Intra-abdominal pressure and residual renal function decline in peritoneal dialysis: a threshold-based investigation

BACKGROUND

The potential impact of elevated intra-abdominal pressure (IAP) on residual renal function (RRF) has not been determined. The objective of this study was to investigate the relationship between IAP and the rate of RRF decline in newly initiated peritoneal dialysis (PD) patients, and to identify the optimal IAP threshold value for delaying the deterioration of RRF.

METHODS

A cohort of 62 newly initiated PD patients who completed both 6- and 12-month follow-up evaluations was obtained using the Durand method. A logistic regression model was used to identify variables associated with a rapid decline in RRF. Receiver operating characteristic (ROC) curves were generated to determine the optimal threshold value. Another retrospective cohort analysis was performed to validate the identified critical value.

RESULTS

For each 1 cmH2O increase in IAP, the risk of a rapid decline in the RRF increased by a factor of 1.679. Subsequent analysis revealed that patients in the high IAP group had more significant decreases in residual renal estimated glomerular filtration rate (eGFR) (Z = -3.694, p < 0.001) and urine volume (Z = -3.121, p < 0.001) than did those in the non-high IAP group. Furthermore, an IAP ≥15.65 cmH2O was a robust discriminator for the prediction of the rate of RRF decline.

CONCLUSION

Patients in the high IAP group experienced a more rapid decline in RRF. Additionally, an optimal critical pressure of 15.65 cmH2O was identified for predicting the rate of RRF decline. IAP, as one of the factors contributing to the rapid decline in RRF in the first year of PD, should be given due attention.

Does a jammer-type racing swimsuit improve sprint performance during maximal front-crawl swimming?

We investigated the effects of jammer-type racing swimsuits (RS) on swimming performance during arm-stroke-only (pull) and whole-body stroke (swim) in 25-m front-crawl with maximal effort. Twelve well-trained male collegiate swimmers wore RS and a conventional swimsuit (CS) and performed three tests: pull, swim, and pull using the system to measure active drag (MAD pull). Swimming velocity and intra-abdominal pressure (IAP) were determined in all tests. Stroke indices during pull and swim and drag-swimming velocity relationship and maximum propulsive power during MAD pull were also determined. Swimming velocities during pull and swim while wearing an RS (1.59 ± 0.13 and 1.77 ± 0.09 m·s-1, respectively) were significantly higher than those wearing a CS (1.57 ± 0.14 and 1.74 ± 0.08 m·s-1, respectively). Stroke length during pull and swim was significantly greater while wearing an RS (1.68 ± 0.12 and 1.83 ± 0.13 m, respectively) than wearing a CS (1.63 ± 0.10 and 1.81 ± 0.13 m, respectively). However, no significant differences were confirmed between the other variables in all tests. In conclusion, swimming performance is improved when wearing an RS compared with a CS.

Transcutaneous Hitching Sutures in Paediatric Minimally Invasive Surgery: A Novel Technique of "Assistant Without Port"

BACKGROUND

Transcutaneous hitching sutures in paediatric minimally invasive surgery (MIS) is a unique and rare technique. This technique has been used previously in adult patients undergoing gastric resections and laparoscopic cholecystectomy; however, its use in paediatric population has never been reported in the world literature. The primary objective of this study was to bring out the advantages and feasibility of this technique in minimally invasive gastrointestinal, hepatobiliary, urological and thoracoscopic surgeries on paediatric patients.

MATERIALS AND METHODS

This retrospective observational study was conducted on 167 paediatric patients who underwent MIS surgery for different indications between April 2016 and March 2020 at two paediatric surgery tertiary care centres.

RESULTS

A total of 167 patients, including 91 boys and 76 girl patients between the age group of new-born period to 12 years were operated. The mean hospital stay was 4 days. Five out of 167 cases (3%) had post-operative surgical emphysema, which resolved spontaneously. At 6-month follow-up, parental satisfaction was 100%, and in 99% of patients, scars were imperceptible.

CONCLUSION

This versatile technique is of exemplary utility, especially in paediatric patients where there is a paucity of working space at low intra-abdominal pressure, and eases the dissection even in narrow and closed spaces with a better functional and cosmetic outcome.

An estimation of the biomechanical properties of the continent and incontinent woman bladder via inverse finite element analysis

Stress urinary incontinence often results from pelvic support structures' weakening or damage. This dysfunction is related to direct injury of the pelvic organ's muscular, ligamentous or connective tissue structures due to aging, vaginal delivery or increase of the intra-abdominal pressure, for example, defecation or due to obesity. Mechanical changes alter the soft tissues' microstructural composition and therefore may affect their biomechanical properties. This study focuses on adapting an inverse finite element analysis to estimate the in vivo bladder's biomechanical properties of two groups of women (continent group (G1) and incontinent group (G2)). These properties were estimated based on MRI, by comparing measurement of the bladder neck's displacements during dynamic MRI acquired in Valsalva maneuver with the results from inverse analysis. For G2, the intra-abdominal pressure was adjusted after applying a 95% impairment to the supporting structures. The material parameters were estimated for the two groups using the Ogden hyperelastic constitutive model. Finite element analysis results showed that the bladder tissue of women with stress urinary incontinence have the highest stiffness (α1 = 0.202 MPa and µ1 = 7.720 MPa) approximately 47% higher when compared to continent women. According to the bladder neck's supero-inferior displacement measured in the MRI, the intra-abdominal pressure values were adjusted for the G2, presenting a difference of 20% (4.0 kPa for G1 and 5.0 kPa for G2). The knowledge of the pelvic structures' biomechanical properties, through this non-invasive methodology, can be crucial in the choice of the synthetic mesh to treat dysfunction when considering personalized options.

Prevalence of increased intra-abdominal pressure and its impact on renal function in acute decompensated heart failure: A prospective pilot study

BACKGROUND

Intra-abdominal pressure (IAP) is a frequently overlooked aspect in clinical assessment that can have a significant impact on organ dysfunction in patients with acute decompensated heart failure (ADHF).

AIMS

We aimed to investigate dynamics of IAP in patients with ADHF and its impact on diuretic response.

METHODS

We conducted a prospective observational pilot study on a group consisting of 30 patients admitted for ADHF. In every individual IAP measurement, blood and urine samples were taken upon admission, on the second and third days of hospitalization.

RESULTS

The study showed a high (63.3%) prevalence of intra-abdominal hypertension (IAH) defined as IAP ≥12 mm Hg upon admission, while only roughly 13% had signs of ascites. We observed poorer diuresis on the first day of hospitalization in the IAH group (P = 0.03). IAP was negatively correlated with urine output (P = 0.01) and positively correlated with urine osmolality (P = 0.03) on the first day of hospitalization. During follow-up, there was a significant decrease in IAP in patients with IAH upon admission who received standard decongestive therapy.

CONCLUSIONS

The study shows a high prevalence of IAH in patients admitted for ADHF, even in individuals who do not present symptoms of abdominal congestion. Established correlation between IAP, reduced diuresis, and increased urine osmolality, despite achieving target natriuresis, contributes novel insights into the understanding of pathomechanisms underlying diuretic resistance in ADHF.

Adjuvant Botulinum Toxin Type A on the Management of Giant Hiatal Hernia: A Case Report

The management of giant hiatal hernias (HHs) remains challenging and is associated with a high risk of recurrence. Currently, several strategies are used to reduce recurrence, and a newly proposed trend is the administration of adjuvant botulinum toxin type A (BTX), a procedure already performed in complex ventral hernias. Here, we present a case of a 63-year-old man with a giant paraesophageal HH type IV containing the entire stomach and transverse colon with loss of domain, who underwent adjuvant BTX and subsequently laparoscopic hiatoplasty with a biological mesh with partial fundoplication. At six months' follow-up, the patient reported a significant improvement in the quality of life without dysphagia or gastroesophageal reflux and with a good respiratory function. A control computed tomography was performed, which documented a partial recurrence of HH, completely asymptomatic. This clinical case showed the successful treatment of a giant HH using adjuvant BTX injection to increase abdominal wall compliance as had already been described in the treatment of complex ventral hernia. Thus, the use of BTX is a promising strategy for selected cases of giant HHs mainly if there is a loss of domain; however, more case series and controlled trials are needed to show the reproducibility of the benefit of this strategy.

