Mild to moderate intra-abdominal hypertension: Does it matter?

Source control in intra-abdominal infections: What you need to know

ABSTRACT

Providing optimal source control (SC) for intra-abdominal sepsis (IAS) is a critically important surgical principle, yet one that remains nebulous in terms of strict definitions and required conduct. The entire concept of SC has evolved in the last decades. Contemporary SC is not only surgical but also embraces minimally invasive percutaneous and medical therapies. We propose that adequate SC has evolved from the mere anatomical control of enteric leakage, cleansing of obvious contaminants and necrosis, to a more comprehensive anatomo-phyiological-biochemical model. While any breaches in the integrity of the gastrointestinal tract should be addressed urgently, SC should ultimately aim to control the generation and propagation of systemic biomediators, bacterial toxins, and toxic catabolites that perpetuate multisystem organ failure and death. Much urgently needs to be learned to understand and hopefully mitigate the dysbiotic influences of IAS on the human microbiome. Finally, the therapy offered should always be individualized, recognizing patient's unique pathophysiology, clinical condition, comorbidities, and predeclared preferences regarding invasive therapies and life-support.

International cross-sectional survey on current and updated definitions of intra-abdominal hypertension and abdominal compartment syndrome

BACKGROUND

The Abdominal Compartment Society (WSACS) established consensus definitions and recommendations for the management of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) in 2006, and they were last updated in 2013. The WSACS conducted an international survey between 2022 and 2023 to seek the agreement of healthcare practitioners (HCPs) worldwide on current and new candidate statements that may be used for future guidelines.

METHODS

A self-administered, online cross-sectional survey was conducted under the auspices of the WSACS to assess the level of agreement among HCPs over current and new candidate statements. The survey, distributed electronically worldwide, collected agreement or disagreement with statements on the measurement of intra-abdominal pressure (IAP), pathophysiology, definitions, and management of IAH/ACS. Statistical analysis assessed agreement levels, expressed in percentages, on statements among respondents, and comparisons between groups were performed according to the respondent's education status, base specialty, duration of work experience, role (intensivist vs non-intensivist) and involvement in previous guidelines. Agreement was considered to be reached when 80% or more of the respondents agreed with a particular statement.

RESULTS

A total of 1042 respondents from 102 countries, predominantly physicians (73%), of whom 48% were intensivists, participated. Only 59% of HCPs were aware of the 2013 WSACS guidelines, and 41% incorporated them into practice. Despite agreement in most statements, significant variability existed. Notably, agreement was not reached on four new candidate statements: "normal intra-abdominal pressure (IAP) is 10 mmHg in critically ill adults" (77%), "clinical assessment and estimation of IAP is inaccurate" (65.2%), "intragastric can be an alternative to the intravesical route for IAP measurement" (70.4%), and "measurement of IAP should be repeated in the resting position after measurement in a supine position" (71.9%). The survey elucidated nuances in clinical practice and highlighted areas for further education and standardization.

CONCLUSION

More than ten years after the last published guidelines, this worldwide cross-sectional survey collected feedback and evaluated the level of agreement with current recommendations and new candidate statements. This will inform the consensus process for future guideline development.

Source Control and Antibiotics in Intra-Abdominal Infections

Intra-abdominal infections (IAIs) account for a major cause of morbidity and mortality, representing the second most common sepsis-related death with a hospital mortality of 23-38%. Prompt identification of sepsis source, appropriate resuscitation, and early treatment with the shortest delay possible are the cornerstones of management of IAIs and are associated with a more favorable clinical outcome. The aim of source control is to reduce microbial load by removing the infection source and it is achievable by using a wide range of procedures, such as definitive surgical removal of anatomic infectious foci, percutaneous drainage and toilette of infected collections, decompression, and debridement of infected and necrotic tissue or device removal, providing for the restoration of anatomy and function. Damage control surgery may be an option in selected septic patients. Intra-abdominal infections can be classified as uncomplicated or complicated causing localized or diffuse peritonitis. Early clinical evaluation is mandatory in order to optimize diagnostic testing and establish a therapeutic plan. Prognostic scores could serve as helpful tools in medical settings for evaluating both the seriousness and future outlook of a condition. The patient's conditions and the potential progression of the disease determine when to initiate source control. Patients can be classified into three groups based on disease severity, the origin of infection, and the patient's overall physical health, as well as any existing comorbidities. In recent decades, antibiotic resistance has become a global health threat caused by inappropriate antibiotic regimens, inadequate control measures, and infection prevention. The sepsis prevention and infection control protocols combined with optimizing antibiotic administration are crucial to improve outcome and should be encouraged in surgical departments. Antibiotic and antifungal regimens in patients with IAIs should be based on the resistance epidemiology, clinical conditions, and risk for multidrug resistance (MDR) and Candida spp. infections. Several challenges still exist regarding the effectiveness, timing, and patient stratification, as well as the procedures for source control. Antibiotic choice, optimal dosing, and duration of therapy are essential to achieve the best treatment. Promoting standard of care in the management of IAIs improves clinical outcomes worldwide. Further trials and stronger evidence are required to achieve optimal management with the least morbidity in the clinical care of critically ill patients with intra-abdominal sepsis.

