Intravesical Pressure Measurement Research Articles

Abdominal compartment syndrome: what radiologist needs to know.

The intra-abdominal hypertension (IAH) and the abdominal compartment syndrome (ACS) are life-threatening conditions with a significant rate of mortality; therefore, early detection is paramount in their optimal management. IAH is diagnosed when the intra-abdominal pressure (IAP) is more than 12mmHg. It can occur when the intra-abdominal volume increases (ileus, ascites, trauma, pancreatitis, etc.) and/or the abdominal wall compliance decreases. IAH can cause decreased venous flow, low cardiac output, renal impairment, and decreased respiratory compliance. Consequently, these complications can lead to multiple organ failure and induce the abdominal compartment syndrome (ACS) when IAP rises above 20mmHg. The diagnosis is usually made with intravesical pressure measurement. However, this measurement was not always possible to obtain; therefore, alternative diagnostic techniques should be considered. In this setting, computed tomography (CT) may play a crucial role, allowing the detection and characterization of pathological conditions that may lead to IAH. This review is focused on the pathogenesis, clinical features, and radiological findings of ACS, because their presence allows radiologists to raise the suspicion of IAH/ACS in critically ill patients, guiding the most appropriate treatment.

Management of spinal cord injury patients with neurogenic lower urinary tract dysfunction using minimally invasive and surgical therapies in Taiwan.

The main problems of neurogenic lower urinary tract dysfunction (NLUTD) in patients with spinal cord injury (SCI) consist of impaired urine storage, impaired bladder emptying, or both. The priorities in the management of SCI-NLUTD should be preservation of renal function, followed by freedom from urinary tract infections and improvement of quality of life. Management of NLUTD in patients with SCI must be based on urodynamic findings rather than clinical evaluations. In the hospital without urodynamic equipment, careful measurement of intravesical pressure and safety functional bladder capacity in conjunction with clinical assessment are also feasible. Identification of high-risk patients is important for preventing urological complications in patients with chronic SCI. The management of NLUTD should start with conservative bladder management and medical treatment. Patients with SCI should be regularly followed up, and any NLUTDs and urological complications should be adequately treated. When surgical intervention is necessary, less invasive and reversible procedures should be considered first, and any unnecessary surgery should be avoided. This article reports the current evidence and expert opinions on the patient-centered bladder management of NLUTD in chronic SCI patients in Taiwan. To avoid renal function deterioration and urological complications, annual active surveillance of bladder and renal function is mandatory, especially for high-risk SCI patients.

The association between maternal intra-abdominal pressure and hypertension in pregnancy.

Pregnancy leads to a state of chronically increased intra-abdominal pressure (IAP) caused by a growing fetus, fluid, and tissue. Increased intra-abdominal pressure is leading to state of Intra-Abdominal Hypertension (IAH) and Abdominal Compartment Syndrome. Clinical features and risk factors of preeclampsia is comparable to abdominal compartment syndrome. IAP may be associated with the hypertension in pregnancy (HIP). The study aimed to determine the antepartum and postpartum IAP levels in women undergoing caesarean delivery (CD) and association between hypertension in pregnancy, and antepartum and postpartum IAP levels in women undergoing CD. Seventy pregnant women (55 normotensive, 15 HIP) undergoing antepartum, non-emergency CD, had their intravesical pressure measured before and after the CD, the intravesical pressure measurements obtained with the patient in the supine position were considered to correspond to the IAP. Multivariable linear regression models were used to study associations between intraabdominal pressure and baseline characteristics in normotensive pregnancies and hypertensive pregnancies. In normotensive pregnancies at mean gestation age of 38.2 weeks (95%CI 37.9 to 38.6), mean antepartum IAP was 12.7 mmHg(95%CI 11.6 to 13.8) and the mean postpartum IAP was 7.3 mmHg (95% CI 11.6 to 13.8). Multivariable linear regression models showed HIP group antepartum IAP positively associated with coefficient value of 1.617 (p = 0.268) comparing with normotensive pregnancy group. Postpartum IAP in HIP group positively associated with coefficient value of 2.519 (p = 0.018) comparing with normotensive pregnancy group. IAP difference is negatively associated with HIP (coefficient -1.013, p = 0.179). In normotensive pregnancies at term, the IAP was in the IAH range of the non-pregnant population. Higher Antepartum IAP and Postpartum IAP are associated with HIP. Reduction of IAP from antepartum period to postpartum period was less with HIP.