Intra-abdominal Pressure Measurement as a Predictor of Postoperative Wound Complications in Patients Undergoing Emergency Laparotomy: A Prospective Observational Study

Introduction Elevated intra-abdominal pressure (IAP) hampers the effective functioning of intra- and extra-abdominal organs. Despite the abundance of knowledge, routine measurement of IAP still needs to be widely incorporated in managing at-risk patients. The present study intends to assess the need for IAP measurement on abdominal wound healing in emergency laparotomy patients. Methods This prospective study was carried out over 24 months in patients undergoing emergency laparotomy. The IAP was measured at admission, immediately after surgery, and during the early postoperative period at 6, 12, 24, 48, and 72 hours. The patients were evaluated for the development of wound-related complications over a follow-up period of three months post-operatively. Results Seventy-two patients were enrolled. At admission, 54 (75%) patients had intra-abdominal hypertension (IAH), of which three patients had evidence of abdominal compartment syndrome. Thirty-one (43%) patients developed postoperative wound infections. The overall incidence of wound infection was significantly higher in patients with IAH (54.3% vs. 24%, p-value = 0.04, Pearson's Chi-squared test). The frequency of wound dehiscence was greater (19.6 % vs. 4.3 %, p-value 0.14, Fischer's exact test) in patients with IAH. The median duration of hospital stay (13 vs. 8 days, p-value 0.02, Mann-Whitney U test) and healing time (30.5 vs. 18 days, p-value 0.02, Mann-Whitney U test) was significantly higher in patients with IAH. Conclusion Measurement of IAP is a relatively simple procedure that should be incorporated into the routine postoperative care of surgical patients. The presence of elevated IAP can identify the subset of patients at risk of increased postoperative wound complications.

Assessment of the Smartpill, a Wireless Sensor, as a Measurement Tool for Intra-Abdominal Pressure (IAP)

Background: The SmartPill, a multisensor ingestible capsule, is marketed for intestinal motility disorders. It includes a pressure sensor, which could be used to study intra-abdominal pressure (IAP) variations. However, the validation data are lacking for this use. Material and Methods: An experimental study was conducted on anesthetized pigs with stepwise variations of IAP (from 0 to 15 mmHg by 3 mmHg steps) generated by laparoscopic insufflation. A SmartPill, inserted by endoscopy, provided intragastric pressure data. These data were compensated to take into account the intrabdominal temperature. They were compared to the pressure recorded by intragastric (IG) and intraperitoneal (IP) wired sensors by statistical Spearman and Bland-Altmann analysis. Results: More than 4500 pressure values for each sensor were generated on two animals. The IG pressure values obtained with the SmartPill were correlated with the IG pressure values obtained with the wired sensor (respectively, Spearman ρ coefficients 0.90 ± 0.08 and 0.72 ± 0.25; bias of -28 ± -0.3 mmHg and -29.2 ± 0.5 mmHg for pigs 1 and 2). The intragastric SmartPill values were also correlated with the IAP measured intra-peritoneally (respectively, Spearman ρ coefficients 0.49 ± 0.18 and 0.57 ± 0.30; bias of -29 ± 1 mmHg and -31 ± 0.7 mmHg for pigs 1 and 2). Conclusions: The SmartPill is a wireless and painless sensor that appears to correctly monitor IAP variations.

Effects of External Abdominal Pressure Support on Dynamic Balance: A Randomized Crossover Study

Abdominal pressure is vital in protecting the lumbar spine and controlling postural balance. Dynamic balance is associated with movement stability, adaptation to load, and reduced injury risk. Although trunk stability has been examined using belts and braces, the effects of external abdominal pressure support (APS) on balance control remain unknown. In this study, we aimed to determine the effects of external APS on dynamic balance. Overall, 31 young adults participated in this randomized crossover study. External APS was provided using a device that could be pressurized and decompressed by inflating a cuff belt wrapped around the trunk. The modified Star Excursion Balance Test was performed under external APS and non-APS conditions. The maximum anterior, posterolateral, and posteromedial values normalized to the spinal malleolar distance and their respective composite values were compared between the two conditions with and without APS. Posterolateral, posteromedial, and composite values were significantly higher in the APS condition than in the non-APS condition (p < 0.001). The external APS was effective in immediately improving dynamic balance. Furthermore, APS was effective in dynamic balance control as it improved stability during anterior trunk tilt, which displaces the center of gravity forward.

Abdominal Hypertension after Abdominal Plication in Postbariatric Patients: The Consequence in the Postoperative Recovery

Background  Abdominoplasty with abdominal plication increases intra-abdominal pressure (IAP) and has been previously associated with limited diaphragmatic excursion and respiratory dysfunctions. Many factors found in abdominoplasties and among postbariatric patients predispose them to a higher occurrence. This study aims to evaluate the impact of abdominal plication among postbariatric patients, assess whether the plication increases their IAP, and analyze how these IAP correlate to their postoperative outcome. Methods  This prospective study was performed on all patients who underwent circumferential Fleur-De-Lis abdominoplasty. For this intended study, the IAP was measured by an intravesical minimally invasive approach in three stages: after the initiation of general anesthesia, after a 10-cm abdominal wall plication and skin closure, and 24 hours after the procedure. Results  We included 46 patients, of which 41 were female and 5 were male. Before the bariatric procedure, these patients had an average maximum weight of 121.4 kg and an average maximum body mass index of 45.78 kg/m 2 ; 7 were grade I obese patients, 10 were grade II, and 29 were grade III. Only three patients were operated on with a gastric sleeve and 43 with gastric bypass. We presented six patients with transitory intra-abdominal hypertension in the first 24 hours, all of them from the grade I obesity group, the highest presented was 14.3 mm Hg. We presented 15% (7/46) of complication rates, which were only four seroma and five dehiscence; two patients presented both seroma and wound dehiscence. Conclusion  Performing a 10-cm abdominal wall plication or greater represents a higher risk for intra-abdominal hypertension, slower general recovery, and possibly higher complication rate in patients who presented a lower degree of obesity (grade I) at the moment of the bariatric surgery.

Evaluation of the TraumaGuard Balloon-in-Balloon Catheter Design for Intra-Abdominal Pressure Monitoring: Insights from Pig and Human Cadaver Studies

Introduction: Intra-abdominal pressure (IAP) monitoring is crucial for the detection and prevention of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS). In the 1970s, air-filled catheters (AFCs) for urodynamic studies were introduced as a solution to overcome the limitations of water-perfused catheters. Recent studies have shown that for correct IAP measurement with traditional AFC, the bladder needs to be primed with 25 mL of saline solution to allow pressure wave transmission to the transducer outside of the body, which limits continuous IAP monitoring. Methods: In this study, a novel triple balloon, air-filled TraumaGuard (TG) catheter system from Sentinel Medical Technologies (Jacksonville, FL, USA) with a unique balloon-in-balloon design was evaluated in a porcine and cadaver model of IAH via laparoscopy (IAPgold). Results: In total, 27 and 86 paired IAP measurements were performed in two pigs and one human cadaver, respectively. The mean IAPTG was 20.7 ± 10.7 mmHg compared to IAPgold of 20.3 ± 10.3 mmHg in the porcine study. In the cadaver investigation, the mean IAPTG was 15.6 ± 10.8 mmHg compared to IAPgold of 14.4 ± 10.4 mmHg. The correlation, concordance, bias, precision, limits of agreement, and percentage error were all in accordance with the WSACS (Abdominal Compartment Society) recommendations and guidelines for research. Conclusions: These findings support the use of the TG catheter for continuous IAP monitoring, providing early detection of elevated IAP, thus enabling the potential for prevention of IAH and ACS. Confirmation studies with the TraumaGuard system in critically ill patients are warranted to further validate these findings.

Cardiovascular and Respiratory Effects of Increased Intra-Abdominal Pressure with and without Dexmedetomidine in Anesthetized Dogs

Intra-abdominal pressure (IAP) elevation during capnoperitoneum can cause adverse cardiovascular and respiratory effects. This study aimed to determine if a sequentially increased IAP affects cardiovascular and respiratory variables in anesthetized dogs and evaluate the effects of the constant-rate infusion of dexmedetomidine (Dex) on cardiovascular and respiratory variables with increased IAP. Five dogs were anesthetized and instrumented, and a Veress needle was equipped to adjust the IAP using a carbon dioxide insufflator. Stabilization was conducted for 1 h, and physiological variables were measured at IAPs of 0, 5, 10, 15, and 20 mmHg and after desufflation. After the washout period, the dogs underwent similar procedures along with a constant-rate infusion of dexmedetomidine. The cardiovascular effects of increased IAP up to 20 mmHg were not significant in healthy beagle dogs and those administered with dexmedetomidine. When comparing the control and dexmedetomidine groups, the overall significant effects of dexmedetomidine were noted on heart rate, cardiac output, and systemic vascular resistance during the experiment. Respiratory effects were not observed during abdominal insufflation when compared between different IAPs and between the two groups. Overall, an increased IAP of up to 20 mmHg did not significantly affect cardiovascular and respiratory variables in both the control and dexmedetomidine groups. This study suggests that the administration of a dexmedetomidine infusion is applicable in laparoscopic procedures in healthy dogs.

Abdominal Compartment Syndrome Secondary to Constipation in an Adult Patient With Cerebral Palsy

The majority of patients with constipation can often be treated conservatively with laxatives, suppositories, or enemas in mild cases. However, endoscopic decompression or surgical intervention may be required in some instances. Abdominal compartment syndrome as a result of constipation is rarely seen in the literature. We report a case of faecal impaction, which led to abdominal compartment syndrome in an adult patient with cerebral palsy. With increasing life expectancy, such cases may be increasingly encountered in the adult population. Severe complications of constipation should not be overlooked, especially in this at-risk population. Early recognition of abdominal compartment syndrome is key in its management.

