Effectiveness of vacuum-assisted wound closure and mesh-mediated fascial traction in open abdomen management.

PURPOSE: To determine the effectiveness of vacuum-assisted wound closure and mesh-mediated fascial traction (VAWCM) in patients undergoing open abdomen management (OAM). METHODS: Data from cases with OAM for at least five days who were admitted to our institution between January 2011 and December 2020 were included. We compared the patient's age, sex, medical history, indication for initial surgery, APACHE II scores, indication for OAM, operative time, intraoperative blood loss, intraoperative transfusion, success of primary fascial closure (rectus fascial closure and bilateral anterior rectus abdominis sheath turnover flap method), success of planned ventral hernia, duration of OAM, and in-hospital mortality between patients undergoing VAWCM (VAWCM cases, n = 27) and vacuum-assisted wound closure (VAWC) alone (VAWC cases, n = 25). RESULTS: VAWCM cases had a significantly higher success rate of primary fascial closure (70% vs. 36%, p = 0.030) and lower in-hospital mortality (26% vs. 72%, p = 0.002) than VAWC cases. A multivariate logistic regression analysis showed that VAWCM was an independent factor influencing in-hospital mortality (odds ratio, 0.14; 95% confidence interval: 0.04-0.53; p = 0.004). CONCLUSION: VAWCM is associated with an increased rate of successful primary fascial closure and may reduce in-hospital mortality.

Abdominal Compartment Syndrome Secondary to Bulimia Nervosa: A Case Report and Systematic Review of Published Cases.

BACKGROUND: Abdominal compartment syndrome (ACS) is typically attributed to critically unwell patients with trauma, burns, post surgery, and massive ascites. A rare but fatal cause of ACS is bulimia nervosa (BN), which is an eating disorder characterized by bingeing, followed by methods to avoid weight gain, including purging. CASE REPORT: We present a case of a 20-year-old woman who presented with abdominal pain and distension after consuming a large quantity of food the previous night and was unable to purge. She was initially managed conservatively and discharged home, but returned subsequently on the same day with clinical features of ACS secondary to acute gastric distension. Decompression resulted in life-threatening reperfusion injury with critical electrolyte abnormalities and fatal cardiac arrest in the operating theatre. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: A systematic review of the literature found only 11 case reports of ACS secondary to BN, of which only 6 patients survived due to early diagnosis and decompression. Inability to purge and lower limb ischemia appeared to be associated with increased mortality. As BN is a common emergency presentation, the case and systematic review highlights the need to consider ACS as a potentially life-threatening complication of binge eating, particularly when there is unsuccessful purging.

Ten good reasons to consider gastrointestinal function after acute brain injury.

The brain-gut axis represents a bidirectional communication linking brain function with the gastrointestinal (GI) system. This interaction comprises a top-down communication from the brain to the gut, and a bottom-up communication from the gut to the brain, including neural, endocrine, immune, and humoral signaling. Acute brain injury (ABI) can lead to systemic complications including GI dysfunction. Techniques for monitoring GI function are currently few, neglected, and many under investigation. The use of ultrasound could provide a measure of gastric emptying, bowel peristalsis, bowel diameter, bowel wall thickness and tissue perfusion. Despite novel biomarkers represent a limitation in clinical practice, intra-abdominal pressure (IAP) is easy-to-use and measurable at bedside. Increased IAP can be both cause and consequence of GI dysfunction, and it can influence cerebral perfusion pressure and intracranial pressure via physiological mechanisms. Here, we address ten good reasons to consider GI function in patients with ABI, highlighting the importance of its assessment in neurocritical care.

Differential Effects of Intra-Abdominal Hypertension and ARDS on Respiratory Mechanics in a Porcine Model.