Intra-abdominal hypertension and compartment syndrome after complex hernia repair

PURPOSE

Abdominal compartment syndrome (ACS) is a well-known concept after trauma surgery or after major abdominal surgery in critically ill patients. However, ACS as a complication after complex hernia repair is considered rare and supporting literature is scarce. As complexity in abdominal wall repair increases, with the introduction of new tools and advanced techniques, ACS incidence might rise and should be carefully considered when dealing with complex abdominal wall hernias. In this narrative review, a summary of the current literature will highlight several key features in the diagnosis and management of ACS in complex abdominal wall repair and discuss several treatment options during the different steps of complex AWR.

METHODS

We performed a literature search across PubMed using the search terms: "Abdominal Compartment syndrome," "Intra-abdominal pressure," "Complex abdominal hernia," and "Ventral hernia." Articles corresponding to these search terms were individually reviewed by primary author and selected on relevance.

CONCLUSION

Intra-abdominal hypertension (IAH) and ACS require imperative attention and should be carefully considered when dealing with complex abdominal wall hernias, even without significant loss of domain. Development of a true abdominal compartment syndrome is relatively rare, but is a devastating complication and should be prevented at all cost. Current evidence on surgical treatment of ACS after hernia repair is scarce, but conservative management might be an option in the early phase and low grades of IAH. However, life-saving treatment by relaparotomy and open abdomen management should be initiated when ACS starts setting in.

Source control in emergency general surgery: WSES, GAIS, SIS-E, SIS-A guidelines

Intra-abdominal infections (IAI) are among the most common global healthcare challenges and they are usually precipitated by disruption to the gastrointestinal (GI) tract. Their successful management typically requires intensive resource utilization, and despite the best therapies, morbidity and mortality remain high. One of the main issues required to appropriately treat IAI that differs from the other etiologies of sepsis is the frequent requirement to provide physical source control. Fortunately, dramatic advances have been made in this aspect of treatment. Historically, source control was left to surgeons only. With new technologies non-surgical less invasive interventional procedures have been introduced. Alternatively, in addition to formal surgery open abdomen techniques have long been proposed as aiding source control in severe intra-abdominal sepsis. It is ironic that while a lack or even delay regarding source control clearly associates with death, it is a concept that remains poorly described. For example, no conclusive definition of source control technique or even adequacy has been universally accepted. Practically, source control involves a complex definition encompassing several factors including the causative event, source of infection bacteria, local bacterial flora, patient condition, and his/her eventual comorbidities. With greater understanding of the systemic pathobiology of sepsis and the profound implications of the human microbiome, adequate source control is no longer only a surgical issue but one that requires a multidisciplinary, multimodality approach. Thus, while any breach in the GI tract must be controlled, source control should also attempt to control the generation and propagation of the systemic biomediators and dysbiotic influences on the microbiome that perpetuate multi-system organ failure and death. Given these increased complexities, the present paper represents the current opinions and recommendations for future research of the World Society of Emergency Surgery, of the Global Alliance for Infections in Surgery of Surgical Infection Society Europe and Surgical Infection Society America regarding the concepts and operational adequacy of source control in intra-abdominal infections.

Goal-Directed Fluid Therapy Enhances Gastrointestinal Recovery after Laparoscopic Surgery: A Systematic Review and Meta-Analysis

(1) Background: Whether goal-directed fluid therapy (GDFT) provides any outcome benefit as compared to non-goal-directed fluid therapy (N-GDFT) in elective abdominal laparoscopic surgery has not been determined yet. (2) Methods: A systematic literature search was conducted in MEDLINE, Embase, CENTRAL, Web of Science, and Scopus. The main outcomes were length of hospital stay (LOHS), time to first flatus and stool, intraoperative fluid and vasopressor requirements, serum lactate levels, and urinary output. Pooled risks ratios (RRs) with 95% confidence intervals (CI) were calculated for dichotomous outcomes and weighted mean difference (WMD) with 95% CI for continuous outcomes. (3) Results: Eleven studies were included in the quantitative, and fifteen in the qualitative synthesis. LOHS (WMD: -1.18 days, 95% CI: -1.84 to -0.53) and time to first stool (WMD: -9.8 h; CI -12.7 to -7.0) were significantly shorter in the GDFT group. GDFT resulted in significantly less intraoperative fluid administration (WMD: -441 mL, 95% CI: -790 to -92) and lower lactate levels at the end of the operation: WMD: -0.25 mmol L-1; 95% CI: -0.36 to -0.14. (4) Conclusions: GDFT resulted in enhanced recovery of the gastrointestinal function and shorter LOHS as compared to N-GDFT.