GABAergic and glutamatergic transmission reveals novel cardiovascular and urinary bladder control features in the shell nucleus accumbens

The shell Nucleus Accumbens (NAcc) projects to the lateral preoptic area, which is involved in the central micturition control and receives inputs from medullary areas involved in cardiovascular control. We investigated the role of GABAergic and glutamatergic transmission in the shell NAcc on intravesical pressure (IP) and cardiovascular control. Male Wistar rats with guide cannulas implanted bilaterally in the shell NAcc 7 days prior to the experiments were anesthetized with 2% isoflurane in 100% O2 and subjected to cannulation of the femoral artery and vein for mean arterial pressure (MAP) and heart rate recordings (HR) and infusion of drugs, respectively. The urinary bladder (UB) was cannulated for IP measurement. A Doppler flow probe was placed around the renal arterial for renal blood flow (RBF) measurement. After the baseline MAP, HR, IP and RBF recordings for 15 min, GABA or bicuculline methiodate (BMI) or L-glutamate or kynurenic acid (KYN) or saline (vehicle) were bilaterally injected into the shell NAcc and the variables were measured for 30 min. Data are as mean ± SEM and submitted to Student́s t test. GABA injections into the shell NAcc evoked a significant fall in MAP and HR and increased IP and RC compared to saline. L-glutamate in the shell NAcc increased MAP, HR and IP and reduced RC. Injections of BMI and KYN elicited no changes in the variables recorded. Therefore, the GABAergic and glutamatergic transmissions in neurons in the shell NAcc are involved in the neural pathways responsible for the central cardiovascular control and UB regulation.

The accuracy of the new non-invasive intra-abdominal pressure measurement by physical examination and ultrasound to diagnose intra-abdominal hypertension: The research protocol

Background: Twenty-five percent of critically ill patients in the intensive care unit have intra-abdominal hypertension, which causes high morbidity and mortality. The gold standard non-invasive method for measuring intra-abdominal pressure to diagnose intra-abdominal hypertension is intravesical pressure measurement. Unfortunately, the standard method has several limitations. The aim of this study is to invent a new, non-invasive method to diagnose intra-abdominal hypertension. Methods: This is a cross-sectional study to determine the accuracy of the new non-invasive intra-abdominal pressure measurement by physical examination and ultrasound to diagnose intra-abdominal hypertension compared to the intravesical pressure measurement. Hypothesis: We hypothesize that physical examination and ultrasound can be used to diagnose intra-abdominal hypertension and the ratio of maximal anteroposterior to transverse abdominal diameter minus fat thickness and intra-abdominal pressure has a correlation. Ethics and dissemination: The study received ethical approval from the Institutional Review Board of Faculty of Medicine, Chulalongkorn University. We plan to disseminate the results in peer-reviewed journals related to critical care medicine or surgery and at national or international conferences.

Alteration in Mechanical Compliance via Mast Cell Activation in Juvenile and Adult Urinary Bladder

Balance between bladder wall stiffness and mechanical compliance is essential to maintain normal bladder function. These biomechanical properties are directly influenced by the integrity of the extracellular matrix (ECM) and its interaction with urinary bladder smooth muscle (UBSM). While it is clear that normal storage and voiding functions differ between juveniles and adults, it is unclear if these differences are due solely to increases in bladder size. Differences in the mechanical properties of the wall may also exist and are unexplored. Changes in mechanical compliance are implicated in the pathophysiology of many lower urinary tract symptoms (LUTS) such as overactivity and fibrosis due to inflammation. Interestingly, juvenile bladders are particularly susceptible to inflammatory LUTS by various factors (e.g., early life stress) compared to their adult counterparts. We were interested in how bladders from juvenile and adult mice respond to inflammation, specifically driven by mast cell degranulation. We hypothesized that: (1) juvenile bladders are inherently more compliant than adult bladders and (2) mast cell degranulation increases mechanical compliance in both juvenile and adult mouse bladders.Whole mouse bladders from juvenile (4–5 weeks old) and adult (12–14 weeks old) C57Bl/6 male mice were dissected and mounted in a custom designed pentaplanar reflected image macroscopy (PRIM) system for simultaneous measurement of transient pressure events, intravesical pressure, bladder volume, wall stress, and wall stretch during ex vivo bladder filling. Mechanical properties of the bladder wall were measured as the relationship between mechanical stress versus stretch. Properties of the transient contractions were calculated using acquired pressure-volume curves. Measurements were performed in the absence or presence of the mast cell activator Compound 48/80 (10 μg/mL).In the absence of Compound 48/80, the average stress-stretch curves had no significant shift for adult mice compared to young mice, implying no changes in mechanical compliance. However, the mechanical stress in adult mouse bladders was higher compared to juvenile bladders, implying that adult bladders were stiffer. In presence of Compound 48/80, both age groups show similar effects. Mechanical compliance increased with a paradoxical increase in amplitude of transient contractions. Together, these data suggest that while juvenile mouse bladders are less stiff, they respond to mast cell activation in a similar manner as adult bladders. Consequently, rapid degranulation of mast cells in juvenile bladders leads to increased mechanical compliance and contractility. Thus, preventing mast cell degranulation could represent a viable target for treating LUTS in children as well as adults. R01-DK119615 (NRT) and P20-DK127554 (SR and NRT) This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