Background and Objectives: Intra-abdominal hypertension (IAH) and acute respiratory distress syndrome (ARDS) are common concerns in intensive care unit patients with acute respiratory failure (ARF). Although both conditions lead to impairment of global respiratory parameters, their underlying mechanisms differ substantially. Therefore, a separate assessment of the different respiratory compartments should reveal differences in respiratory mechanics. Materials and Methods: We prospectively investigated alterations in lung and chest wall mechanics in 18 mechanically ventilated pigs exposed to varying levels of intra-abdominal pressures (IAP) and ARDS. The animals were divided into three groups: group A (IAP 10 mmHg, no ARDS), B (IAP 20 mmHg, no ARDS), and C (IAP 10 mmHg, with ARDS). Following induction of IAP (by inflating an intra-abdominal balloon) and ARDS (by saline lung lavage and injurious ventilation), respiratory mechanics were monitored for six hours. Statistical analysis was performed using one-way ANOVA to compare the alterations within each group. Results: After six hours of ventilation, end-expiratory lung volume (EELV) decreased across all groups, while airway and thoracic pressures increased. Significant differences were noted between group (B) and (C) regarding alterations in transpulmonary pressure (TPP) (2.7 ± 0.6 vs. 11.3 ± 2.1 cmH2O, p < 0.001), elastance of the lung (EL) (8.9 ± 1.9 vs. 29.9 ± 5.9 cmH2O/mL, p = 0.003), and elastance of the chest wall (ECW) (32.8 ± 3.2 vs. 4.4 ± 1.8 cmH2O/mL, p < 0.001). However, global respiratory parameters such as EELV/kg bodyweight (-6.1 ± 1.3 vs. -11.0 ± 2.5 mL/kg), driving pressure (12.5 ± 0.9 vs. 13.2 ± 2.3 cmH2O), and compliance of the respiratory system (-21.7 ± 2.8 vs. -19.5 ± 3.4 mL/cmH2O) did not show significant differences among the groups. Conclusions: Separate measurements of lung and chest wall mechanics in pigs with IAH or ARDS reveals significant differences in TPP, EL, and ECW, whereas global respiratory parameters do not differ significantly. Therefore, assessing the compartments of the respiratory system separately could aid in identifying the underlying cause of ARF.

Incidence and Mortality of Pediatric Abdominal Compartment Syndrome.

INTRODUCTION: Abdominal compartment syndrome (ACS) is the presence of intra-abdominal hypertension with systemic, multiorgan effects and is associated with high mortality, yet the national incidence and mortality rates of pediatric ACS remain unknown. The aim of this study is to evaluate the incidence and mortality of pediatric ACS over a 13-year period across multiple children's hospitals and between individual children's hospitals in the United States. METHODS: We performed a retrospective cohort study on children (aged < 18 y) with ACS in the Pediatric Health Information Systems database from 2007 to 2019. We identified ACS patients by International Classification of Diseases codes in the ninth and 10th revision. The primary outcomes were incidence and mortality, which were analyzed by year, age, and hospital of admission. RESULTS: Across 49 children's hospitals, we identified 2887 children with ACS from 2007 to 2019 in the Pediatric Health Information Systems database. The overall incidence of ACS was 0.17% and the overall mortality was 48.87%. There was no significant difference in annual incidence (P = 0.12) or mortality (P = 0.39) over the study period. There was no difference in incidence across age group (P = 0.38); however, mortality in patients 0-30 d old (58.61%) was significantly higher than older age groups (P < 0.0001). The hospital-specific incidence (0.04%-0.46%) and mortality (28.57%-71.43%) varied widely. CONCLUSIONS: The annual incidence and mortality of pediatric ACS are unchanged from 2007 to 2019. ACS mortality remains high, especially in neonatal intensive care unit patients. No obvious correlation is seen between incidence rates and mortality. Differing hospital-specific incidence and mortality could suggest inconsistencies between institutions that affect pediatric ACS care, perhaps with respect to recognition and diagnosis.

Supine transfer test-induced changes in cardiac index predict fluid responsiveness in patients without intra-abdominal hypertension.