COVID-19 and Indirect Liver Injury: A Narrative Synthesis of the Evidence

The liver is frequently affected by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection. The most common manifestations are mildly elevated alanine aminotransferase and aspartate aminotransferase, with a prevalence of 16-53% among patients. Cases with severe coronavirus disease 2019 (COVID-19) seem to have higher rates of acute liver dysfunction, and the presence of abnormal liver tests at admission signifies a higher risk of severe disease during hospitalization. Patients with chronic liver diseases also have a higher risk of severe disease and mortality (mainly seen in patients with metabolic-associated fatty liver disease). Several pathways of damage have been proposed in the liver involvement of COVID-19 patients; although, the end-cause is most likely multifactorial. Abnormal liver tests have been attributed to the expression of angiotensin-converting enzyme 2 receptors in SARS-CoV-2 infection. This enzyme is expressed widely in cholangiocytes and less in hepatocytes. Other factors attributed to liver damage include drug-induced liver injury, uncontrolled release of proinflammatory molecules ("cytokine storm"), pneumonia-associated hypoxia, and direct damage by the infection. Hepatic steatosis, vascular thrombosis, fibrosis, and inflammatory features (including Kupffer cell hyperplasia) are the most common liver histopathological findings in deceased COVID-19 patients, suggesting important indirect mechanisms of liver damage. In this translational medicine-based narrative review, we summarize the current data on the possible indirect mechanisms involved in liver damage due to COVID-19, the histopathological findings, and the impact of these mechanisms in patients with chronic liver disease.

Comparison of Intra-Abdominal Pressure Measurements in Critically Ill Patients Using Intravesical Normal Saline at 15°C, 25°C, and 35°C

Background

The incidence of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) in intensive care units is high. Dynamic monitoring of intra-abdominal pressure (IAP) is important to treat patients with these conditions. The World Society of Abdominal Compartment Syndrome revised IAP measurement and treatment guidelines in 2013. IAP is measured by instilling ≤25 mL of sterile saline into the bladder, but there is no requirement for the saline to be at a specific temperature. Many doctors presume that using cold saline will trigger bladder muscle spasms, resulting in measurement error. In the present study, we investigated the effect of body-temperature saline on IAP measurements.

Material/Methods

A single-center study was conducted in 12 patients with IAH over a 2-year period. IAP was measured via the bladder with instillation of sterile saline at temperatures of 35°C, 25°C, and 15°C. We analyzed the data using R software, version 4.1.0. Paired t tests were used for comparisons between groups. A Spearman rank correlation analysis was performed to compare groups. Analysis results were plotted using the R packages ggplot2, ggpubr, and BlandAltmanLeh. P<0.05 was considered statistically significant.

Results

There was a significant difference in IAP measurement between the 15°C and 35°C groups (t=−2.55, P=0.027). There was no significant difference between the 25°C and 35°C groups (t=0.73, P=0.48). Bland-Altman analysis showed that IAP was consistent in the 25°C and 35°C groups.

Conclusions

Although it is preferable to measure IAP with saline at body temperature (35°C), a temperature >25°C is associated with accurate results. Using saline at <15°C should be avoided.

The Correlation of Intraabdominal Pressure With Renal Resistive Index

BACKGROUND

To evaluate the correlation between intraabdominal pressure (IAP) measured via the bladder and renal resistive index (RRI) measured by Doppler ultrasonography (USG).

METHODS

Eighty consecutive surgical patients were included into this study. Before Doppler USG evaluation, IAP was measured by a Foley catheter via the bladder. The left and right RRI, the diameters of the inferior vena cava and portal vein were measured by colored Doppler USG. Spearman correlation analysis was used to evaluate the correlation between different measurements. Intraabdominal hypertension (IAH) was defined as of IAP ≥ 12 mmHg. Significantly different variables from the univariate analysis between patients with and without IAH were entered into backward stepwise binary logistic regression analysis of IAH as the dependent variable. P values < 0.05 were accepted as statistically significant.