In Vitro Validation of a Novel Continuous Intra-Abdominal Pressure Measurement System (TraumaGuard)

Introduction: Intra-abdominal pressure (IAP) has been recognized as an important vital sign in critically ill patients. Due to the high prevalence and incidence of intra-abdominal hypertension in surgical (trauma, burns, cardiac) and medical (sepsis, liver cirrhosis, acute kidney injury) patients, continuous IAP (CIAP) monitoring has been proposed. This research was aimed at validating a new CIAP monitoring device, the TraumaGuard from Sentinel Medical Technologies, against the gold standard (height of a water column) in an in vitro setting and performing a comparative analysis among different CIAP measurement technologies (including two intra-gastric and two intra-bladder measurement devices). A technical and clinical guideline addressing the strengths and weaknesses of each device is provided as well. Methods: Five different CIAP measurement devices (two intra-gastric and three intra-vesical), including the former CiMON, Spiegelberg, Serenno, TraumaGuard, and Accuryn, were validated against the gold standard water column pressure in a bench-top abdominal phantom. The impacts of body temperature and bladder fill volume (for the intra-vesical methods) were evaluated for each system. Subsequently, 48 h of continuous monitoring (n = 2880) on top of intermittent IAP (n = 300) readings were captured for each device. Using Pearson's and Lin's correlations, concordance, and Bland and Altman analyses, the accuracy, precision, percentage error, correlation and concordance coefficients, bias, and limits of agreement were calculated for all the different devices. We also performed error grid analysis on the CIAP measurements to provide an overview of the involved risk level due to wrong IAP measurements and calculated the area under the curve and time above a certain IAP threshold. Lastly, the robustness of each system in tracking the dynamic variations of the raw IAP signal due to respirations and heartbeats was evaluated as well. Results: The TraumaGuard was the only technology able to measure the IAP with an empty artificial bladder. No important temperature dependency was observed for the investigated devices except for the Spiegelberg, which displayed higher IAP values when the temperature was increased, but this could be adjusted through recalibration. All the studied devices showed excellent ability for IAP monitoring, although the intra-vesical IAP measurements seem more reliable. In general, the TraumaGuard, Accuryn, and Serenno showed better accuracy compared to intra-gastric measurement devices. On average, biases of +0.71, +0.93, +0.29, +0.25, and -0.06 mm Hg were observed for the CiMON, Spiegelberg, Serenno, TraumaGuard, and Accuryn, respectively. All of the equipment showed percentage errors smaller than 25%. Regarding the correlation and concordance coefficients, the Serenno and TraumaGuard showed the best results (R2 = 0.98, p = 0.001, concordance coefficient of 99.5%). Error grid analysis based on the Abdominal Compartment Society guidelines showed a very low associated risk level of inappropriate treatment strategies due to erroneous IAP measurements. Regarding the dynamic tracings of the raw IAP signal, all the systems can track respiratory variations and derived parameters; however, the CiMON was slightly superior compared to the other technologies. Conclusions: According to the research guidelines of the Abdominal Compartment Society (WSACS), this in vitro study shows that the TraumaGuard can be used interchangeably with the gold standard for measuring continuous IAP, even in an empty artificial bladder. Confirmation studies with the TraumaGuard in animals and humans are warranted to further validate these findings.

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.

Perioperative Renal Ultrasonography of Arterio-to-Venous Coupling Predicts Postoperative Complications after Major Laparoscopic Urologic Surgery

Point-of-care ultrasonography (POCUS) with concomitant venous and arterial Doppler assessment enables clinicians to assess organ-specific blood supply. To date, no studies have investigated the usefulness of including a comprehensive perioperative POCUS assessment of patients undergoing major laparoscopic surgery. The primary aim of the present study was to evaluate whether the combined venous and arterial renal flow evaluation, measured at different time points of perioperative period, may represent a clinically useful non-invasive method to predict postoperative acute kidney injury (AKI) after major laparoscopic urologic surgery. The secondary outcome was represented by the development of any postoperative complication at day 7. We included 173 patients, subsequently divided for analysis depending on whether they did (n = 55) or did not (n = 118) develop postoperative AKI or any complications within the first 7 days. The main results of the present study were that: (1) the combination of arterial hypoperfusion and moderate-to-severe venous congestion inferred by POCUS were associated with worst outcomes (respectively, HR: 2.993, 95% CI: 1.522-5.884 and HR: 8.124, 95% CI: 3.542-18, p < 0.001); (2) high intra-operative abdominal pressure represents the only independent determinant of postoperative severe venous congestion (OR: 1.354, 95% CI: 1.017-1.804, p = 0.038); (3) the overall number of complications relies on the balance between arterial inflow and venous outflow in order to ensure the adequacy of peripheral perfusion; and (4) the overall reliability of splanchnic perfusion assessment by Doppler is high with a strong inter-rater reliability (ICC: 0.844, 95% CI: 0.792-0.844). The concomitant assessment of arterial and venous Doppler patterns predicts postoperative complications after major laparoscopic urologic surgery and may be considered a useful ultrasonographic biomarker to stratify vulnerable patients at risk for development of postoperative complications.

Evaluation of Intra-Abdominal Hypertension Parameters in Patients with Acute Pancreatitis

BACKGROUND

Patients with acute pancreatitis develop numerous complications and organ damage due to increased intra-abdominal pressure (IAP). These extrapancreatic complications determine the clinical outcome of the disease.

MATERIALS AND METHODS

A total of 100 patients with acute pancreatitis were included in the prospective cohort study. Observed patients were divided into two groups according to their mean values of IAP (normal IAP values and elevated IAP values), which were compared with examined variables. Patients with intra-abdominal hypertension (IAH) were divided into four groups by IAP values, and those groups of patients were also compared with the examined variables.

RESULTS

Differences between body mass index (BMI) (p = 0.001), lactates (p = 0.006), and the Sequential Organ Failure Assessment (SOFA) score (p = 0.001) were statistically significant within all examined IAH groups. Differences between the mean arterial pressure (MAP) (p = 0.012) and filtration gradient (FG) (p < 0.001) were statistically significant between the first and second IAH groups in relation to the fourth. Differences in diuresis per hour (p = 0.022) showed statistical significance in relation to the first and third groups of IAH patients.

CONCLUSIONS

Changes in IAP values lead to changes in basic vital parameters MAP, APP, FG, diuresis per hour, and lactate levels in patients with acute pancreatitis. Early recognition of changes in the SOFA score accompanying an increase in the IAP value is essential.

Low intra-abdominal pressure in laparoscopic surgery: a systematic review and meta-analysis

BACKGROUND

Guidelines do not provide clear recommendations with regard to the use of low intra-abdominal pressure (IAP) during laparoscopic surgery. The aim of this meta-analysis is to assess the influence of low versus standard IAP during laparoscopic surgery on the key-outcomes in perioperative medicine as defined by the StEP-COMPAC consensus group.

MATERIALS AND METHODS

We searched the Cochrane Library, PubMed, and EMBASE for randomized controlled trials comparing low IAP (<10 mmHg) with standard IAP (10 mmHg or higher) during laparoscopic surgery without time, language, or blinding restrictions. According to the PRISMA guidelines, two review authors independently identified trials and extracted data. Risk ratio (RR), and mean difference (MD), with 95% CIs were calculated using random-effects models with RevMan5. Main outcomes were based on StEP-COMPAC recommendations, and included postoperative complications, postoperative pain, postoperative nausea and vomiting (PONV) scores, and length of hospital stay.

RESULTS

Eighty-five studies in a wide range of laparoscopic procedures (7349 patients) were included in this meta-analysis. The available evidence indicates that the use of low IAP (<10 mmHg) leads to a lower incidence of mild (Clavien-Dindo grade 1-2) postoperative complications (RR=0.68, 95% CI: 0.53-0.86), lower pain scores (MD=-0.68, 95% CI: -0.82 to 0.54) and PONV incidence (RR=0.67, 95% CI: 0.51-0.88), and a reduced length of hospital stay (MD=-0.29, 95% CI: -0.46 to 0.11). Low IAP did not increase the risk of intraoperative complications (RR=1.15, 95% CI: 0.77-1.73).

CONCLUSIONS

Given the established safety and the reduced incidence of mild postoperative complications, lower pain scores, reduced incidence of PONV, and shorter length of stay, the available evidence supports a moderate to strong recommendation (1a level of evidence) in favor of low IAP during laparoscopic surgery.

Hands off Trans-Femoral Venous Intra-Abdominal Pressure Estimates in Children: Results of a Sobering Single-Center Study

BACKGROUND

For a long time, trans-femoral venous pressure (FVP) measurement was considered a simple alternative for estimating intra-abdominal pressure (IAP). Since intravesical [IVP] and intragastric [IGP] pressure measurements are sometimes contraindicated for anatomical and pathophysiological reasons, FVP raised hopes, especially among pediatricians. Pediatric FVP validation studies have never been published; recent results from adult studies cast doubt on their interchangeability. Therefore, we compared for the first time the measurement agreement between FVP and IVP and IGP in children.