BACKGROUND: The reversible maneuver that mimics the fluid challenge is a widely used test for evaluating volume responsiveness. However, passive leg raising (PLR) does have certain limitations. The aim of the study is to determine whether the supine transfer test could predict fluid responsiveness in adult patients with acute circulatory failure who do not have intra-abdominal hypertension, by measuring changes in cardiac index (CI). METHODS: Single-center, prospective clinical study in a 25-bed surgery intensive care unit at the Fudan University Shanghai Cancer Center. Thirty-four patients who presented with acute circulatory failure and were scheduled for fluid therapy. Every patient underwent supine transfer test and fluid challenge with 500 mL saline for 15-30 min. There were four sequential steps in the protocol: (1) baseline-1: a semi-recumbent position with the head of the bed raised to 45°; (2) supine transfer test: patients were transferred from the 45° semi-recumbent position to the strict supine position; (3) baseline-2: return to baseline-1 position; and (4) fluid challenge: administration of 500 mL saline for 15-30 min. Hemodynamic parameters were recorded at each step with arterial pulse contour analysis (ProAQT/Pulsioflex). A fluid responder was defined as an increase in CI ≥ 15% after fluid challenge. The receiver operating characteristic curve and gray zone were defined for CI. RESULTS: Seventeen patients were fluid challenge. The r value of the linear correlations was 0.73 between the supine transfer test- and fluid challenge-induced relative CI changes. The relative changes in CI induced by supine transfer in predicting fluid responsiveness had an area under the receiver operating characteristic curve of 0.88 (95% confidence interval 0.72-0.97) and predicted a fluid responder with 76.5% (95% confidence interval 50.1-93.2) sensitivity and 88.2% (95% confidence interval 63.6-98.5) specificity, at a best threshold of 5.5%. Nineteen (55%) patients were in the gray zone (CI ranging from -3 and 8 L/min/m2). CONCLUSION: The supine transfer test can potentially assist in detecting fluid responsiveness in patients with acute circulatory failure without intra-abdominal hypertension. Nevertheless, the small threshold and the 55% gray zone were noteworthy limitation. TRIAL REGISTRATION: Predicting fluid responsiveness with supine transition test (ChiCTR2200058264). Registered 2022-04-04 and last refreshed on 2023-03-26, https://www.chictr.org.cn/showproj.html?proj=166175 .

Elevation of the head of bed reduces splanchnic blood flow in patients with intra-abdominal hypertension.

BACKGROUND: Elevation of the head of bed (HOB) increases intra-abdominal pressure (IAP), but the effect of body position on abdominal splanchnic perfusion is not clear. The current study aimed to evaluate the effect of body position on the superior mesenteric artery (SMA) and the celiac artery (CA) blood flow by Doppler ultrasound in mechanically ventilated patients with intra-abdominal hypertension (IAH). METHODS: This prospective cohort study included 53 mechanically ventilated patients with IAH. IAP, hemodynamic variables, and Doppler parameters of the SMA and CA were measured in the supine position. The measurements were repeated after the HOB angle was raised to 15° for 5 min and similarly at HOB angles of 30° and 45°. Finally, the patient was returned to the supine and these variables were re-measured. RESULTS: The median (interquartile range, IQR) superior mesenteric artery blood flow (SMABF) decreased from 269 (244-322) to 204 (183-234) mL/min and the median (IQR) celiac artery blood flow (CABF) from 424 (368-483) to 376 (332-472) mL/min (both p<0.0001) while median (IQR) IAP increased from 14(13-16) to 16(14-18) mmHg (p<0.0001) when the HOB angle was changed from 0° to 15°. However, SMABF and CABF were maintained at similar levels from 15° to 30°, despite median (IQR) IAP increased to 17(15-18) mmHg (p = 0.0002). Elevation from 30° to 45° further reduced median (IQR) SMABF from 200(169-244) to 164(139-212) mL/min and CABF from 389(310-438) to 291(241-383) mL/min (both p<0.0001), Meanwhile, median (IQR) IAP increased to 19(18-21) mmHg (p<0.0001). CONCLUSIONS: In mechanically ventilated patients with IAH, progressive elevation of the HOB from a supine to semi-recumbent position was associated with a gradual reduction in splanchnic blood flow. However, the results indicate that splanchnic blood flow is not further reduced when the HOB is elevated from 15° to 30°.This study confirms the influence of head-up angle on blood flow of the splanchnic organs and may contribute to the selection of the optimal position in patients with abdominal hypertension.

