Changes In Intra-abdominal Pressure Research Articles

An Introduction to Ventra: A Programmable Abdominal Phantom for Training, Educational, Research, and Development Purposes.

Intra-abdominal pressure (IAP) is a critical parameter in the care of critically ill patients, as elevated IAP can lead to reduced cardiac output and organ perfusion, potentially resulting in multiple organ dysfunction and failure. The current gold standard for measuring IAP is an indirect technique via the bladder. According to the Abdominal Compartment Society's Guidelines, new measurement methods/devices for IAP must be validated against the gold standard. This study introduces Ventra, an abdominal phantom designed to simulate different IAP levels, abdominal compliance, respiration-related IAP variations, and bladder dynamics. Ventra aims to facilitate the development and validation of new IAP measurement devices while reducing reliance on animal and cadaveric studies. Additionally, it offers potential applications in training and education for biomedical engineering students. This study provides a thorough explanation on the phantom's design and fabrication, which provides a low-cost solution for advancing IAP measurement research and education. The design concept, technical aspects, and a series of validation experiments determining whether Ventra is a suitable tool for future research are presented in this study. Ventra's performance was evaluated through a series of validation tests using a pressure gauge and two intra-gastric (Spiegelberg and CiMON) and two intra-bladder (Accuryn and TraumaGuard) pressure measurement devices. The mean and standard deviation of IAP recordings by each device were investigated. Bland-Altman analysis was used to evaluate bias, precision, limits of agreement, and percentage error for each system. Concordance analysis was performed to assess the ability of Ventra in tracking IAP changes. The phantom demonstrated excellent agreement with reference pressure measurements, showing an average bias of 0.11 ± 0.49 mmHg. A concordance coefficient of 100% was observed for the phantom as well. Ventra accurately simulated different abdominal compliances, with higher IAP values resulting in lower compliance. Abdominal volume changes showed a bias of 0.08 ± 0.07 L/min, and bladder fill volume measurements showed an average difference of 0.90 ± 4.33 mL for volumes ranging from 50 to 500 mL. The validation results were in agreement with the research guidelines of the world abdominal society. Ventra is a reliable tool that will facilitate the development and validation of new IAP measurement devices. It is an effective educational tool for biomedical engineering students as well.

Comparative evaluation of single versus double leg raise maneuver in high-resolution esophageal manometry.

The straight leg raise (SLR) maneuver, often performed during esophageal manometry, requires patients to lift their leg(s) to augment intraabdominal pressure (IAP). Diverse techniques have been applied for SLR. This study aimed to evaluate and compare the effects of SLR between single and double leg raises. During esophageal manometry, patients were asked to raise one leg, followed by elevating both legs. The efficacy of SLR for (1) detecting hiatal hernia, (2) increasing IAP, and (3) predicting gastroesophageal reflux disease (GERD) with intraesophageal pressure (IEP) was assessed. The value of change in impedance to indicate reflux during SLR in predicting esophageal acid exposure was investigated. The leg raise procedures were performed in 86 patients undergoing high-resolution esophageal manometry. Both the single and double leg raises exhibited a higher hiatal hernia detection rate compared to the landmark (p = 0.008 and 0.005, respectively). Double leg raise was more effective in raising IAP by >50% compared to single leg raise (100% vs. 65.1%, p < 0.001), increasing yield by 53.6%. The change in IAP showed a positive correlation with the change in IEP during double leg raise (r = 0.31; p = 0.004), higher than that for single leg raise (r = 0.23; p = 0.03). Lower intraesophageal impedance during SLR was associated with AET > 6% with double leg raise (1.5 kΩ vs. 2.5 kΩ, p = 0.04). Our study demonstrates the efficacy of both single and double leg raise maneuvers during HREMI in increasing hiatal hernia detection and possible value in predicting GERD. The double leg raise resulted in a higher rate of effective increase in IAP, potentially enabling more patients to undergo effective SLR during HREMI.

Valsalva Retinopathy Induced by Straining Due to Constipation

Valsalva retinopathy is as the rupture of superficial capillaries secondary to an increase in retinal venous pressure, following a sudden change in intrathoracic or intra-abdominal pressure. The Valsalva maneuver is quite common in daily life and typical activities such as coughing hard, vomiting, straining, constipation, and sexual activity can all lead to it. We reported a rare case of multi-level hemorrhages by the Valsalva maneuver in an elderly female with hypertension after heavy straining due to constipation.