S1894 A Case of Severe Acute Alcoholic Pancreatitis Complicated With Abdominal Compartment Syndrome

Introduction: Abdominal compartment syndrome (ACS) is a sustained intra-abdominal pressure (IAP) above 20mmHg with associated new-onset organ dysfunction. Even though it is rarely seen in clinical practice, up to 15% of patients with severe acute pancreatitis (SAP) develop ACS and have a mortality rate of up to 49%. Given that delayed treatment of ACS is associated with high mortality and adverse outcome, a higher clinical suspicion is needed to aid diagnosis. We present a case of severe pancreatitis complicated with ACS. Case Description/Methods: A 29-year-old man with a history of alcohol abuse presented with five days of severe abdominal pain. He was diagnosed with SAP. About 8 hours into admission to the ICU and resuscitation, he began having worsening work of breathing and persistent severe abdominal pain despite being on adequate opioid analgesic. Physical examination revealed tachycardia, diffuse peritoneal signs, guarding, and shock. Repeat labs revealed worsening leukocytosis, thrombocytopenia, hyperkalemia, hypocalcemia, lactic acidosis, and elevated creatinine kinase. There was also evidence of renal failure. An edematous pancreas with some peripancreatic fluid collection was evident on the CT abdomen (Figure). The abdominal x-ray was unremarkable. Indirect intra-abdominal pressure (IAP) by intravesical catheter pressure measurement was 35mmHg. He commenced medical management with neuromuscular paralysis and mechanical ventilatory support. A repeat IAP was 24mmHg. He then got surgical decompression by full-thickness midline laparotomy with wound vac placement which further reduced the IAP to 10mmHg. He received serial dialysis, correction of abnormal electrolytes, and serial transfusion with blood products as required. He remained critically ill on a mechanical ventilator and vasopressors, with a poor prognosis at the time of this writing. Discussion: The pathophysiology of elevated IAP in SAP is multifactorial. These include retroperitoneal inflammation, ascites, acute peripancreatic fluid collections, visceral edema, and aggressive fluid resuscitation. We believe some of the above listed had ensued in our patient for days before he presented to the hospital. Physical examination is inaccurate in diagnosing ACS. The first-line treatment is medical paralysis followed by surgical decompression if ineffective. We are writing this case to recommend early serial IAP measurements in patients with SAP.Figure 1.: CT abdomen showing edematous pancreas with some peripancreatic fluid collection.

Activation of 5-HT3 receptors in the medulla oblongata is involved in the phasic control of urinary bladder

The control of micturition depends on reflex mechanisms, however, it undergoes modulation from cortex, pons and medullary areas. This study investigated if the activation of 5-HT3 receptors in the medulla influences the urinary bladder (UB) regulation in rats. Isoflurane female Wistar rats were submitted to catheterization of the femoral artery and vein for mean arterial pressure (MAP) and heart rate (HR) recordings and injection of drugs, respectively. The UB was cannulated for intravesical pressure (IP) measurement. The Doppler flow probe was placed around the left renal artery for renal conductance (RC) recordings. Phenylbiguanide (PB) and granisetron (GN) were injected into the 4th brain ventricle in rats with guide cannulas implanted 5 days prior to the experiments; or PB and GN were randomly injected intravenously or applied topically (in situ) on the UB. PB injection into 4th V significantly increased IP (68.67 ± 11.70%) and decreased MAP (−29 ± 6 mmHg) compared to saline (0.34 ± 0.64% and −2 ± 2 mmHg), with no changes in the HR and RC. GN injection into the 4th V did not significantly change the IP and RC compared to saline, nevertheless, significantly increased MAP (25 ± 4 mmHg) and heart rate (36 ± 9 bpm) compared to saline. Intravenous PB and GN only produced cardiovascular effects, whilst PB but not GN in situ on the UB evoked increase in IP (111.60 ± 30.36%). Therefore, the activation of 5HT-3 receptors in medullary areas increases the intravesical pressure and these receptors are involved in the phasic control of UB. In contrast, 5-HT3 receptors in the medulla oblongata are involved in the pathways of the tonic control of the cardiovascular system. The activation of 5-HT3 receptors in the bladder cause increase in intravesical pressure and this regulation seem to be under phasic control as the blockade of such receptors elicits no changes in baseline intravesical pressure.