MATERIAL AND METHODS

We prospectively compared FVP with IVP and IGP, according to the Abdominal Compartment Society validation criteria. Additionally, we analyzed the agreement as a function of IAP or right heart valve regurgitation and pulmonary hypertension.

RESULTS

In a real-life PICU study design, n = 39 children were included (median age 4.8 y, LOS-PICU 23 days, PRISM III score 11). In n = 660 FVP-IGP measurement pairs, the median IAP was 7 (range 1 to 23) mmHg; in n = 459 FVP-IVP measurement pairs, the median IAP was 6 (range 1to 16) mmHg. The measurement agreement was extremely low with both established methods (FVP-IGP: r² 0.13, mean bias -0.8 ± 4.4 mmHg, limits of agreement (LOA) -9.6/+8.0, percentage error (PE) 55%; FVP-IVP: r² 0.14, bias +0.5 ± 4.2 mmHg, limit of agreement (LOA) -7.9/+8.9, percentage error (PE) 51%). No effect of the a priori defined influencing factors on the measurement agreement could be demonstrated.

CONCLUSIONS

In a study cohort with a high proportion of critically ill children suffering from IAH, FVP did not agree reliably with either IVP or IGP. Its clinical use in critically ill children must therefore be strongly discouraged.

Analysis of Incidence, Risk Factors and Outcomes Associated With Abdominal Hypertension in Major Burn Patients

The objective of this study is to analyze incidence and risk factors for intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) in major burn patients. Aprospective cohort study was conducted at a Burns Treatment Center, including all patients with a burned body surface area ≥20% admitted from August 2015 to January 2018. Intra-abdominal pressure was measured periodically during the first week of ICU stay. Sixty-four patients were analyzed, with median age of 39 years (interquartile range ITQ: 28-53) and 66% were male. Median burned body surface area was 30% (ITQ: 20-46). Twenty-eight (56%) patients presented criteria for IAH and seven (14%) developed clinical signs compatible with ACS. Burn severity was greater in the group that developed IAH, represented by the ABSI score. This group also presented higher values of creatinine and positive fluid balance. The group of patients with ACS showed a higher frequency of alterations in renal and respiratory functions. The organ systems most frequently affected in groups with diagnostic criteria for IAH and ACS were renal, cardiovascular and respiratory. Mortality rate at hospital outcome was 56%. In conclusion, the incidence of IAH during the study period was high in patients with extensive burns. The occurrence of ACS was associated with organic dysfunctions of the respiratory, cardiovascular and renal systems. The factors associated with intra-abdominal hypertension were age, extension of burned body surface, inhalation injury, and need for mechanical ventilation.

Intra-abdominal hypertension among medical septic patients associated with worsening kidney outcomes (IAH-WK study)

High intra-abdominal pressure (IAP) is associated with acute kidney injury (AKI). However, the relationship between intra-abdominal hypertension (IAH) and AKI in medical septic patients is still inconclusive. This prospective cohort study enrolled patients admitted in the Medical Intensive Care Unit from April 2020 to February 2021. Demographic, therapeutic, and laboratory data were obtained upon admission. The evaluation of IAP was performed via the intra-vesical method during the first and second 24 hours of admission. Kidney function was evaluated on the first 3 days and at least on the 7th day of enrollment. Among 79 patients, 30 (38%) developed IAH, while 50 (63.3%) developed AKI within 7 days. On the first day, the mean IAP was 15.4 (interquartile range [IQR], 4) and 7.0 (IQR, 3.7) mm Hg in the IAH and non-IAH groups, respectively. A total of 52 patients (65.8%) developed the primary outcome (i.e., a composite outcome including AKI, treatment with kidney replacement therapy, or death). On Cox proportional-hazards model between IAH and outcomes, after adjustment for multiple covariates, IAH was associated with a composite outcome (hazard ratio [HR], 6.5; 95% confidence interval [CI], 2.3-18.6; P < .005) and the development of AKI (HR, 6.5; 95% CI, 2.3-18.8; P < .005). IAH was associated with a composite outcome of AKI, treatment with kidney replacement therapy, or death in medical septic patients. thaiclinicaltrial.org, Identifier: TCTR20200531001, Registered May 24, 2020.

Impact of Obesity on Clinical Outcomes of Patients with Intra-Abdominal Hypertension and Abdominal Compartment Syndrome

Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are associated with high morbidity and mortality. Obesity may result in increased intra-abdominal pressure (IAP) and affect clinical outcomes of patients with IAH and/or ACS. This study aims to establish the impact of obesity on the clinical outcomes of IAH and ACS patients. A systematic search of Medline, Embase, and Scopus was performed in August 2022. Nine studies comprising 9938 patients were included. There were 65.1% males (n = 6250/9596). Patient demographics, comorbidities, and morbidities were analyzed in correlation with obesity and IAP. Obese patients had a higher risk of IAH (OR 8.5, p < 0.001). Obesity was associated with the need for renal replacement therapy, intensive care unit-acquired infections, systemic inflammatory response syndrome, acute respiratory distress syndrome, length of hospital stay, and mortality. This review highlights the lacunae in the existing literature to underpin the direct impact of obesity, independent of obesity-associated comorbidities, on the clinical outcomes of IAH and ACS.

The comorbidities of recurrent inguinal hernia in children: A systematic review

BACKGROUND

Higher risk of recurrence has been reported in pediatric inguinal hernia patients with specific comorbidities. The purpose of this systematic review was to investigate which comorbidities predispose to recurrent pediatric inguinal hernias (RPIHs).

METHODS

A comprehensive search of six databases was performed, reviewing the literature to date on RPIHs and the co-occurrence of comorbidities. English-language publications were considered for inclusion. The primary surgical technique (e.g., Potts procedure or laparoscopic repair) was not considered.

RESULTS

Fourteen articles published between 1967 and 2021 fulfilled the inclusion criteria and did not meet the exclusion criteria. They reported a total of 86 patients diagnosed with RPIHs with 99 comorbidities. Thirty-six percent of patients had conditions with increased intra-abdominal pressure, such as ventriculoperitoneal shunt for hydrocephalus, posterior urethral valves, bladder exstrophy, seizure disorder, asthma, using continuous positive airway pressure for respiratory distress syndrome, and gastroesophageal reflux disease. Twenty-eight percent of patients had diseases with weakness of the anterior abdominal wall, specifically mucopolysaccharidosis, giant omphalocele, Ehlers-Danlos syndrome, connective-tissue disorders, and segmental spinal dysgenesis.

CONCLUSIONS

The main comorbidities of RPIHs were conditions with increased intra-abdominal pressure and weakness of the anterior abdominal wall. Although these comorbidities are rare, the risk of recurrence must be noted.

Physicians' Knowledge of Abdominal Compartment Syndrome and Intra-Abdominal Hypertension in Saudi Arabia: An Online Cross-Sectional Survey Study

Objective

To determine physicians' knowledge of abdominal compartment syndrome and intra-abdominal hypertension in Saudi Arabia.

Methods

A cross-sectional online survey study was conducted on physicians in Saudi Arabia between March and August 2022. A previously developed questionnaire was adapted and used in this study. The survey instrument investigated the knowledge and management of intra-abdominal hypertension and abdominal compartment syndrome among physicians. Logistic regression was used to identify predictors of being knowledgeable about abdominal compartment syndrome and intra-abdominal hypertension.

Results

A total of 266 physicians participated in this study. Around one-fifth (21.8%) the study participants were ICU physicians and 25.0% reported that they practice internal medicine. Intra-abdominal hypertension (IAH) and the impact of increased intra-abdominal pressure (IAP) on organ function were terms that the majority of research participants (70.3%) reported they were familiar with. A similar percentage (73.7%) reported that they are familiar with abdominal compartment syndrome (ACS). Around 43.0% of the study participants reported that they do not know how to measure IAP. The most frequently reported (13.5%) intervention in the treatment of IAH and ACS was the use of inotropes or vasopressors. The study participants showed a weak level of knowledge of ACS and IAH with a median score of 3.00 (IQR: 5.00-2.00), which represents 27.3% of the maximum attainable score. Physicians working at hospitals with 20-50 ICU beds were 41.0% (odds ratio: 0.59 (CI: 0.37-0.96)) less likely to be knowledgeable about intra-abdominal hypertension and abdominal compartment syndrome (p≤0.05).

Conclusion

Physicians demonstrated a low level of IAP and ACS knowledge. To increase the safety of medical practices and enhance clinical outcomes for patients, awareness should be raised about the proper diagnosis and management of IAP and ACS. Future research should focus on developing effective educational strategies to improve physicians' understanding of IAP and ACS.