Extracranial pressure (ECP) monitoring in severe traumatic brain injury (TBI): A prospective study validating intra-abdominal pressure (IAP) measurement for predicting intracranial pressure (ICP).

Intracranial pressure (ICP)--guided therapy is the standard of care in the management of severe traumatic brain injury (TBI). Ideal ICP monitoring technique is not yet available, based on its risks associated with bleeding, infection, or its unavailability at major centers. Authors propose that ICP can be gauged based on measuring pressures of other anatomical cavities, for example, the abdominal cavity. Researchers explored the possibility of monitoring intra-abdominal pressure (IAP) to predict ICP in severe TBI patients. We measured ICP and IAP in severe TBI patients. ICP was measured using standard right frontal external ventricular drain (EVD) insertion and connecting it to the transducer. IAP was measured using a well-established technique of vesical pressure measurement through a manometer. A total of 28 patients (n = 28) with an age range of 18-65 years (mean of 32.36 years ± 13.52 years [Standard deviation]) and the median age of 28.00 years with an interquartile range (21.00-42.00 years) were recruited in this prospective study. About 57.1% (n = 16) of these patients were in the age range of 18-30 years. About 92.9% (n = 26) of the patients were male. The most common mode of injury (78.6%) was road traffic accidents (n = 22) and the mean Glasgow Coma Scale at presentation was 4.04 (range 3-9). The mean ICP measured at the presentation of this patient cohort was 20.04 mmHg. This mean ICP (mmHg) decreased from a maximum of 20.04 at the 0 h' time point (at the time of insertion of EVD) to a minimum of 12.09 at the 96 hr time point. This change in mean ICP (from 0 h to 96 h) was found to be statistically significant (Friedman Test: χ2 = 87.6, P ≤ 0.001). The mean IAP (cmH2O) decreased from a maximum of 16.71 at the 0 h' time point to a minimum of 9.68 at the 96 h' time point. This change was statistically significant (Friedman Test: χ2 = 71.8, P ≤ 0.001). The per unit percentage change in IAP on per unit percentage change in ICP we observed was correlated to each other. The correlation coefficient between these variables varied from 0.71 to 0.89 at different time frames. It followed a trend in a directly proportional manner and was found to be statistically significant (P < 0.001) in each time frame of the study. The rise in one parameter followed the rise in another parameter and vice versa. In this study, we established that the ICP of severe TBI patients correlates well with IAP at presentation. This correlation was strong and constant, irrespective of the timeframe during the treatment and monitoring. This study also established that draining cerebrospinal fluid to decrease ICP in severe TBI patients is reflected in IAP. The study validates that IAP is a strong proxy of ICP in severe TBI patients.

Full-field in vivo experimental study of the strains of a breathing human abdominal wall with intra-abdominal pressure variation

The presented study aims to assess the mechanical behaviour of the anterior abdominal wall based on an in vivo experiment on humans. Full-field measurement of abdominal wall displacement during changes of intra-abdominal pressure is performed using a digital image correlation (DIC) system. Continuous measurement in time enables the observation of changes in the strain field during breathing. The understanding of the mechanical behaviour of a living human abdominal wall is important for the proper design of surgical meshes used for ventral hernia repair, which was also a motivation for the research presented below.The research refers to the strain field of a loaded abdominal wall and presents the evolution of principal strains and their directions in the case of 12 subjects, 8 male and 4 female. Peritoneal dialysis procedure allows for the measurement of intra-abdominal pressure after fluid introduction.High variability among patients is observed, also in terms of principal strain direction. Subjects exhibit intra-abdominal pressure of values from 11 to 21 cmH2O. However, the strain values are not strongly correlated with the pressure value, indicating variability of material properties.

Abdominal Wall Movements Predict Intra-Abdominal Pressure Changes in Rats: A Novel Non-Invasive Intra-Abdominal Pressure Detection Method.