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.

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

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

Feasibility analysis of a novel non-invasive ultrasonographic method for the measurement of intra-abdominal pressure in the intensive care unit.

Increased intra-abdominal pressure (IAP) is an important vital sign in critically ill patients and has a negative impact on morbidity and mortality. This study aimed to validate a novel non-invasive ultrasonographic approach to IAP measurement against the gold standard intra-bladder pressure (IBP) method. We conducted a prospective observational study in an adult medical ICU of a university hospital. IAP measurements using ultrasonography by two independent operators, with different experience levels (experienced, IAPUS1; inexperienced, IAPUS2), were compared with the gold standard IBP method performed by a third blinded operator. For the ultrasonographic method, decremental external pressure was applied on the anterior abdominal wall using a bottle filled with decreasing volumes of water. Ultrasonography looked at peritoneal rebound upon brisk withdrawal of the external pressure. The loss of peritoneal rebound was identified as the point where IAP was equal to or above the applied external pressure. Twenty-one patients underwent 74 IAP readings (range 2-15 mmHg). The number of readings per patient was 3.5 ± 2.5, and the abdominal wall thickness was 24.6 ± 13.1 mm. Bland and Altman's analysis showed a bias (0.39 and 0.61 mmHg) and precision (1.38 and 1.51 mmHg) for the comparison of IAPUS1 and IAPUS2 and vs. IBP, respectively with small limits of agreement that were in line with the research guidelines of the Abdominal Compartment Society (WSACS). Our novel ultrasound-based IAP method displayed good correlation and agreement between IAP and IBP at levels up to 15 mmHg and is an excellent solution for quick decision-making in critically ill patients.

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

BACKGROUND: Intra-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. METHODS: In 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. RESULTS: A 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. CONCLUSION: Neostigmine 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).

Are anthropometric data a tool for determining the severity of OHSS? Yes, it could be!

BACKGROUND: All management guidelines of ovarian hyperstimulation syndrome (OHSS) recommend daily monitoring of women's body weight, waist circumference and note that as indicators increase, the severity OHSS also increases. However, the dynamics of abdominal size and its relationship with markers of OHSS severity have not been highlighted. The purpose of this study is to assess the usefulness of various anthropometric indicators for determining the degree of OHSS severity as well as paracentesis indications. METHODS: Observational study including 76 women complaining with OHSS. Clinical history, physical examination, laboratory tests, and ultrasound measurement of the ovarian volume (OV) and ascites index (AsI) were done in all cases. Intra-abdominal pressure (IAP) was assessed using an intravesical manometer. The anteroposterior diameter of the abdomen (APD) and transverse diameter of the abdomen (TS) were measured with a pelvimeter. The APD/TS ratio was calculated. RESULTS: The APD/TS ratio increased progressively and tended to be the highest in the most symptomatic stage of OHSS (Kruskal-Wallis test, p < 0.001). The median APD/TS was significantly lower in patients with mild OHSS (0.55 [IQR, 0.44-0.64]) compared with severe OHSS (0.87 [IQR, 0.80-0.93]; p < 0.001) or critical OHSS (1.04 [IQR, 1.04-1.13]; p < 0.001). Similarly, the median APD/TS of the moderate OHSS group (0.65 [IQR, 0.61-0.70]) was significantly lower than that of the severe (p < 0.001) and critical OHSS group (p = 0.001). There was a strong positive correlation between APD/TS and IAP (Spearman's r = 0.886, p < 0.01). The APD/TS ratio showed a significant positive correlation with AsI (Spearman's r = 0.695, p < 0.01) and OV (Spearman's r = 0.622, p < 0.01). No significant differences were observed in age, height, weight, body mass index, hip circumference or waist circumference between moderate, severe and critical OHSS groups. CONCLUSIONS: The APD/TS ratio is related to the severity of OHSS. Monitoring APD/TS dynamics could be a method of indirectly controlling intra-abdominal volume, compliance of the abdominal wall and IAP. In conjunction with clinical and laboratory data, APD/TS might be an indicator for paracentesis.