Low Intra-Abdominal Pressure with Complete Neuromuscular Blockage Reduces Post-Operative Complications in Major Laparoscopic Urologic Surgery: A before-after Study

Most urological interventions are now performed with minimally invasive surgery techniques such as laparoscopic surgery. Combining ERAS protocols with minimally invasive surgery techniques may be the best option to reduce hospital length-of-stay and post-operative complications. We designed this study to test the hypothesis that using low intra-abdominal pressures (IAP) during laparoscopy may reduce post-operative complications, especially those related to reduced intra-operative splanchnic perfusion or increased splanchnic congestion. We applied a complete neuromuscular blockade (NMB) to maintain an optimal space and surgical view. We compared 115 patients treated with standard IAP and moderate NMB with 148 patients treated with low IAP and complete NMB undergoing major urologic surgery. Low IAP in combination with complete NMB was associated with fewer total post-operative complications than standard IAP with moderate NMB (22.3% vs. 41.2%, p < 0.001), with a reduction in all medical post-operative complications (17 vs. 34, p < 0.001). The post-operative complications mostly reduced were acute kidney injury (15.5% vs. 30.4%, p = 0.004), anemia (6.8% vs. 16.5%, p = 0.049) and reoperation (2% vs. 7.8%, p = 0.035). The intra-operative management of laparoscopic interventions for major urologic surgeries with low IAP and complete NMB is feasible without hindering surgical conditions and might reduce most medical post-operative complications.

A Retrospective, Observational Study of Catheter-Associated Urinary Tract Infection Events Post-Implementation of a Novel Urinary Catheter System with Active Drain Line Clearance and Automated Intra-Abdominal Pressure Monitoring

Objective: A quality improvement study to assess catheter-associated urinary tract infection (CAUTI) rate post-implementation of a bladder catheter with integrated active drain line urine clearance and automated intra-abdominal pressure monitoring in a burn intensive care unit (ICU). DESIGN: Eight-year retrospective before and after study (2015−2022). Setting: A single American Burn Association-verified Burn Center with 14 inpatient beds. Patients: Patients meeting criteria for admission to a Burn Center. Methods: Retrospective cohort study following the implementation of a novel urine output monitoring system with integrated drain line and urine clearance. Data from a 48-month (from January 2015−December 2018) historical control (period 1) were compared to data from a 28-month (from January 2020 to April 2022) post-implementation period (period 2). Pre- and post-implementation CAUTI event incidences were compared. Patients were transferred from outside hospitals with gravity bladder. A distinction in the chart between catheter types was impossible. Charts were reviewed to characterize patients with CAUTI events. Results: A total of 42 CAUTIs in 2243 patients were identified using the National Health and Safety Network (NHSN) definition during the analyzed period. There were 40 CAUTI events in period 1 and two CAUTIs in period 2. The incidence of CAUTI events pre-implementation was 0.030 (mean of 10 CAUTI events per year) compared to 0.002 (mean of 1 CAUTI event per year) post-implementation of an automatic drain line clearing UO monitoring system showing a significant reduction in CAUTI events (p < 0.01, risk ratio novel vs. gravity bladder catheter 0.071, 95% confidence interval: 0.017−0.294). Conclusions: CAUTIs were reduced in the period following the implementation of a novel urinary catheter system with an integrated active drain line and urine clearance in burn patients.

Effect of Increased Intra-abdominal Pressure on the Esophagogastric Junction: A Systematic Review

With the advent of high-resolution esophageal manometry, it is recognized that the antireflux barrier receives a contribution from both the lower esophageal sphincter (intrinsic sphincter) and the muscle of the crural diaphragm (extrinsic sphincter). Further, an increased intra-abdominal pressure is a major force responsible for an adaptive response of a competent sphincter or the disruption of the esophagogastric junction resulting in gastroesophageal reflux, especially in the presence of a hiatal hernia. This review describes how the pressure dynamics in the lower esophageal sphincter were discovered and measured over time and how this has influenced the development of antireflux surgery.

High intra-abdominal pressure during hyperthermic intraperitoneal chemotherapy (HIPEC) following cytoreductive surgery (CRS) for peritoneal surface malignancies

OBJECTIVE

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) represent a mainstay of treatment for peritoneal malignancies. There is evidence that HIPEC using high intra-abdominal pressure (IAP) results in increased tissue penetration, although its safety profile remains relatively unknown. We thus aim to evaluate differences in intra- and post-operative outcomes in patients undergoing CRS-HIPEC with different levels of IAP.

METHODS

This pilot prospective cohort study was conducted from January 2020 to February 2021 with patients undergoing CRS-HIPEC. Low IAP during HIPEC was defined as <18 mmHg and high IAP as ≥18 mmHg. Data was collected on patient and tumor characteristics, intra-operative clinical and biochemical parameters, and immediate post-operative outcomes.

RESULTS

40 patients underwent CRS-HIPEC (n low = 20, n high = 20). Median IAP in the low and high IAP groups were 12.0 and 19.0 mmHg respectively. During HIPEC, both groups experienced increase in heart rate, central venous pressure, end tidal CO2, temperature, and serum glucose, with decrease in mean arterial pressure and base excess. There were no significant differences in hemodynamics between the 2 groups. Mild electrolyte derangements and a decrease in hemoglobin were noted in the high IAP group but were of small magnitude. Post-operatively, high IAP did not result in increased rate of complications, time to full feeds, ICU or total hospital stay.

CONCLUSIONS

High IAP in HIPEC is well tolerated and did not result in additional adverse events.

Pre-Clinical Validation of A Novel Continuous Intra-Abdominal Pressure Measurement Equipment (SERENNO)

Introduction: Increased intra-abdominal pressure (IAP) has an important impact on morbidity and mortality in critically ill patients. The SERENNO Sentinel system (Serenno Medical, Yokne’am Illit, Israel) is a novel device that allows automatic and continuous IAP measurements. Aims: Pre-clinical validation in a bench model study comparing the new device with the gold standard method and two other continuous IAP measurement devices. Methods: IAP measurement with the novel SERENNO device (IAP_SER) was compared with the gold standard IAP_H2O (water column height) and two other automatic and continuous IAP measurement devices: IAP_CiM measured via the CiMON device (Pulsion Medical Systems, Munich, Germany) and IAP_SPIE measured using the Spiegelberg device (Spiegelberg, Hamburg, Germany), which previously received the CE mark for clinical applications. The IAP measurement was performed six times (n = 6) at each pressure value (between 0 and 35 mmHg) with different methods and the height of the water column in a bench-top phantom was used as the reference IAP for further interpretations. In addition to the quadruple comparisons, intra- and inter-observer variability of IAP measurements were also calculated. Correlation studies and Bland and Altman’s analyses were performed in addition to the concordance study. Results: The CiMON and Spiegelberg devices showed a greater dynamic range and standard deviation when recording IAP_CiM and IAP_SPIE compared with IAP_SER. In general, the maximum and minimum values of IAP recorded with each device (at each level of IAP_H2O) were significantly different from each other. However, the average values were in very good agreement. The highest correlation was observed between IAP_SER and IAP_H2O, and IAP_SER and IAP_SPIE (R = 0.99, p = 0.001 for both comparisons and intra- and inter-observer measurements). Although the CiMON and SERENNO systems were in very good agreement with each other, a slightly smaller correlation coefficient was found between them (R = 0.95, p = 0.001, and R = 0.96, p = 0.001 for intra- and inter-observer measurements, respectively). When compared to the gold standard (IAP_H2O), Bland and Altman’s analysis showed a mean difference of +0.44, −0.25, and −0.04 mmHg for the intra-observer measurements and +0.18, −0.75, and −0.58 mmHg for the inter-observer measurements for IAP_SER, IAP_CiM, and IAP_SPIE, respectively. IAP_SER showed a small positive bias (overestimation), while IAP_CiM and IAP_SPIE showed a negative bias (underestimation) when compared to IAP_H2O. Further statistical analysis showed a concordance coefficient of 100% with an excellent ability of the SERENNO system in tracking IAP_H2O changes. Conclusions: Pre-clinical validation of a new IAP monitoring device (SERENNO) showed very promising results when compared with the gold standard and other continuous techniques; however, clinical trials should be followed as the next stage of the validation process. Based on the actual research guidelines, the SERENNO system can be used interchangeably with the gold standard.

[Comparison of intra-abdominal pressure, during spine surgeries, among two prone positional apparatuses in the same patient - a case report]

Spinal surgeries often require prone positioning of the patient. This is associated with increased intra-abdominal pressure, which may increase the risk of intra- and postoperative complications. The described case enables the comparison of two prone positional apparatuses and their influence on changes in intra-abdominal pressure during spine surgeries.

A CASE REPORT

A 74-year-old female patient underwent two spine surgeries due to a fracture of the Th12 vertebra and traumatic kyphosis. Both were performed in the prone position. During the first procedure, stabilization of the fracture, positioning was performed by placing the patient on the Allen table, whereas during the second procedure, laminectomy, by placing the patient on gel pads. During both surgeries the patient's intra-abdominal pressure was measured. The values measured while lying on the Allen table were found to be lower (mean 13.8 mmHg ± 0.66 mmHg) than the results obtained during the procedure utilizing gel pads (mean 24 mmHg ± 1.22 mmHg). Both surgeries were completed without complications. In both cases, creatinine, urea, and potassium concentrations as well as daily diuresis were measured to assess postoperative renal function. The results of these analyses did not indicate renal damage.

CONCLUSIONS

The way the patient is positioned on the abdomen has a significant impact on intra-abdominal pressure. Compared to gel pads, the Allen table allows for a reduction in abdominal pressure, which corresponds with lower values of intra-abdominal pressure. This may help reduce the risk of complications during surgeries performed in the prone position.