(1) Background: As increases in intra-abdominal pressure (IAP) result in irreversible tissue damage, monitoring IAP in critically ill patients using the common urinary bladder catheter method is essential. However, this method can result in complications and is not suitable for very low birth weight neonates. The aim of this study was to establish a non-invasive and accurate method to detect IAP changes using an animal model. (2) Methods: IAP changes via intra-abdominal air application (up to 20 mmHg) were measured in 19 Wistar rats via an intra-abdominally placed intracranial pressure probe. Concurrently, abdominal surface tension was measured using a Graseby capsule (GC). (3) Results: A high correlation between abdominal wall distension and IAP (r = 0.9264, CI 0.9249-0.9279) was found for all subjects. (4) Conclusions: IAP changes in rats can be detected non-invasively using a GC. However, further studies are necessary to assess whether IAP changes can be measured using a GC in the neonatal population.

THE EFFECT OF INTRA-ABDOMINAL PRESSURE EXPERIMENTAL CHANGES ON THE ULTRASTRUCTURE OF THE RAT'S LEVATOR ANI MUSCLE

In clinical practice, it is well known that an increase in intra-abdominal pressure can lead to disorders in the functioning of internal organs, cause the development of multiple organ failure and the formation of pelvic organ prolapse. Despite the fact that the pelvic bottom along with the muscles of the anterior abdominal wall and the diaphragm, takes an active part in the formation of intra-abdominal pressure, so far there are practically no morphological studies of the muscles of the pelvic diaphragm and their reactive changes that occur in response to an increase in intra-abdominal pressure. The aim of the study was to study the ultrastructural rearrangements of the levator ani muscle in response to experimentally formed states of increase and decrease in intra-abdominal pressure. The work was performed on 21 male outbred adult white laboratory rats. It has been established that after damage to the myofibrillar apparatus of the muscle fibers of the levator ani muscle in response to an increase in intra-abdominal pressure, the processes of sarcoplasmic adaptation and activation of the synthetic apparatus begin in them, which leads to a gradual restoration of their structure to its initial state. These changes are subject to certain time dynamics. 4 weeks after the increase in intra-abdominal pressure, a slight atrophy of the myofibrillar apparatus is observed and expansions of the intermyofibrillar cytoplasmic matrix appear. In mitochondria distinctly expressed irreversible changes in mitochondria occur, many mitochondria die. Subsequently, a significant amount of glycogen granules appears between the myofibrils, the structure of the myons is restored. Eight weeks after the start of the experiment, the structure of most muscle fibers is restored almost completely. The structure of the levator ani muscle did not change during the simulation of reduced intra-abdominal pressure in comparison with the control group at all periods of observation. In general, the study shows that the levator ani muscle skeletal muscle tissue has a high mechanic-dependent plasticity, which manifests itself in compensatory rearrangements of the ultrastructure of its fibers in response to changes in intra-abdominal pressure.

Re-discussion on the comprehensive treatment strategy of complex ventral hernia from the perspective of intraperitoneal pressure

Complex ventral hernia refers to a large hernia that is complicated by a series of concurrent conditions. Change in intra-abdominal pressure is one of the main pathways through which various factors exert an impact on perioperative risk and postoperative recurrence. Taking abdominal pressure reconstruction as the core, the treatment strategy for complex abdominal hernia can be formulated from three aspects: improving patients' tolerance, expanding abdominal cavity volume, and reducing the volume of abdominal contents. Improving patients' tolerance includes abdominal wall compliance training and progressive preoperative pneumoperitoneum. To expand the volume of the abdominal cavity, implanting hernia repair materials, component separation technique, autologous tissue transplantation, component expend technique, and chemical component separation can be used. Initiative content reduction surgery and temporary abdominal closure may be performed to reduce the volume of abdominal contents. For different cases of complex ventral hernia, personalized treatment measures can be safely and feasibly adopted depending on the condition of the patients and the intra-abdominal pressure situation.