Reconfiguration from veno-arterial to veno-arterio-venous extracorporeal membrane oxygenation for massive pulmonary embolism.

Differential hypoxia may occur after the initiation of femorofemoral veno-arterial extracorporeal membrane oxygenation (VA ECMO) if cardiac function improves while severe respiratory failure is still present, one of the most difficult problems encountered during VA ECMO. Reconfiguration to veno-arterio-venous ECMO (V-AV ECMO) is one of several methods of dealing with differential hypoxia. V-AV ECMO requires triple cannulation and careful management of the reinjection flow, but the risk of bleeding is lower than in a surgical procedure, such as central ECMO or a subclavian artery graft. Herein, we reported a patient with a massive pulmonary embolism who received VA ECMO, which was reconfigured to V-AV ECMO 3 days later when differential hypoxia occurred. A drainage cannula was newly inserted via the right internal jugular vein, and an existing drainage cannula was used for reinjection after repositioning it caudally. V-AV ECMO is an effective and feasible treatment for differential hypoxia despite the paucity of the procedure to date.

INTRABDOMINAL PRESSURE AND ITS CORRECTION IN ACUTE SURGICAL PATHOLOGY.

OBJECTIVE: The aim: Improving the results of treatment of patients with acute surgical pathology of the abdominal cavity by correcting intra-abdominal hypertension (IAH). PATIENTS AND METHODS: Materials and methods: The results of examination and treatment of 187 patients with acute surgical pathology, which was accompanied by elevation of IAP. To compare the results, depending on the chosen diagnostic and treatment tactics, patients were divided into two groups: comparison and main. The comparison group (85 people (45,5%) included patients who have been treated with traditional approaches in diagnosis and treatment according to existing treatment protocols. The main group (102 people (54,5%) included patients in whose treatment we additionally used our proposed step-by-step approach in the treatment of IAH. RESULTS: Results: Systemic complications occurred in 12 patients of the main group (11,8%) and in 46 patients of the comparison group (54,1%), while in the second group the frequency of systemic complications was significantly higher (χ2 = 38,6, CI 29,3-53,6, p <0,0001). 20 patients (10,7%) died (2 patients of the main group (1,96%) and 18 patients of the comparison group (21,2%) (χ2 = 17,85, CI 10,4-29,18, p <0,0001). CONCLUSION: Conclusions: Use in the complex treatment of patients with acute surgical pathology of the abdominal cavity, accompanied by IAH, the proposed step-by-step approach has improved treatment outcomes by reducing the incidence of systemic complications from 54,1% to 11,8%, total mortality from 21,2% to 1,96% and postoperative mortality - from 22,4% to 2,4%.

[Etiology and pathogenesis of infected pancreatic necrosis]. / Etiologiya i patogenez infitsirovannogo pankreonekroza.

Modern literature data confirm the central role of intestinal barrier complex not only as a target in acute necrotizing pancreatitis, but also as a trigger for septic complications. Intra-abdominal hypertension, endothelial dysfunction and gut microbiome changes following necrotizing pancreatitis might have an independent impact on acute intestinal distress syndrome and bacterial translocation. Monitoring of these conditions and early target therapy can improve the outcomes in patients with severe acute pancreatitis. Adverse outcomes of infected pancreatic necrosis including high mortality and morbidity are largely due to the prevalence of multidrug-resistant bacterial pathogens.

Surveillance to detect colonic ischemia with extraluminal pH measurement after open surgery for abdominal aortic aneurysm.