In Vivo Luminal Measurement of Distension-evoked Urothelial ATP Release in Rodents.

ATP, released from the urothelium in response to bladder distension, is thought to play a significant sensory role in the control of micturition. Therefore, accurate measurement of urothelial ATP release in a physiological setting is an important first step in studying the mechanisms that control purinergic signaling in the urinary bladder. Existing techniques to study mechanically evoked urothelial ATP release utilize cultured cells plated on flexible supports or bladder tissue pinned into Ussing chambers; however, each of these techniques does not fully emulate conditions in the intact bladder. Therefore, an experimental setup was developed to directly measure ATP concentrations in the lumen of the rodent urinary bladder. In this setup, the bladders of anesthetized rodents are perfused through catheters in both the dome of the bladder and via the external urethral orifice. Pressure in the bladder is increased by capping the urethral catheter while perfusing sterile fluid into the bladder through the dome. Measurement of intravesical pressure is achieved using a pressure transducer attached to the bladder dome catheter, akin to the setup used for cystometry. Once the desired pressure is reached, the urethral catheter's cap is removed, and fluid collected for ATP quantification by luciferin-luciferase assay. Through this experimental setup, the mechanisms controlling both mechanical and chemical stimulation of urothelial ATP release can be interrogated by including various agonists or antagonists into the perfusate or by comparing results between wildtype and genetically modified animals.

Machine learning-assisted fluoroscopy of bladder function in awake mice.

Understanding the lower urinary tract (LUT) and development of highly needed novel therapies to treat LUT disorders depends on accurate techniques to monitor LUT (dys)function in preclinical models. We recently developed videocystometry in rodents, which combines intravesical pressure measurements with X-ray-based fluoroscopy of the LUT, allowing the in vivo analysis of the process of urine storage and voiding with unprecedented detail. Videocystometry relies on the precise contrast-based determination of the bladder volume at high temporal resolution, which can readily be achieved in anesthetized or otherwise motion-restricted mice but not in awake and freely moving animals. To overcome this limitation, we developed a machine-learning method, in which we trained a neural network to automatically detect the bladder in fluoroscopic images, allowing the automatic analysis of bladder filling and voiding cycles based on large sets of time-lapse fluoroscopic images (>3 hr at 30 images/s) from behaving mice and in a noninvasive manner. With this approach, we found that urethane, an injectable anesthetic that is commonly used in preclinical urological research, has a profound, dose-dependent effect on urethral relaxation and voiding duration. Moreover, both in awake and in anesthetized mice, the bladder capacity was decreased ~fourfold when cystometry was performed acutely after surgical implantation of a suprapubic catheter. Our findings provide a paradigm for the noninvasive, in vivo monitoring of a hollow organ in behaving animals and pinpoint important limitations of the current gold standard techniques to study the LUT in mice.

Preliminary study of reliability of transcutaneous sensors in measuring intraabdominal pressure

Early recognition of elevated intraabdominal pressure (IAP) in critically ill patients is essential, since it can result in abdominal compartment syndrome, which is a life-threatening condition. The measurement of intravesical pressure is currently considered the gold standard for IAP assessment. Alternative methods have been proposed, where IAP assessment is based on measuring abdominal wall tension, which reflects the pressure in the abdominal cavity. The aim of this study was to evaluate the feasibility of using patch-like transcutaneous sensors to estimate changes in IAP, which could facilitate the monitoring of IAP in clinical practice. This study was performed with 30 patients during early postoperative care. All patients still had an indwelling urinary catheter postoperatively. Four wearable sensors were attached to the outer surface of the abdominal region to detect the changes in abdominal wall tension. Additionally, surface EMG was used to monitor the activity of the abdominal muscles. The thickness of the subcutaneous tissue was measured with ultrasound. Patients performed 4 cycles of the Valsalva manoeuvre, with a resting period in between (the minimal resting period was 30 s, with a prolongation as necessary to ensure that the fluid level in the measuring system had equilibrated). The IAP was estimated with intravesical pressure measurements during all resting periods and all Valsalva manoeuvres, while the sensors continuously measured changes in abdominal wall tension. The association between the subcutaneous thickness and tension changes on the surface and the intraabdominal pressure was statistically significant, but a large part of the variability was explained by individual patient factors. As a consequence, the predictions of IAP using transcutaneous sensors were not biased, but they were quite variable. The specificity of detecting intraabdominal pressure of 20 mmHg and above is 88%, with an NPV of 96%, while its sensitivity and PPV are currently far lower. There are inherent limitations of the chosen preliminary study design that directly caused the low sensitivity of our method as well as the poor agreement with the gold standard method; in spite of that, we have shown that these sensors have the potential to be used to monitor intraabdominal pressure. We are planning a study that would more closely resemble the intended clinical use and expect it to show more consistent results with a far smaller error.