INTRAABDOMINAL PRESSURE CHANGE UNDER ABDOMINAL SURGERY

Abstract. Statement of the problem. Intraabdominal hypertension (IAH) recognized as important consequence of surgery intraabdominal or on abdominal wall.&#x0D; For a pity there are no signs to predict the possibility of such a dangerous complication.&#x0D; Aim of study: to find out changes of intraabdominal pressure (IAP) corresponding to different kind of abdominal surgeries.&#x0D; Material and methods. IAP had been measured in 15 patients before, immediately after, and 1, and 3-4 days since open surgery. Also, IAP had been measured in 5 patients before and after laparoscopic surgeries.&#x0D; IAP was measured by urinal bladder way.&#x0D; Results and discussion. Before surgery IAP was find at level 10 cm Н2О or higher in 3 patients, but not higher than 15 cm in none of them.&#x0D; There was not estimated direct connection between IAP and diagnosis. Of 2 patients with large incisional hernia and abdominal wall defect 243 cm2 and 832 cm2 in size IAP before surgery was stated as 3 and 14 cm Н2О, respectively, while in the latter there were no any little of compression.&#x0D; There was no firm interconnection between anesthesia mode and IAP&#x0D; Immediately after surgery IAP became equal to 10 cm Н2О or higher in 13 patients, of them in 4 it was 20 cm Н2О or higher. On the next day after surgery IAP leveled to 10 cm Н2О or higher in 7 patients, of them in 3 it was 20 cm Н2О or higher. One of the latter died, all other patients survived.&#x0D; In all patients operated in laparoscopic way IAP measured through intrabladder catheter was 7-11 cm Н2О lower than those on insufflator manometer.&#x0D; Conclusions. IAP assay via urinary bladder pressure estimating is not the IAP measurement but indicator of urinary bladder tone.&#x0D; As high IAP in many cases correspond to patient’s grave condition and even death it is of importance to study the real reason of this indicator.

The spine intra-abdominal pressure (SIAP) trial. A prospective, observational, single arm, monocenter study looking at the evolutions of the IAP prior, during and after spine surgery

Background and aimsBoth anaesthesiologists and spine surgeons consider the intra-abdominal pressure (IAP) as an important peri-operative factor affected by patient positioning.We assessed the change in IAP caused by using a thoraco pelvic support (inflatable prone support, IPS) with the subject under general anesthesia. The IAP was measured before, during and immediately after surgery. MethodsThe Spine Intra-Abdominal Pressure study (SIAP trial) is a prospective, single-arm, monocenter, observational study looking at changes in IAP prior, during and after spine surgery. The objective is to assess the change in IAP, measured via an indwelling urinary catheter, using the inflatable prone support (IPS) device during prone positioning of patients in spinal surgery. ResultsForty (40) subjects requiring elective lumbar spine surgery in prone position were enrolled after providing informed consent. The inflation of the IPS results in a significant decrease of IAP (from a median of 9.2 mmHg to 6.46 mmHg (p < 0.001)) in patients undergoing spine surgery in prone position. This decrease in IAP was maintained throughout the procedure despite the discontinuation of muscle relaxants. No serious adverse events or unexpected adverse events occurred. ConclusionThe use of the thoraco-pelvic support IPS device was able to significantly lower the IAP during spine surgery.

FACTORS INCREASING INTRA-ABDOMINAL PRESSURE IN PATIENTS WITH A COMPLICATED COURSE OF ACUTE PANCREATITIS

Relevance. The frequency of development of intra-abdominal hypertension in patients with a complicated course of acute pancreatitis is 60-70% and leads to an increase in the mortality rate up to 62%. Acute peripancreatic fluid collection, occurring in 65.2-88.9% of patients with moderate and severe acute pancreatitis in the early period of the disease, is one of the causes of increased intra-abdominal pressure.&#x0D; Objective: to assess the effect of acute peripancreatic fluid collection on intra-abdominal pressure and the effectiveness of paracentesis with drainage of the abdominal cavity as a method of treatment of intra-abdominal hypertension in patients with complicated course of acute pancreatitis in the early period of the disease.&#x0D; Methods. The study included 60 patients with a complicated course of acute pancreatitis, who were divided into two groups depending on the features of the selected treatment tactics: the main group (paracentesis, drainage of the abdominal cavity was additionally performed) – 30 patients, the comparison group (conservative therapy was applied) - 30 patients. Intra-abdominal pressure indicators were compared in the studied groups and performed a comparative analysis of the dependence of its changes on the amount of exudate removed from the abdominal cavity.&#x0D; Results. When using paracentesis and drainage of the abdominal cavity in the early period in patients with a complicated course of acute pancreatitis, a significant difference was obtained between the intra-abdominal pressure indicators in the studied groups after one day (8.7±1.5 vs. 14.7±3.3 mm Hg (p&lt;0.0001)) and after 7 days (10.5±1.3 vs. 12.7±2.5 mm Hg (p=0.0001)). In the patients of the main group, a decrease in intra-abdominal pressure was observed on the first day after paracentesis, followed by an increase after three days and stabilization after 6 days, and an average negative correlation was found between the amount of exudate removed from the abdominal cavity and changes in intra-abdominal pressure with the Pearson coefficient r = - 0.4418.&#x0D; Conclusions. The use of paracentesis, drainage of the abdominal cavity in patients with complicated course of acute pancreatitis in the early period of the disease can be considered as a safe and effective method of treatment of intra-abdominal hypertension in this category of patients.