The Role of the Urinary Bladder in the Diagnosis of Abdominal Compartment Syndrome: A Prospective Study in Trauma Patients

Purpose The aim of this study was to evaluate the accuracy of bladder pressures in the diagnosis and management of abdominal compartment syndrome (ACS). Methods After Institutional Review Board (IRB) approval, nine operative abdominal trauma patients were prospectively studied over an 18-month period. Bladder pressures were compared to pressures obtained from intra-operatively placed electronic transducer located in the pelvis. Statistical analysis was performed using methods described by Bland and Altman. Results A Bland-Altman plot was used to assess the differences between bladder and transducer pressures. There was little agreement between the two methods at low (10-15 mmHg) and high (30-70 mmHg) pressures. At higher pressures, there was a notable difference between these two types of pressure. No patients required repeated operation. One patient died from severe traumatic brain injury. Conclusion Measurements obtained from the urinary bladder did not agree well with those obtained from within the peritoneal cavity. Furthermore, abdominal pressures greater than 20 mmHg did not show signs of ACS in this selected population, raising doubts about the utility of using abdominal pressures alone in the management of ACS.

Urinary catheter monitoring of intra-abdominal pressure after major abdominal surgery, a cost-benefit analysis

OBJECTIVE

To estimate costs and benefits associated with measurement of intra-abdominal pressure (IAP).

METHODS

We built a cost-benefit analysis from the hospital facility perspective and time horizon limited to hospitalization for patients undergoing major abdominal surgery for the intervention of urinary catheter monitoring of IAP. We used real-world data estimating the likelihood of intra-abdominal hypertension (IAH), abdominal compartment syndrome (ACS), and acute kidney injury (AKI) requiring renal replacement therapy (RRT). Costs included catheter costs (estimated $200), costs of additional intensive care unit (ICU) days from IAH and ACS, and costs of CRRT. We took the preventability of IAH/ACS given early detection from a trial of non-surgical interventions in IAH. We evaluated uncertainty through probabilistic sensitivity analysis and the effect of individual model parameters on the primary outcome of cost savings through one-way sensitivity analysis.

RESULTS

In the base case, urinary catheter monitoring of IAP in the perioperative period of major abdominal surgery had 81% fewer cases of IAH of any grade, 64% fewer cases of AKI, and 96% fewer cases of ACS. Patients had 1.5 fewer ICU days attributable to IAH (intervention 1.6 days vs. control of 3.1 days) and a total average cost reduction of $10,468 (intervention $10,809, controls $21,277). In Monte Carlo simulation, 86% of 1,000 replications were cost-saving, for a mean cost savings of $10,349 (95% UCI $8,978, $11,720) attributable to real-time urinary catheter monitoring of intra-abdominal pressure. One-way factor analysis showed the pre-test probability of IAH had the largest effect on cost savings and the intervention was cost-neutral at a prevention rate as low as 2%.

CONCLUSIONS

In a cost-benefit model using real-world data, the potential average in-hospital cost savings for urinary catheter monitoring of IAP for early detection and prevention of IAH, ACS, and AKI far exceed the cost of the catheter.

Abdominal Compartment Syndrome-When Is Surgical Decompression Needed?

Compartment syndrome occurs when increased pressure inside a closed anatomical space compromises tissue perfusion. The sudden increase in pressure inside these spaces requires rapid decompression by means of surgical intervention. In the case of abdominal compartment syndrome (ACS), surgical decompression consists of a laparostomy. The aim of this review is to identify the landmarks and indications for the appropriate moment to perform decompression laparotomy in patients with ACS based on available published data. A targeted literature review was conducted on indications for decompression laparotomy in ACS. The search was focused on three conditions characterized by a high ACS prevalence, namely acute pancreatitis, ruptured abdominal aortic aneurysm and severe burns. There is still a debate around the clinical characteristics which require surgical intervention in ACS. According to the limited data published from observational studies, laparotomy is usually performed when intra-abdominal pressure reaches values ranging from 25 to 36 mmHg on average in the case of acute pancreatitis. In cases of a ruptured abdominal aortic aneurysm, there is a higher urgency to perform decompression laparotomy for ACS due to the possibility of continuous hemorrhage. The most conflicting recommendations on whether surgical treatment should be delayed in favor of other non-surgical interventions come from studies involving patients with severe burns. The results of the review must be interpreted in the context of the limited available robust data from observational studies and clinical trials.

Effect of continuous hemofiltration on severe acute pancreatitis with different intra-abdominal pressure: A cohort study

BACKGROUND

The clinical efficacy and timing of continuous veno-venous hemofiltration (CVVH) in the treatment of severe acute pancreatitis (SAP) remain uncertain. In this prospective cohort study, patients with SAP were classified according to intra-abdominal pressure (IAP).

METHODS

Seventy-four patients with SAP admitted to the intensive care unit were randomly divided into group A (IAP ≥20 mm Hg) and group B (with IAP ≤20 mm Hg). Then, according to whether CVVH was administered or not, groups A and B were divided into 4 subgroups: group A1 and B1 (non-CVVH treatment), group A2 and B2 (CVVH treatment). Changes in clinical and laboratory indicators were recorded before and on the seventh day after treatment, and clinical outcomes were analyzed.

RESULTS

Before treatment, there was no significant difference in general conditions between subgroups A1 and A2, and between subgroups B1 and B2. After CVVH treatment, the indicators recorded in group A2 were significantly improved compared to those in group A1 (P < .05). In group A2, the 28 day operation rate was lower (P < .05), as mechanical ventilation, gastric decompression, and intensive care unit treatment time were shorter (P < .05). However, there was no statistically significant difference in any of the above indicators between subgroups B (P > .05). Groups A2 and B2 had more days of negative fluid balance within 1 week of admission than groups A1 and B1 (P < .05).

CONCLUSIONS

For SAP, patients with IAP ≥20 mm Hg can benefit from treatment with CVVH, but for patients with IAP ≤20 mm Hg, the efficacy is not clear, and monitoring IAP may be an indicator to decide whether or when to initiate CVVH. Negative fluid balance caused by CVVH treatment may be one of the reasons for the benefit of this group of patients.

Intra-abdominal hypertension and abdominal compartment syndrome in critically ill patients: A narrative review of past, present, and future steps

BACKGROUND AND OBJECTIVE

Intra-abdominal hypertension is frequently present in critically ill patients and is an independent predictor for mortality. In this narrative review, we aim to provide a comprehensive overview of current insights into intra-abdominal pressure monitoring, intra-abdominal hypertension, and abdominal compartment syndrome. The focus of this review is on the pathophysiology, risk factors and outcome of intra-abdominal hypertension and abdominal compartment syndrome, and on therapeutic strategies, such as non-operative management, surgical decompression, and management of the open abdomen. Finally, future steps are discussed, including propositions of what a future guideline should focus on.

CONCLUSIONS

Pathological intra-abdominal pressure is a continuum ranging from mild intra-abdominal pressure elevation without clinically significant adverse effects to substantial increase in intra-abdominal pressure with serious consequences to all organ systems. Intra-abdominal pressure monitoring should be performed in all patients at risk of intra-abdominal hypertension. Although continuous intra-abdominal pressure monitoring is feasible, this is currently not standard practice. There are a number of effective non-operative medical interventions that may be performed early in the patient's course to reduce intra-abdominal pressure and decrease the need for surgical decompression. Abdominal decompression can be life-saving when abdominal compartment syndrome is refractory to non-operative treatment and should be performed expeditiously. The objectives of open abdomen management are to prevent fistula and to achieve delayed fascial closure at the earliest possible time. There is still a lot to learn and change. The 2013 World Society of Abdominal Compartment Syndrome guidelines should be updated and multicentre studies should evaluate the effect of intra-abdominal hypertension treatment on patient outcome.

Non-Invasive Intra-Abdominal Pressure Measurement by Means of Transient Radar Method: In Vitro Validation of a Novel Radar-Based Sensor

Intra-abdominal hypertension, defined as an intra-abdominal pressure (IAP) equal to or above 12 mmHg is one of the major risk-factors for increased morbidity (organ failure) and mortality in critically ill patients. Therefore, IAP monitoring is highly recommended in intensive care unit (ICU) patients to predict development of abdominal compartment syndrome and to provide a better care for patients hospitalized in the ICU. The IAP measurement through the bladder is the actual reference standard advocated by the abdominal compartment society; however, this measurement technique is cumbersome, non-continuous, and carries a potential risk for urinary tract infections and urethral injury. Using microwave reflectometry has been proposed as one of the most promising IAP measurement alternatives. In this study, a novel radar-based method known as transient radar method (TRM) has been used to monitor the IAP in an in vitro model with an advanced abdominal wall phantom. In the second part of the study, further regression analyses have been done to calibrate the TRM system and measure the absolute value of IAP. A correlation of –0.97 with a p-value of 0.0001 was found between the IAP and the reflection response of the abdominal wall phantom. Additionally, a quadratic relation with a bias of −0.06 mmHg was found between IAP obtained from the TRM technique and the IAP values recorded by a pressure gauge. This study showed a promising future for further developing the TRM technique to use it in clinical monitoring.