OBJECTIVE: Colonic ischemia (CI) is a life-threatening complication after aortic surgery. Postoperative surveillance of colonic perfusion might be warranted. The aim of the present study was to evaluate the safety and feasibility of postoperative extraluminal pH measurement (pHe) using colonic tonometry after open abdominal aortic aneurysm (AAA) repair. METHODS: Before closing the abdomen after open AAA repair, a tonometric catheter was placed transabdominally in contact with the sigmoid colon serosa, similar to a drainage catheter. Extraluminal partial pressure of carbon dioxide was measured postoperatively and combined with arterial blood gas analysis to calculate the pHe. The measurements were repeated every 4 hours with simultaneous intra-abdominal pressure measurements. The threshold for colonic malperfusion was set at pHe <7.2. RESULTS: A total of 27 patients were monitored, 12 had undergone surgery for ruptured AAAs and 15 for intact AAAs. Of the 27 patients, 4 developed clinically significant CI requiring surgery. All four cases were preceded by a prolonged (>5 hours) pHe <7.2 indicating malperfusion. A fifth patient, who, during monitoring, had had the lowest pHe of 7.21, developed mild CI with the onset after completion of monitoring, which was successfully managed conservatively. Seven patients who had had brief durations (<5 hours) of pHe <7.2 did not develop clinical signs of CI or any related adverse events. CONCLUSIONS: Measurements of pHe using colonic tonometry indicated malperfusion in all four patients who had developed clinically significant CI. A shorter duration of low pHe was well tolerated without any signs of CI. Measurement of pHe was safe and reliable for the surveillance of colonic perfusion after open aortic surgery, indicating a promising technique. However, larger studies are needed.

Reliability of Pulse Contour Cardiac Output Analysis in a Piglet Model of Multi-step Intra-abdominal Hypertension.

BACKGROUND: Pulse contour cardiac output (PCCO) analysis is a minimally invasive technique for continuous cardiac output (CO) measurement monitoring. PCCO requires calibration by transpulmonary thermodilution (TPTD). Studies showed good agreement between PCCO, TPTD CO and CO measured by pulmonary artery thermodilution (PATD) during stable hemodynamics. However, data are limited in patients with intra-abdominal hypertension (IAH). The objective is to compare the agreement between PCCO, TPTD CO, and PATD CO in a piglet model of multi-step IAH. MATERIALS AND METHODS: Ten female domestic piglets were enrolled in this study. IAH was induced by stepwise carbon dioxide inflation into peritoneal cavity in anesthetized piglets. Following baseline registrations, intra-abdominal pressure (IAP) was increased and maintained at each IAP plateau of 10, 20, 30, and 40 mmHg for 15 min before CO measurements. CO was measured by PATD and simultaneously by 2 femoral artery PCCO catheters. One PCCO catheter was recalibrated by TPTD at each IAP plateau while the other was only calibrated at baseline. RESULTS: In pooled data of different IAP stages, TPTD CO and recalibrated PCCO (R-PCCO) showed excellent correlation (r2 = 0.94 and 0.93) and small bias (-0.09 and -0.09 L/min), respectively, compared with PATD CO. However, PCCO without recalibration (NR-PCCO) were not accurate during IAH (r2 = 0.58, bias: +0.32 L/min). When IAP increased to 30 mmHg, NR-PCCO failed to agree with PATD CO (r2 = 0.47, bias: +0.52 L/min). On the contrary, a clinically accepted agreement between TPTD CO, R-PCCO, and PATD CO was observed at different IAP stages. CONCLUSIONS: TPTD CO and R-PCCO agreed with PATD CO in this piglet model of multi-step IAH. On the contrary, NR-PCCO failed to agree with PATD CO when IAP increased to 30 mmHg or more. PCCO analysis needs recalibration in this condition.

Incidence of Intra-Abdominal Hypertension and Abdominal Compartment Syndrome: A Systematic Review.