A 3D finite element model of uterus support to evaluate mechanisms underlying uterine prolapse formation

Uterine prolapse (UP) seriously affects the quality of life and physical and mental health of elderly women, which can easily be caused by ligament injury or intra-abdominal pressure (IAP) increasing. The objective of this manuscript was to study the influence of IAP and ligament injury on uterus and its surrounding ligaments using the finite element method. First, the three-dimensional (3D) models of retroverted uterus and its surrounding ligaments were established, and loads and constraints were set in ABAQUS software, then the stress and deformation of uterine ligaments and uterine displacement were calculated. The study found that the uterine displacement and the stress and deformation of the ligaments increased when IAP and ligament injury increased alone or simultaneously. Then, the stress and sensitivity of the ligaments to the changes of IAP or ligament injury were in the order of uterosacral ligament (USL), broad ligament (BL), cardinal ligament (CL) and round ligament (RL), while the deformation and sensitivity the changes of the ligaments were in the order of BL > RL > USL > CL. Moreover, the ligament injury had a greater influence on the uterus and uterine ligaments than IAP. The results of this study can provide guidance for optimization of surgical scheme of uterus prolapsed in clinic and exploration of pathogenesis.

Assessment of changes in intra-abdominal pressure and abdominal perfusion pressure in late-term pregnant queens undergoing elective ovariohysterectomy.

Compare changes in intra-abdominal pressure (IAP), abdominal perfusion pressure (APP), hemodynamics, and clinicopathological variables in nonpregnant and late-term pregnant queens undergoing elective ovariohysterectomy (OHE) and evaluate the effect of patient positioning on IAP and APP measurements. 18 late-term pregnant queens and 25 nonpregnant controls. Temperature, heart rate (HR), Doppler blood pressure (DBP), IAP (dorsal and right lateral), PCV, total protein (TP), and lactate were recorded preoperatively, at abdominal wall closure (dorsal IAP only), and postoperatively under general anesthesia. Uterine weight, blood loss, and surgical duration were recorded. Abdominal perfusion pressure was calculated as DBP minus IAP. Pre- and postoperatively, pregnant queens had lower DBP, APP, and PCV compared to controls (P < 0.001). IAP was higher in pregnant queens preoperatively (P < 0.001). Controls had a decrease in HR and increase in IAP, while both groups had a decrease in body temperature, DBP, APP, and lactate over time (P < 0.05). Pregnant queens had a decrease (P = 0.029), and controls had an increase in TP (P = 0.001). Blood loss and surgical time were greater for pregnant queens (P < 0.001). Dorsal IAP and APP were higher and lower than right lateral measurements (P < 0.001), respectively, and correlation was strong. Hemodynamics and APP are impaired in late-term pregnant queens undergoing OHE, and increased monitoring is warranted. Although strongly correlated, feline IAP and APP measurements in dorsal and right lateral recumbency are not interchangeable.

Non-invasive cardiac output monitoring before and after baby extubation – A feasibility study (NICOMBabe study)

BackgroundMechanical ventilation induces changes in intrapleural, intrathoracic and intra-abdominal pressure. These changes have various implications on cardiac output (CO). AimsThe aim of this study was to determine the feasibility of measuring changes in CO after elective extubation in neonates using the principle of transthoracic bioreactance (TBR). Study designThis was a prospective observational cohort study in a level III neonatal centre. CO, stroke volume (SV) and heart rate were measured continuously for 2 h before and 2 h after elective extubation by TBR. SubjectsNeonates undergoing elective extubation were eligible for enrolment. Outcome measuresThe primary outcome of the study was change in CO post elective extubation. ResultsTen neonates were enrolled, seven (70 %) had a statistically significant decrease in CO after extubation, three (30 %) infants had a statistically significant increase in CO after extubation. Changes in CO were primarily driven by changes in SV and the pattern of change was related to patent ductus arteriosus (PDA) status prior to extubation. ConclusionExtubation significantly influences CO in neonatal patients and the pattern of change appears to be related to PDA status.