Role of intra-abdominal pressure in the outcomes of perforation peritonitis: A prospective observational study

OBJECTIVES

Intra-abdominal pressure (IAP) has been investigated for its role in causing morbidity and mortality, with various studies showing different degrees of correlation. There remains paucity of literature on this subject, applied to patients of perforation peritonitis, especially in the Indian subcontinent.

MATERIAL AND METHODS

It is a prospective observational study involving 40 patients of perforation peritonitis undergoing exploratory laparotomy. IAP was measured as per WSACS (World Society of Abdominal Compartment Syndrome) guidelines. APACHE II (Acute Physiology And Chronic Health Evaluation- II) and SOFA (Sequential Organ Failure Assessment) were calculated. Data was collected regarding occurrence of prolonged ileus, burst abdomen, duration of hospital stay, 30 day mortality, and was statistically analyzed to correlate with IAP.

RESULTS

At admission, mean IAP was 13.37 mmHg, and the incidence of IAH was 65%. IAH was seen in 17.9% and 7.6% at 24 h and 48 h post-operatively. Incidence of prolonged ileus and burst abdomen were 7.7% and 22.5% respectively. Mortality rate was 17.5%. Mean duration of hospital stay was 13.45 days. Post-operative IAP correlated with mortality (p: 0.014) and post-operative SOFA score (p <0.05). Statistically significant correlation was also seen with the occurrence of prolonged ileus (p: 0.006). IAP did not significantly correlate with APACHE II score, occurrence of burst abdomen, and duration of hospital stay.

CONCLUSION

Rise in IAP correlates with deterioration of SOFA score, and also with the occurrence of prolonged ileus. IAP is also a predictor of mortality. IAP measured post-operatively (24 and 48 hours) had a better correlation with these outcomes than the value measured at admission. No statistically significant correlation of IAP with the occurrence of burst abdomen and duration of hospital stay could be found, which warrants further studies with a larger population.

Intra-abdominal hypertension and increased acute kidney injury risk: a systematic review and meta-analysis

OBJECTIVE

The present meta-analysis aimed to determine the relationship between intra-abdominal hypertension (IAH) and an increased prevalence of acute kidney injury (AKI) and identify the associated risk factors in various patient populations, regardless of whether they were admitted to an intensive care unit.

METHODS

We used three databases for the following search terms: "IAH," "abdominal compartment syndrome," "AKI," "acute kidney failure," and others. The articles retrieved were compared to identify appropriate studies published until 7 May 2020. The main outcome was AKI.

RESULTS

Six studies with 344 individuals were included. The patients were divided into two main groups: the IAH and non-IAH groups. Compared with patients without IAH, patients with IAH had a higher risk of AKI (odds ratio = 2.57, 95% confidence interval: 1.55-4.26). In the subgroup and meta-regression analyses, body mass index, age, the presence or absence of burns, and cardiac surgery did not affect the risk of AKI.

CONCLUSION

IAH was associated with AKI risk, and this association was not influenced by age, body mass index, the presence or absence of burns, or cardiac surgery.

Effect of intra-abdominal hypertension on the intraocular pressure of the conscious dogs

This study was performed to evaluate the effect of intra-abdominal pressure (IAP) on intraocular pressure (IOP) in conscious dog models using a balloon technique to generate intra-abdominal hypertension. Six healthy dogs without ocular abnormalities were evaluated in this study. A balloon device was placed in the intra-abdominal cavity. The abdomen was insufflated to IAP levels of 15 and 25 mmHg using the balloon device. Intraocular pressure was measured at baseline, at IAP levels of 15 and 25 mmHg, and after decompression. In comparison with the mean baseline IOP (15.1 ± 2.0 mmHg), there was a significant increase in IOP at IAP levels of 15 mmHg (20.0 ± 2.1 mmHg) and 25 mmHg (19.9 ± 2.2 mmHg), corresponding to a 32.4% and 31.7% increase from baseline IOP, respectively. The mean IOP after decompression (14.8 ± 1.7 mmHg) was significantly lower compared to those at IAP levels of 15 and 25 mmHg. The present findings demonstrate that increased IAP has a clinically significant effect on IOP in dogs under conscious conditions. Although more research is needed to determine of increased IAP on IOP, these findings suggest that increased IAP leads to mild and reversible increase in IOP.

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

Objective

This 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.

Methods

Critically 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.

Results

A 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.

Conclusion

There 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.

The Nature of Recruitment and De-Recruitment and Its Implications for Management of ARDS

Recruitment maneuvers in ARDS are used to improve oxygenation and lung mechanics by applying high airway pressures to reopen collapsed or obstructed peripheral airways and alveoli. In the early 1990s, recruitment maneuvers became a central feature of a variant form of lung-protective ventilation known as open-lung ventilation. This strategy is based on the belief that repetitive opening and closing of distal airspaces induces shear injury and therefore contributes both to ventilator-induced lung injury and ARDS-associated mortality. However, the largest multi-center randomized controlled trial of open-lung ventilation in moderate to severe ARDS reported that recruitment maneuver plateau pressures of 50-60 cm H₂O were associated with significantly higher mortality compared to traditional lung-protective ventilation. Despite being based on well conducted preclinical and clinical recruitment maneuver studies, the higher mortality associated with the open-lung ventilation strategy requires re-examining the assumptions and conclusions drawn from those previous studies. This narrative review examines the evidence used to design recruitment maneuver strategies. We also review the radiologic, rheologic, and histopathologic evidence regarding the nature of lung injury and the phenomena of recruitment and de-recruitment as it informs our perceptions of recruitment potential in ARDS. Major lung-protective ventilation clinical trial data and other clinical data are also examined to assess the practical necessity of recruitment maneuvers in ARDS and whether a subset of cases might benefit from pursuing recruitment maneuver therapy. Finally, a less a radical approach to recruitment maneuvers is offered that might achieve the goals of recruitment maneuvers with less risk of harm.

An assessment of techniques and practices used to elevate intra-abdominal pressure when assessing pelvic floor dysfunction

AIMS

To determine terminology and methods for raising intra-abdominal pressure (IAP) currently used by clinicians to assess pelvic floor dysfunction (PFD) and to measure the effect of these maneuvers on IAP.

METHODS

Three-hundred questionnaires were distributed at two scientific meetings in the United Kingdom to determine methods clinicians used to raise IAP and their perceptions of these methods. Twenty healthy volunteers were also recruited to measure the effect of two methods of raising IAP: Valsalva maneuver (VM) and bear down maneuver (BDM). IAP pressure was measured with rectal catheters connected to pressure sensors. The IAP was measured during each maneuver in both standing and supine positions.

RESULTS

Maneuvers used in practice were cough (79%), BDM (60%), and VM (38%). 44% of clinicians felt patients found it difficult to raise their IAP. There was uncertainty among clinicians as to which method was the most effective in raising IAP and whether the different methods produced the same rise in IAP. On testing IAP in 20 healthy volunteers, median (interquartile range) IAP generated during BDM; 101 (59.1) cmH₂ O was significantly higher than that generated during VM; 80.3 (43.6) cmH₂ O (p < .0001).

CONCLUSION

Clinicians varied widely in the maneuvers they used to raise patients' IAP to test for PFD and there was uncertainty about the maneuvers' effect on IAP. In healthy volunteers, BDM produced significantly higher IAP than VM. We recommend standardization of terminology and techniques used to raise IAP when assessing PFD, to ensure consistency of diagnosis and assessment of treatment outcomes.

Repair of a Giant Inguinal Hernia

We report a case of a giant inguinal hernia (GIH) that underwent open surgical repair with mesh. The patient had a massive transcompartmental redistribution of abdominal contents from the abdominopelvic cavity to the hernia sac in the scrotum, with subsequent effects on the mechanical nature of the abdominal wall muscles. Repair of this type of giant hernia is challenging as it can raise the intra-abdominal pressure, therefore increasing the risk of abdominal compartment syndrome (ACS). The large size and chronicity of the hernia, associated with deranged mechanical forces/properties of the abdominal wall, made the management of this complex case unique and interesting. In similar cases of massive incisional or ventral hernias, the term “loss of domain” (LOD) is used. In such types of massive hernias, it is important to carefully plan and monitor for adverse physiological effects associated with increased abdominal pressure.

Prevalence of intra-abdominal hypertension in horses with colic

OBJECTIVE

To determine an abdominal pressure cutoff value for intra-abdominal hypertension (IAH) in the horse and characterize IAH in horses with acute colic.

DESIGN

Prospective clinical cohort.

SETTING

University teaching hospital.

ANIMALS

Nine healthy adult horses and 56 horses with acute colic.