Compound 48/80 increases bladder wall compliance independent of mast cells

Changes in wall compliance are seen in many bladder pathologies, such as fibrosis and diabetes. Some of these pathologies can be caused by basic secretagogues like Compound 48/80 and its endogenous analogue, Substance P. Traditionally it is believed that basic secretagogues rapidly degranulate mast cells and release inflammatory mediators by acting on an orphan receptor, Mas‐related G protein‐coupled receptor B2 (Mrgprb2). While Compound 48/80 does increase wall compliance, the exact location and function of Mrgprb2 in the urinary bladder are still unknown. We hypothesize that changes in bladder wall compliance caused by Compound 48/80 are mediated through Mrgprb2 receptors but independent of mast cell degranulation.Whole mouse bladders from C57Bl/6 (wild‐type) and C‐kitW‐sh (mast cell‐deficient) mice were dissected and mounted in a custom designed pentaplanar reflected image macroscopy (PRIM) system for simultaneous measurement of transient pressure events, intravesical pressure, bladder volume, wall stress, and wall stretch during ex vivo bladder filling. Wall compliance was derived as a measure of the stress versus stretch relationship using the pressure‐volume curves and associated imaging data. To test our hypothesis, bladders were exposed to either vehicle or Compound 48/80 (10 µg/ml) during ex vivo filling. Compound 48/80 significantly increased the leading slope of transient pressure events in both wild‐type and mast cell‐deficient mice. Compliance was also increased, as shown by decreased stress per change in stretch. We also collected urothelium and detrusor layers from C57Bl/6 and C‐kitW‐sh mouse bladders. Layers were separated using blunt dissection, and RNA was isolated for measurement of Mrgprb2 expression using qRT‐PCR. No significant difference in the expression of Mrgprb2 mRNA was observed between the two mouse models in either the urothelium or detrusor layers. These findings suggest that Mrgprb2 receptors are also expressed outside of mast cells in the urinary bladder wall and, when activated by Compound 48/80, increase wall compliance and the leading slope of transient pressure events.

The Sheep as a Comprehensive Animal Model to Investigate Interdependent Physiological Pressure Propagation and Multiparameter Influence on Cerebrospinal Fluid Dynamics.

The present study aims to develop a suitable animal model for evaluating the physiological interactions between cerebrospinal fluid (CSF) dynamics, hemodynamics, and abdominal compartment pressures. We seek to contribute to the enhanced recognition of the pathophysiology of CSF-dependent neurological disorders like hydrocephalus and the improvement of available treatment options. To date, no comprehensive animal model of CSF dynamics exists, and establishing an accurate model will advance our understanding of complex CSF physiology. Persisting knowledge gaps surrounding the communication and pressure propagation between the cerebrospinal space and adjacent anatomical compartments exacerbate the development of novel therapies for neurological diseases. Hence, the need for further investigation of the interactions of vascular, craniospinal, and abdominal pressures remains beyond dispute. Moreover, the results of this animal study support the optimization of in vitro test benches for medical device development, e.g., ventriculoperitoneal shunts. Six female white alpine sheep were surgically equipped with pressure sensors to investigate the physiological values of intracranial, intrathecal, arterial, central venous, jugular venous, vesical pressure, and four differently located abdominal pressures. These values were measured simultaneously during the acute animal trial with sheep under general anesthesia. Both carotid and femoral arterial blood pressure indicate a reliable and comparable representation of the systematic blood pressure. However, the jugular venous pressure and the central venous pressure in sheep in dorsal recumbency do not correlate well under general anesthesia. Furthermore, there is a trend for possible comparability of lateral intraventricular and lumbar intrathecal pressure. Nevertheless, animal body position during measurements must be considered since different body constitutions can alter the horizontal line between the cerebral ventricles and the lumbar subarachnoid space. While intra-abdominal pressure measurement in the four different abdominal quadrants yielded greater inter-individual variability, intra-vesical pressure measurements in our setting delivered comparable values for all sheep. We established a novel and comprehensive ovine animal model to investigate interdependent physiologic pressure propagation and multiparameter influences on CSF dynamics. The results of this study will contribute to further in vitro bench testing, the derivation of novel quantitative models, and the development of a pathologic ovine hydrocephalus model.

