc (IQR: 61.0-103.5). Criteria for catheter removal was met by 35 patients; 9 patients were unable to meet bladder pressure cutoffs and 1 was excluded for hematuria. Of those that attempted a trial of void, 29/35 passed for an effective pass rate of 83%. For those that failed trial of void, 100% had uncomplicated catheter replacement in PACU with a median catheter duration of 2 days (IQR: 1-3). Median maximum detrusor pressure for those that passed, failed, and did not attempt a trail of void were 55.0 cmH20 (IQR: 43.0-84.0), 46.0 cmH20 (IQR: 35.0-61.0) and 13.0 cmH20 (IQR: 8.0-23.0), respectively. CONCLUSIONS: In a population of patients who received general anesthesia and paralysis for HoLEP, same day catheter removal is feasible. There are differences in measured post-operative bladder pressure between those that passed and failed trial of void. Bladder pressure measurements in the post-operative setting may be a helpful adjunct for those considering same day catheter removal in HoLEP patients. Source of Funding: SRS medical supplied devices free of charge © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e476 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Gopal Narang More articles by this author Charlotte Pougnier More articles by this author Lanyu Mi More articles by this author Kevin Wymer More articles by this author Mitchell Humphreys More articles by this author Scott Cheney More articles by this author Expand All Advertisement PDF DownloadLoading ...

Elevated intra-abdominal pressure: A review of current knowledge.

Elevated intra-abdominal pressure (IAP) is a known cause of increased morbidity and mortality among critically ill patients. Intra-abdominal hypertension (IAH) and abdominal compartment syndrome can lead to rapid deterioration of organ function and the development of multiple organ failure. Raised IAP affects every system and main organ in the human body. Even marginally sustained IAH results in malperfusion and may disrupt the process of recovery. Yet, despite being so common, this potentially lethal condition often goes unnoticed. In 2004, the World Society of the Abdominal Compartment Syndrome, an international multidisciplinary consensus group, was formed to provide unified definitions, improve understanding and promote research in this field. Simple, reliable and nearly costless standardized methods of non-invasive measurement and monitoring of bladder pressure allow early recognition of IAH and timely optimized management. The correct, structured approach to treatment can have a striking effect and fully restore homeostasis. In recent years, significant progress has been made in this area with the contribution of surgeons, internal medicine specialists and anesthesiologists. Our review focuses on recent advances in order to present the complex underlying pathophysiology and guidelines concerning diagnosis, monitoring and treatment of this life-threatening condition.

Superficial peroneal neuromodulation of nonobstructive urinary retention induced by prolonged pudendal afferent activity in cats.

The purpose of this study is to determine whether superficial peroneal nerve stimulation (SPNS) can improve nonobstructive urinary retention (NOUR) induced by prolonged pudendal nerve stimulation (PNS). In this exploratory acute study using eight cats under anesthesia, PNS and SPNS were applied by nerve cuff electrodes. Skin surface electrodes were also used for SPNS. A double lumen catheter was inserted via the bladder dome for bladder infusion and pressure measurement and to allow voiding without a physical urethral outlet obstruction. The voided and postvoid residual (PVR) volumes were also recorded. NOUR induced by repetitive (4-13 times) application of 30-min PNS significantly (P < 0.05) reduced voiding efficiency by 49.5 ± 16.8% of control (78.3 ± 7.9%), with a large PVR volume at 208.2 ± 82.6% of control bladder capacity. SPNS (1 Hz, 0.2 ms) at 1.5-2 times threshold intensity (T) for inducing posterior thigh muscle contractions was applied either continuously (SPNSc) or intermittently (SPNSi) during cystometrograms to improve the PNS-induced NOUR. SPNSc and SPNSi applied by nerve cuff electrodes significantly (P < 0.05) increased voiding efficiency to 74.5 ± 18.9% and 67.0 ± 15.3%, respectively, and reduced PVR volume to 54.5 ± 39.0% and 88.3 ± 56.0%, respectively. SPNSc and SPNSi applied noninvasively by skin surface electrodes also improved NOUR similar to the stimulation applied by a cuff electrode. This study indicates that abnormal pudendal afferent activity could be a pathophysiological cause for the NOUR occurring in Fowler's syndrome and a noninvasive superficial peroneal neuromodulation therapy might be developed to treat NOUR in patients with Fowler's syndrome.

Fatal Abdominal Compartment Syndrome Due to Constipation: A Case Report.

IntroductionAbdominal compartment syndrome (ACS) is a rare condition in which increased intra-abdominal pressure causes multiorgan dysfunction through decreased perfusion. Causes of this condition are variable, and early recognition is critical for favorable patient outcomes. Measurement of bladder pressure is recommended for diagnosis.Case ReportA 64-year-old female on clozapine with a two-year history of chronic constipation presented to the emergency department in extremis with a protuberant abdomen. After resuscitative measures, computed tomography showed a dilated, stool-filled colon with a decompressed inferior vena cava and decreased perfusion. She died despite surgical decompression.ConclusionSevere constipation is a rare cause of ACS, and there is a lack of evidence-based guidelines. Options for bedside decompression are limited. To reduce morbidity and mortality in this population, early recognition of ACS is imperative. Initial interventions should support hemodynamics and respiration. Definitive management is surgical decompression.

Serial transurethral cystometry: A novel method for longitudinal evaluation of reflex lower urinary tract function in adult female rats.

AimsThe aim of the study is to develop a minimally invasive method for longitudinal evaluation of lower urinary tract function that allows for simultaneous measurements of bladder pressure and external urethral sphincter (EUS) electromyographic (EMG) activity.MethodsTo evaluate the reliability of serial transurethral cystometry (STUC), rats (n = 12) underwent three sessions of STUC, one session a week for 3 weeks. During each session, rats were anesthetized with ketamine–xylazine (90 mg/kg and 10 mg/kg), and micturition reflex data were acquired using transurethral cystometry and percutaneous recording of EUS (EMG) activity during continuous infusion of saline into the bladder. The reliability and consistency of the STUC method were assessed using intra‐class correlation (ICC) analysis and repeated measures ANOVA.ResultsICC values calculated from five successive events during the first micturition session indicate good to excellent reliability for measurements of peak bladder pressure, threshold bladder pressure, minimum bladder pressure, volume threshold, duration of EUS bursting, and number of EUS burst events. Across the three recording sessions no significant difference was observed in peak bladder pressure, threshold bladder pressure, minimum bladder pressure, volume threshold, number of EUS burst events, and duration of EUS bursting using repeated measures ANOVA.ConclusionSerial transurethral cystometry under ketamine–xylazine anesthesia with simultaneous percutaneous EUS EMG recording is a novel, reliable, accurate, and minimally invasive method for quantitative assessment of lower urinary tract (LUT) function in adult female rats over extended periods of time.