OBJECTIVE: To determine the contemporary prevalence of intra-abdominal hypertension (IAH) and abdominal compartment syndrome in critically ill patients. DATA SOURCES: Medline, Embase, and Central databases. STUDY SELECTION: Studies reporting on the prevalence of IAH in consecutively admitted critically ill patients using the World Society of Abdominal Compartment Syndrome (WSACS) consensus guidelines for intra-abdominal pressure (IAP) measurement. DATA EXTRACTION: Duplicate independent review and data abstraction. DATA SYNTHESIS: The search identified 2428 titles with 6 eligible studies (n = 1965). Reported prevalence ranged from 30% to 49%. Despite abiding by the WSACS guidelines for IAP measurement, studies varied in their definition of IAH, frequency and duration of IAP measurement, and reporting of outcomes. Three of 6 studies reported that IAH, especially at higher grades, was an independent predictor of mortality. CONCLUSIONS: Intra-abdominal hypertension is a common finding in critically ill patients and may be associated with increased mortality, especially at higher grades. Further prospective research is required to examine the effect of screening and treatment of IAH on patient outcomes.

Physiology of intra-abdominal volume during pregnancy.

A total of 580 pregnant and 50 puerperal women were included in this cross-sectional study to assess the physiological changes that allow women to adapt to a chronic increase in intra-abdominal pressure during pregnancy. The volume of the uterus, intra-abdominal volume (IAV), visceral and subcutaneous fat was calculated. During pregnancy, the IAV increases up to 1.5 times. Changes in IAV until 24 weeks present a linear relationship (5.2%); thereafter, changes become exponential and, at 40 weeks, IAV increases by 61%. This fact is exclusively related to the progressive growth of the foetus and to the increase in uterine size. At term, the IAV reserve is exhausted, becoming equal the anteroposterior and transverse diameters of the abdomen.In conclusion, the adaptive capabilities of IAV related to the foetal growth are limited by the IAV reserve. The reserve capacity of the IAV and tensile properties of the abdominal wall can be estimated by the dynamics of the anteroposterior and transverse abdominal diameters.IMPACT STATEMENTWhat is already known on this subject? A causal relationship between intra-abdominal hypertension and the development of adverse obstetric and perinatal outcomes has been suggested. Nevertheless, the role of this condition as a leading cause of systemic dysfunction during pregnancy remains unrecognised and underestimated.What do the results of this study add? This study assesses the dynamics of IAV in uncomplicated singleton pregnancies.What are the implications of these findings for clinical practice and/or further research? The study of abdominal pressure indicators such as intra-abdominal volume and compliance will help to a better understand the aetiology, pathophysiology, prognosis and treatment strategies for pregnant women with intra-abdominal hypertension.

Reduction of intra-abdominal pressure after percutaneous catheter drainage of pancreatic fluid collection predicts survival.

OBJECTIVE: Intra-abdominal hypertension (IAH) can adversely affect the outcome in patients of acute pancreatitis (AP). Effect of percutaneous drainage (PCD) on IAH has not been studied. We studied the effect of PCD on IAH in patients with acute fluid collections. MATERIAL AND METHODS: Consecutive patients of AP undergoing PCD between Jan 2016 and May 2018 were evaluated for severity markers, clinical course, hospital and ICU stay, and mortality. Patients were divided into two groups: with IAH and with no IAH (NIAH). The two groups were compared for severity scores, organ failure, hospital and ICU stay, reduction in IAP and mortality. RESULTS: Of the 105 patients, IAH was present in 48 (45.7%) patients. Patients with IAH had more often severe disease, BISAP ≥2, higher APACHE II scores and computed tomography severity index (CTSI). IAH group had more often OF (87.5% vs. 70.2%, p = 0.033), prolonged ICU stay (12.5 vs. 6.75 days, p = 0.007) and higher mortality (52.1% vs. 15.8%, p < 0.001). After PCD, IAP decreased significantly more in the IAH group (21.85 ± 4.53 mmHg to 12.5 ± 4.42 mmHg) than in the NIAH group (12.68 ± 2.72 mmHg to 8.32 ± 3.18 mmHg), p = <0.001. Reduction of IAP in patients with IAH by >40% at 48 h after PCD was associated with better survival (63.3% vs. 36.7%, p = 0.006). CONCLUSION: We observed that patients with IAH have poor outcome. PCD decreases IAP and a fall in IAP >40% of baseline value predicts a better outcome after PCD in patients with acute fluid collections.