Daily acute intermittent hypoxia therapy 1‐week after moderate contusion spinal cord injury improves lower urinary tract function in rats

There is an increasing interest in the use of non-invasive acute intermittent hypoxia (AIH) as a therapeutic intervention to improve respiratory and locomotor function in spinal cord injury (SCI). SCI, however, also significantly disrupts normal bladder function, leading to detrusor overactivity, decreased voiding efficiency, and increased residual volume. Ongoing studies in our laboratory investigating the effects of AIH exposure in rats as a strategy for improving lower urinary tract (LUT) function following mid-thoracic SCI indicate that a single bout of AIH decreases the incidence of non-voiding bladder contractions (NVCs) and increases voiding efficiency. In the current study, we begin to evaluate the potential for AIH to be used as a therapy for inducing long-lasting improvements in SCI-induced LUT dysfunction. To accomplish this, we examined the effects of daily AIH (dAIH) administered for 7 consecutive days on both spontaneous awake micturition patterns and reflex micturition event (rME) behaviors in adult female Sprague-Dawley rats with mid-thoracic moderate contusion (200 kdyn) SCI. For these experiments, dAIH composed of five alternating 3-min exposures of hypoxia (12% O2) and normoxia (21% O2) was initiated 1-week after SCI, with awake micturition patterns being evaluated by overnight metabolic chamber measurements weekly for 2-3-weeks before and 4 weeks after SCI and rME behaviors elicited by continuous infusion of saline (0.04-0.09 ml/min) into the bladder being evaluated by cystometry at 4-weeks after SCI; daily normoxia (dNx; 21% O2 episodes) served as a control. The impact of SCI on hindlimb motor and LUT function prior to initiating dAIH or dNx treatment was evaluated using BBB scores and manually expressed urine volumes during post-operative care, and these measurements revealed that deficits and initial stages of recovery were similar (as expected) in both treatment groups. Serial metabolic chamber measurements in both dAIH- and dNx-treated rats that exhibited functional voids at 1-week post-SCI demonstrated that most rats exhibited some degree of functional recovery of micturition pattern behaviors. Only dAIH-treated rats, however, exhibited a recovery of void frequency pattern (i.e., number of voids and inter-void interval)to pre-SCI levels albeit with slightly increased void volumes; dNx-treated rats also had increased void volumes. Intravesical bladder pressure (BP) measurements during terminal cystometry experiments in urethane-anesthetized (1.4 g/kg) rats revealed that dAIH-treated rats exhibited a decreased incidence of NVCs and that voiding contractions had increased delta BP (peak BP-minimum BP) and dynamic voiding efficiency (void volume/fill volume) compared to dNx-treated rats. Taken together, these findings suggest that dAIH treatment produces beneficial improvements in LUT function lasting at least two weeks that include more efficient voiding and decreased NVCs, and further support the use of dAIH therapy to treat SCI-induced LUT dysfunction.

A New Device for Measuring Abdominal Wall Tension and Its Value in Screening Abdominal Infection.