INTERVENTIONS

Ventral intra-abdominal pressure (IAP) was measured in triplicate at end expiration and averaged. Each colic case was classified as medical or surgical and large intestine (LI) or small intestine (SI). Management and final outcome (alive, euthanized, or died) were recorded. IAH was defined as ≥32 mm Hg (mean + 2 SDs of ventral IAP in control horses). Proportions of horses with and without IAH for different lesions were expressed as fractions and percentages. Differences in IAP between groups were determined using ANOVA with post-testing or t-tests. Odds ratio for management strategy (ie, need for medical or surgical) in horses with IAH was performed using Fisher's exact test. P < 0.05 was considered significant.

MEASUREMENTS AND MAIN RESULTS

IAP was higher in horses with colic compared to controls (P = 0.025). Over 18 months, 30.4% of horses with colic had IAH (n = 10 LI lesions, n = 7 SI lesions). Horses with LI medical lesions had the highest IAP of all lesions (mean 36.5 mm Hg). IAH horses with medical lesions were 15 times more likely to survive than IAH horses requiring surgery (P = 0.03).

CONCLUSIONS

Acute colic in horses is associated with an increased ventral IAP compared with healthy controls. IAH does exist in horses with colic, notably LI medical lesions, and is associated with nonsurvival in horses that require surgery.

Polycompartment syndrome - intra-abdominal pressure measurement

Intra-abdominal hypertension and the abdominal compartment syndrome are well-known, serious, life-threatening clinical entities in acute care surgery. A common characteristic of these syndromes is the permanent and irreversible damage that may affect the organs which can be found inside the given compartment if quick intervention cannot be provided. All factors which may and can lead to a sudden increase in the intra-abdominal pressure can be found among the triggering factors of abdominal compartment syndrome. Despite the modern and quick diagnostics, and the adequate surgical interventions performed in time, the mortality of this syndrome is extremely high (38-71%). It affects practically all vital organ systems: cardiovascular, respiratory, urinary and central nervous system. There are four major compartments in the human body: the head, the chest, the abdomen and the extremities. When two or more compartments have elevated pressures the name of the clinical entity is polycompartment syndrome, first described in 2007. The only possible way of establishing the diagnosis is to measure the intra-abdominal pressure, a widespread manner of which is the measurement through the bladder. Treatment of abdominal and polycompartment syndrome is nearly always surgical decompression with temporary abdominal wall closure or open abdominal treatment. Clinicians need to be aware of the real existence of polycompartment syndrome and the complex and constant interplay of raised pressure between compartments. This highlights the importance of research and development of new intra-abdominal pressure measurement techniques.

Pressure-Volume Curve during Capnoperitoneum in Cats

Laparoscopy is a growing field in veterinary medicine, although guidelines are lacking. The objective of this study was to evaluate the pressure-volume curve during capnoperitoneum in cats. A total of 59 female cats were scheduled for routine laparoscopy. Pressure and volume data were recorded and processed, and the yield point of the curve was calculated using a method based on a capacitor discharging function. For the remaining 40 cats, a linear-like pressure-volume curve was observed until a yield point with a mean cutoff pressure (COP) of 6.44 ± 1.7 mmHg (SD) (range, 2.72-13.00 mmHg) and a mean cutoff volume (COV) of 387 ± 144.35 mL (SD) (range, 178.84-968.43 mL) was reached. The mean mL/kg CO₂ value in cats was 208 ± 34.69 mL/kg (range, 100.00-288.46 mL/kg). The COV correlated with COP and body weight but not with body condition score (BCS). COP correlated only with the COV. This study suggests that feline patients have a pressure-volume curve similar to that of canine patients, and the same pressure limit recommendations can be used for both species. After a yield point of 6.44 mmHg is reached, the increment in volume decreases exponentially as the intra-abdominal pressure (IAP) increases.

Preeclampsia Is a Syndrome with a Cascade of Pathophysiologic Events

This review integrates the currently available information on the molecular, cellular, and systemic mechanisms involved in the pathophysiology of preeclampsia. It highlights that the growth, protection, and promotion of the conceptus requires the modulation of an intact maternal immune system, communication between the mother and fetus, and adaptation of the maternal organic functions. A malfunction in any of these factors, on either side, will result in a failure of the cascade of events required for the normal course of pregnancy. Maladaptive processes, initially aiming to protect the conceptus, fail to anticipate the gradually increasing cardiovascular volume load during the course of pregnancy. As a result, multiple organ dysfunctions install progressively and eventually reach a state where mother and/or fetus are at risk of severe morbidity or even mortality, and where the termination of pregnancy becomes the least harmful solution. The helicopter view on pathophysiologic processes associated with preeclampsia, as presented in this paper, illustrates that the etiology of preeclampsia cannot be reduced to one single mechanism, but is to be considered a cascade of consecutive events, fundamentally not unique to pregnancy.

The Association Between Pelvic Floor Muscle Force and General Strength and Fitness in Postpartum Women

OBJECTIVE

The aim of the study was to determine whether measures of muscular strength and fitness are associated with pelvic floor muscle (PFM) force 1-year postpartum in a population of primiparous women who delivered vaginally.

METHODS

This cross-sectional analysis is an ancillary study to an ongoing prospective cohort study and includes 203 primiparous women. Procedures collected 1-year postpartum included maximal PFM force, grip strength, trunk flexor muscle endurance, percent body fat, intra-abdominal pressure during trunk flexor endurance testing, intra-abdominal pressure during strain, and self-reported physical activity.

RESULTS

The mean (SD) age was 29.8 (5.0) years and the mean (SD) body mass index was 24.5 (5.2) kg/m. Nineteen percent were of Hispanic ethnicity. The median (interquartile range) PFM force was 5.05 (2.86-7.94) N. The median (interquartile range) trunk flexor endurance time was 146.0 (78.0-267.0), whereas the mean (SD) grip strength and percent fat were 32.4 (6.4) kg and 29.4% (10.0), respectively.There were no statistically significant associations between PFM force and any of the measures tested on analyses unadjusted or adjusted for self-report of doing PFM exercises. Of other factors evaluated, non-Hispanic ethnicity, increasing age, self-reported family history of pelvic organ prolapse or urinary incontinence, and normal and obese body mass index (both compared with overweight) were associated with lower PFM force.

CONCLUSIONS

In primiparous women 1-year postpartum, we found no associations between PFM force and measures of strength and fitness. This study's results are consistent with existing literature that specific, targeted, and consistent pelvic floor exercises are the best way to improve PFM strength.

Alternative strategies for the management of ovarian hyperstimulation syndrome, the role of intra-abdominal hypertension control

The aim of this study is to analyze the methods for reducing intra-abdominal pressure (IAP) in the management of the moderate and severe forms of ovarian hyperstimulation syndrome (OHSS). We carried out a systematic review of the literature. An evaluation of clinical trials, meta-analysis, case-reports, and reviews assessing the management of conditions associated with OHSS and intra-abdominal hypertension (IAH)/abdominal compartment syndrome (ACS) was made using the following data sources: MEDLINE Pubmed (from 1966 to July 2019) and the Cochrane Controlled Clinical Trials Register, Embase (up to July 2019). The principles of treatment of IAH syndrome can be considered in the treatment of moderate and severe forms of OHSS. Medical treatment of patients with increased IAP in OHSS should be started early to prevent further organ dysfunction and avoid a transition to a more severe stage of IAH and ACS. Some of the new, non-surgical methods, such as continuous negative extra-abdominal pressure, are a promising option in specific groups of patients with OHSS. This review provides suggestions for the management of OHSS based on the principles of therapy for IAH syndrome. Further well-designed studies are needed to confirm these initial data.

Supine equilibration of extracellular fluid in peritoneal dialysis varies with intra-abdominal pressure

BACKGROUND

Increased intra-abdominal pressure (PIA) leads to venous congestion in splanchnic and adjoining circulations. The aim is to examine whether PIA in peritoneal dialysis (PD) affects the mobilization of extracellular fluid from the lower body in supine body position.

METHODS

Patients were studied during a regular peritoneal equilibration test (PET) in supine body position using multifrequency bioimpedance analysis to determine extracellular resistance and absolute volume overload (AVO) in wrist-to-ankle (W2A) as well as in ankle-to-ankle (A2A) configurations. Measurements were taken at baseline (T0) after draining the peritoneal cavity, at T1 shortly after filling with 2 L of standard dialysate, and at T2 before taking the 2 h PET samples. PIA was measured from the column height in the PD catheter. Extracellular resistance in the lower extremities (RL) was taken as half of the A2A resistance.

RESULTS

Eighteen patients (56 ± 15 years, 76 ± 21 kg, body mass index (BMI) 26.4 ± 7 kg/m², 13 men) were studied. After having assumed a supine body position for the duration of 17, 77, and 155 min, AVO continuously decreased from 1.6 ± 1.3 (T0) to 1.2 ± 1.5 (T1) and 1.0 ± 1.4 L (T2). RL significantly increased from 238 ± 57 (T0) to 254 ± 62 (T1) and 264 ± 67 Ohm (T2). This increase was negatively correlated to BMI and PIA measured at any time point, but not to net ultrafiltration volume.

CONCLUSIONS

Orthostatic fluid shifts from the lower limbs may take up to 2 h in supine PD patients, especially with high BMI and PIA because of venous congestion in splanchnic and adjoining circulations.