Assessment of effects of intra-abdominal pressure monitoring on evaluating early enteral nutrition in patients with acute pancreatitis

To explore the role of intra-abdominal pressure (IAP) monitoring in evaluating the efficacy of early enteral nutrition (EN) in patients with acute pancreatitis (AP). The clinical data were collected from the AP patients in department of criticle care medicine of Baoshan Branch of Huashan Hospital Affiliated to Fudan University from July 2020 to June 2021. The patients were divided into three groups according to their treatments: no gastrointestinal decompression with fasting group, gastrointestinal decompression with fasting group, gastrointestinal decompression with indwelling jejunal tube within 24 hours group. The data of white blood cell (WBC), procalcitonin (PCT), serum amylase (AMY) and IAP were analyzed before and after treatment, the initiation time oral feeding were also analyzed. The decrease of WBC, PCT, AMY, and IAP in gastrointestinal decompression with indwelling jejunal tube within 24 hours group were significantly greater than those in the other groups [WBC (×109/L): -1.72±0.74 vs. -0.68±0.36, -1.23±86.97; PCT (μg/L): -3.14±5.19 vs. 0.06±0.48, -1.57±0.78; AMY (U): -148.43±75.89 vs. -74.85±78.84, -93.78±1.17; IAP (cmH2O, 1 cmH2O ≈ 0.098 kPa): -4.82±1.66 vs. 0.36±1.32, -3.22±4.36, all P < 0.05]. There were no correlation between the changes of IAP and the changes of WBC, PCT or AMY in the non-gastrointestinal decompression with fasting group and the gastrointestinal decompression with indwelling jejunal tube within 24 hours group (all P > 0.05). The decreasing trend of IAP in patients with gastrointestinal decompression with fasting group was positively correlated with the change of AMY (r = 0.65, P < 0.001). The initiation time of oral feeding in gastrointestinal decompression with indwelling jejunal tube within 24 hours group was significantly shorter than that in the other groups (hours: 89.538 vs. 111.273, 109.714), the difference was statistically significant (P < 0.05). IAP monitoring, as an emergency means of monitoring the efficacy of early EN in AP patients, has the advantages of simplicity, efficiency and rationality, which has a more objective basis than the previous empirical treatment and open oral feeding.

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.

Immediate changes in intra-abdominal pressure and lung indicators in patients undergoing complex ventral hernia repair with the transversus abdominis muscle release, with and without preoperative botulinum toxin.

The current treatment of complex ventral hernias involves muscle closure with components separation techniques and mesh placement. The purpose of this study is to evaluate the immediate postoperative changes in the intra-abdominal pressure (IAP), and lung indicators after treatment of complex ventral hernias with the transversus abdominis reléase (TAR) technique. All patients with complex ventral hernias treated between November 28th, 2016 and October 6th, 2021 were initially included. We excluded patients with lung and/or heart comorbidities. A total of 43 patients were studied, measuring IAP, lung compliance, pulmonary plateau pressure (PPP), and end-tidal CO2 before and after surgical treatment. Median IAP increased from 5to 9mmHg (p < 0.0001), and PPP from 11to 12mmHg (p = 0.004). Increased body mass index (BMI) was associated to a PPP increase above normal values. Postoperative changes were not different in patients receiving preoperative preparation with botulinum toxin. After complex ventral hernia closure, there is an immediate impact on IAP and PPP, the latter more frequent in patients with the highest BMI, and this maynot be prevented by the preoperative administration of botulinum toxin.