ObjectiveThis study is the largest clinical study of noninvasive Abdominal wall tension (AWT) measurement with a tensiometer to date. It also initially applies a polynomial regression equation to analyze the correlation between AWT measurement and intravesical pressure (IVP) measurement and remarkably finds interesting changes between different IVP intervals and AWT.MethodsCritically ill patients who were treated in the intensive care unit (ICU) of Daping Hospital, Army Medical University, from August 30, 2018, to June 30, 2020, and met the inclusion criteria were prospectively included in this study. The patients were divided into an intra-abdominal hypertension group and a non-intra-abdominal hypertension group and an abdominal infection group and no abdominal infection group. AWT and IVP were measured at 9 points on the abdominal wall on the first day after admission to the ICU. The correlations between AWTs and IVP were analyzed, and the role of AWT in the diagnosis of complications of abdominal infection and the prediction of adverse prognosis were analyzed.ResultsA total of 127 patients were included. The average AWT and IVP were 2.77±0.38 N/mm and 12.31±7.01 mmHg, respectively, on the first day of admission. There was a positive correlation between AWT and IVP (correlation coefficient r = 0.706, p < 0.05). The polynomial regression model was AWT= -1.616×10−3 IVP2 +8.323×10−2 IVP+2.094. The cutoff value of the sensitivity and specificity of AWT for the diagnosis of abdominal infection was 2.57 N/mm. Furthermore, AWT = 2.57 N/mm had the best diagnostic efficiency, which was better than that of IAH and lactate.ConclusionThere was a correlation between AWT and IVP. AWT measurement was helpful in the diagnosis of IAH and abdominal infection complications and can therefore serve as a new method for the clinical diagnosis of IVP and abdominal infection.

Severe Intraabdominal Hypertension in Critically Ill COVID-19 Patients With Acute Kidney Injury

Severe Intraabdominal Hypertension in Critically Ill COVID-19 Patients With Acute Kidney Injury

A Study of Intra-abdominal Pressure Measurement Using a New Innovative Technique with Foley's Catheter

Aim: We aimed to study intra-abdominal pressure (IAP) measurement using a new innovative technique with Foley's catheter. Introduction: Intra-abdominal hypertension (IAH) is defined as an IAP equal to or above 12 mmHg (16.31 cm of water) (1 mmHg = 1.3 cm of water) and abdominal compartment syndrome (ACS) is defined as an IAP above 20 mmHg along with organ malfunction. Effect of increased intra-abdominal tension is acute renal failure, pulmonary dysfunction, and decreased blood flow to the gastrointestinal organs. It may cause diaphragm elevation along with an increase in intrathoracic pressure causing pulmonary dysfunction and a decrease in the venous return to the brain leading to intracranial congestion and brain dysfunction. Increased IAP is commonly measured by recording intravesical pressure. In this study, we are using 50 ml of saline for urinary bladder pressure measurement through Foley's catheter. Methods: In this prospective study, we measured IAP by Foley's catheter in the urinary bladder in 250 patients which were admitted to our hospital. In this study, 196 patients were male and 54 patients were female. After establishing normal values in routine patients, the IAP was derived above which the values were considered as IAH. Results: Patients with laparoscopic abdominal surgeries, for example, laparoscopic appendectomy and/or laparoscopic cholecystectomy, obstructed hernia (enterocele) and intestinal obstruction, pancreatic ascites, pneumothorax, alcoholic liver disease with ascites, and chronic obstructive pulmonary disease, had raised IAP as compared to others. The average IAP of our patients who were routine patients was 7–9 cm of water. IAH was considered when values were above 9 cm of water. Conclusion: Our study showed that intravesical pressure measurement is a simple, minimally invasive method that may reliably estimate IAP in patients placed in supine position. When applied clinically, this should alert the clinician to take safety measures to avoid ACS.

ULTRASOUND SIGNS OF GALLBLADDER IN PATIENTS WITH ACUTE CHOLECYSTITIS AND BILIARY TRACT OBSTRUCTION IN CASES OF ARTERIO-VENOUS BLOOD FLOW VIZUALIZATION IN ITS WALL

B-mode ultrasound features of the gallbladder changes and Doppler-parameters of increased blood flow in the gallbladder wall as a type of arterial or venous hyperemia are considered the generally recognized signs of acute cholecystitis. However, we did not find information about the influence of intravesical pressure on the cystic artery blood flow, as any date of presence or absence of connection between B-mode gallbladder signs and the degree of venous blood flow change in the gallbladder wall in patients with acute calculous cholecystitis and bile duct obstruction, accompanied by intravesical hypertension. The aim of the study was to identify B-mode ultrasound signs of the gallbladder (GB), in which veins are registered in its wall along with the arteries. This type of blood flow is classified as a venous-arterial type. The venous-arterial blood flow was identified by color duplex scanning in 34 observed people (23,6%) out of 144 patients with acute calculous cholecystitis. While in case of non-inflammatory bile duct obstruction, veins in the GB wall were visualized in 1,9 times more often and were detected in 20 out of 44 (45,5%) patients. Comparing each group with patients who had only an arterial type of blood flow, we obtained the following results: the largest values of the length, area and volume of the gallbladder were identified in patients with recording veins in GB wall, which differed them with a high degree of reliability (p<0,05) from patients with only arterial type of blood flow. Intraoperative intravesical pressure measurement was conducted to all patients. The level of pressure was also significantly higher in patients with venous-arterial blood flow in GB and shows 26,1±2,6 mm water column to compare with 18,0±3,2 mm water column in patients with acute calculous cholecystitis when only arterial blood flow was registered in the GB wall (increase 31,1%); In case of bile duct obstruction the values were 29,0±1,8 mm water column and 25,7±1,6 mm water column respectively. The obtained data shows significance of the intravesical pressure level to the detection of venous blood flow in GB wall by Color Duplex method. The probability of recording venous blood flow in the GB wall in patients with acute calculous cholecystitis and with bile duct obstruction grows with the increase in the length, area and volume of GB to the maximum values.

Angiotensin 1–7 Action in the Lateral Preoptic Area is Involved in Urinary Bladder Regulation in Female Wistar Rats.

BackgroundChemical lesions of the lateral preoptic area (LPA) enhance water intake induced by subcutaneous injection of hypertonic saline in rats. On the other hand, the LPA section abolishes the increase in intravesical pressure (IP) induced by olfactory tubercle stimulation in dogs. Immunohistochemical labeling has demonstrated the presence of Mas receptors for Angiotensin‐(1–7) in LPA. It is not known whether neurons with Mas receptors in LPA are involved in urinary bladder regulation.AimWe investigated the effects of activation or blockade of Mas receptors for angiotensin‐(1–7) in LPA on intravesical pressure in anesthetized female rats.Materials and methodsFemale Wistar rats (~240 g, N=6) underwent to a stereotaxic surgery for implantation of stainless steel guide cannulas into the LPA under ketamine and xylazin anesthesia. After 7 days, the animals were anesthetized and maintained with 2% isoflurane in 100% O2 and submitted to cannulation of the femoral artery and vein, placement of a miniaturized Doppler flow probe around the left renal artery to measure the renal blood flow and cannulation of the urinary bladder for IP measurements. After baseline IP and cardiovascular parameters recordings for 15 min, angiotensin‐(1–7) (5 nmol/ uL) or saline (1 uL) or A‐779 (Mas receptor antagonist, 50 nmol/uL) was injected into the LPA and the variables were measured for additional 60 min.ResultsUnilateral injection of angiotensin‐(1–7) into LPA evoked a significant increase in IP (187.5±37.2%) compared to saline (−2.1±1.9%). Unilateral injection of A‐779 into LPA decreased the IP (−15.9±2.8%) in comparison to saline (2.0±1.1%). Interestingly, the decrease in IP was enhanced after bilateral injection of A‐779 into LPA (−27.3±3.4%) compared to the unilateral injection of this drug and also in comparison to saline (−2.9±1.6%) bilaterally into LPA. No significant changes in cardiovascular parameters after angiotensin‐(1–7) or saline or A‐779 in APL were observed.ConclusionThe data suggest that LPA is an important part of the circuit that regulates the urinary bladder activity mediated by angiotensin‐(1–7).Support or Funding InformationFinancial support: FAPESP and NEPAS‐FMABCThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

A counterforce to diversion of cerebrospinal fluid during ventriculoperitoneal shunting: the intraperitoneal pressure. An observational study.

Intraperitoneal pressure (IPP) counteracts the diversion of cerebrospinal fluid (CSF) from the cranial to the peritoneal compartment during ventriculoperitoneal shunting. Animal studies suggest that the intrinsic IPP exceeds the intraperitoneal hydrostatic pressure. The intrinsic IPP in mobile patients is relevant for shunt therapy, but data about it is not available. The IPP was measured indirectly in 25 mobile subjects (13 female) by applying a standard intravesical pressure measurement technique. Measurements were carried out in reference to the navel (supine position) and the xiphoid (upright position). Results were adjusted for the intraperitoneal hydrostatic pressure and correlated afterward with general body measures. The corrected mean (SD) IPP measured in the supine position was 4.4 (4.5) cm H2O, and the mean (SD) upright IPP was 1.6 (7.8) cm H2O (p= 0.02). A positive correlation was found between the body mass index (BMI) and the IPP in the upright (r= 0.51) and supine (r= 0.65) body positions, and between the abdominal circumference and the IPP in the supine position (r= 0.63). The intrinsic IPP in mobile subjects exceeds the intraperitoneal hydrostatic pressure. Thus, the intrinsic IPP counteracts the diversion of CSF into the peritoneal compartment. The intrinsic IPP is correlated with mobile patients' general body measures.