Randomized controlled trial: neostigmine for intra-abdominal hypertension in acute pancreatitis

BackgroundIntra-abdominal hypertension (IAH) in acute pancreatitis (AP) is associated with deterioration in organ function. This trial aimed to assess the efficacy of neostigmine for IAH in patients with AP.MethodsIn this single-center, randomized trial, consenting patients with IAH within 2 weeks of AP onset received conventional treatment for 24 h. Patients with sustained intra-abdominal pressure (IAP) ≥ 12 mmHg were randomized to receive intramuscular neostigmine (1 mg every 12 h increased to every 8 h or every 6 h, depending on response) or continue conventional treatment for 7 days. The primary outcome was the percent change of IAP at 24 h after randomization.ResultsA total of 80 patients were recruited to neostigmine (n = 40) or conventional treatment (n = 40). There was no significant difference in baseline parameters. The rate of decrease in IAP was significantly faster in the neostigmine group compared to the conventional group by 24 h (median with 25th–75th percentile: −18.7% [− 28.4 to − 4.7%] vs. − 5.4% [− 18.0% to 0], P = 0.017). This effect was more pronounced in patients with baseline IAP ≥ 15 mmHg (P = 0.018). Per-protocol analysis confirmed these results (P = 0.03). Stool volume was consistently higher in the neostigmine group during the 7-day observational period (all P < 0.05). Other secondary outcomes were not significantly different between neostigmine and conventional treatment groups.ConclusionNeostigmine reduced IAP and promoted defecation in patients with AP and IAH. These results warrant a larger, placebo-controlled, double-blind phase III trial.Trial registration Clinical Trial No: NCT02543658 (registered August /27, 2015).

Deep breathing couples CSF and venous flow dynamics

Venous system pathologies have increasingly been linked to clinically relevant disorders of CSF circulation whereas the exact coupling mechanisms still remain unknown. In this work, flow dynamics of both systems were studied using real-time phase-contrast flow MRI in 16 healthy subjects during normal and forced breathing. Flow evaluations in the aqueduct, at cervical level C3 and lumbar level L3 for both the CSF and venous fluid systems reveal temporal modulations by forced respiration. During normal breathing cardiac-related flow modulations prevailed, while forced breathing shifted the dominant frequency of both CSF and venous flow spectra towards the respiratory component and prompted a correlation between CSF and venous flow in the large vessels. The average of flow magnitude of CSF was increased during forced breathing at all spinal and intracranial positions. Venous flow in the large vessels of the upper body decreased and in the lower body increased during forced breathing. Deep respiration couples interdependent venous and brain fluid flow—most likely mediated by intrathoracic and intraabdominal pressure changes. Further insights into the driving forces of CSF and venous circulation and their correlation will facilitate our understanding how the venous system links to intracranial pressure regulation and of related forms of hydrocephalus.

Percutaneous delivery of self-propelling hemostatic powder for managing non-compressible abdominal hemorrhage: a proof-of-concept study in swine

IntroductionNon-compressible intra-abdominal hemorrhage (NCIAH) is a major cause of preventable death on the battlefield and in civilian trauma. Currently, it can only be definitively managed with surgery, as there are limited strategies for controlling ongoing NCIAH in the prehospital environment. We hypothesized that a self-propelling thrombin-containing powder (SPTP) could increase survival in a swine model of NCIAH when delivered percutaneously into the closed abdomen using an engineered spray system. Materials and MethodsNineteen swine underwent surgical laparotomy followed by a Grade V liver injury that created massive hemorrhage, before closing the abdomen with sutures. Animals either received treatment with standard of care fluid resuscitation (n=9) or the SPTP spray system (n=10), which consisted of a spray device and a 14 Fr catheter. Using the spray system, SPTP was delivered into a hemoperitoneum identified using a focused assessment with sonography in trauma (FAST) exam. Lactated Ringer's solution was administered to all animals to maintain a mean arterial pressure (MAP) of >50 mmHg. The primary outcome was percentage of animals surviving at three hours following injury. ResultsIn the swine model of NCIAH, a greater percentage of animals receiving SPTP survived to three hours, although differences were not significant. The SPTP spray system increased the median survival of animals from 1.6 hr in the fluid resuscitation group to 4.3 hr. The SPTP spray system delivered a total mass of 18.5 ± 1.0 g of SPTP. The mean change in intra-abdominal pressure following SPTP delivery was 5.2 ± 1.8 mmHg (mean ± SEM). The intervention time was 6.7 ± 1.7 min. No adverse effects related to the SPTP formulation or the spray system were observed. SPTP was especially beneficial in animals that had either severely elevated lactate concentrations or low mean arterial pressure of <35 mmHg shortly after injury. ConclusionsThis demonstrates proof-of-concept for use of a new minimally invasive procedure for managing NCIAH, which could extend survival time to enable patients to reach definitive surgical care.