RESULTS

In total, 80 patients were included into study. In 27 patients (34%) IAP was normal and in 53 patients (66%) IAH was diagnosed. The Spearman correlation analysis of IAP and the ultrasonographic measurements revealed a strong correlation between RRI and IAP (P < 0.001). Patients with IAH were more likely to be diabetic and had abdominal incisional hernia compared with patients with normal IAP (P < 0.05). The results of the multivariate logistic regression analysis revealed right RRI as the only independent predictor of IAH (B: 57.04, S. E.: 13.7, P < 0.001).

CONCLUSIONS

There is a strong correlation between IAP and RRI. RRI can be an alternative, noninvasive technique for the diagnosis and follow-up of IAH after further evaluations in different patient groups.

Abdominal compartment syndrome and intra-abdominal hypertension in critically ill patients: diagnostic value of computed tomography

AIMS

The aims of the present work were to reevaluate, prospectively, the diagnostic value of already-described computed tomography (CT) landmarks of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) and to study the diagnostic value of some undescribed CT signs for the diagnosis of IAH and ACS.

MATERIALS AND METHODS

Consecutive patients admitted to the intensive care unit (ICU) in shock for whom an abdominal CT was clinically indicated were included. CT examinations were reviewed and scored by two reviewers for the 12 proposed CT features of IAH and ACS. Intravesical pressure (IVP) was measured for each patient. Imaging features and clinical data of patients with IAH (IVP ≥ 12 mmHg) were compared to those of patients with normal intra-abdominal pressure (IVP < 12 mmHg).

RESULTS

Forty-one patients were included. Twenty-one patients (51%) presented IAH with an IVP value ≥ 12 mmHg. Four patients (10%) were considered to have ACS (10%). Only an increased peritoneal-to-abdominal height ratio (PAR) was associated with the presence of IAH (PAR = 0.45 [0.40-0.49] in patients with IVP < 12 mmHg and PAR = 0.52 [0.48-0.53] in patients with IVP ≥ 12 mmHg; p < 0.001). Increased PAR ≥ 0.52 had a specificity of 85% for IAH diagnosis.

CONCLUSION

The present study suggests that a PAR ≥ 0.52 could help radiologists to identify IAH on abdominal CT scan and could lead to adequate identification and/or treatment, even at early stages of IAH.

KEY POINTS

• CT is an efficient first-intention procedure to evaluate and follow up underlying conditions in critically ill patients at risk of IAH and ACS overcome. • Raising the possibility of an IAH on a CT examination is relevant information for the clinician. • The only factors associated with intra-abdominal hypertension were the peritoneal-to-abdominal height ratio (PAR) and the ratio of maximal anteroposterior to transverse abdominal diameter (which define the round belly sign when > 0.8).

The Duration of Intra-abdominal Hypertension and Increased Serum Lactate Level are Important Prognostic Markers in Critically Ill Surgical Patient's Outcome: A Prospective, Observational Study

Aim:

The present study analyzed the clinical significance of duration of intra-abdominal hypertension (IAH) associated with increased serum lactate in critically ill patients with severe sepsis.

Materials and Methods:

Our study was an observational, prospective study carried out in the Surgical Intensive Care Unit (ICU) at J.L.N Medical College, Ajmer, Rajasthan, India. In our study, we included a total of 100 patients and intra-abdominal pressure (IAP) was measured through intravesical route at the time of admission and after 6, 12, 24, 48, and 72 h via a urinary catheter filled with 25 ml of saline. Duration of ICU and hospital stay, need for ventilator support, initiation of enteral feeding, serum lactate level at time of admission and after 48 h, and 30-day mortality were noted as outcomes.

Results:

In our study, an overall incidence of IAH was 60%. Patients with cardiovascular surgery and renal and pulmonary dysfunction were 93.3%, 55%, and 60%, respectively, at the time of admission and 65%, 10%, and 10%, respectively, after 72 h of admission in the surgical ICU. Nonsurvivors had statistically significant higher IAP and serum lactate levels than survivors. Patients with longer duration of IAH had longer ICU and hospital stay, longer duration of vasopressors and ventilator support, and delayed enteral feeding.

Conclusion:

There is a strong relationship “risk accumulation” between duration of IAH associated with increased serum lactate and organ dysfunction. The duration of IAH was an independent predictor of 30-day mortality. Early recognition and prompt intervention for IAH and severe sepsis are essential to improve the patient outcomes.

Successful non-operative management of intraabdominal hypertension and abdominal compartment syndrome after complex ventral hernia repair: a case series

BACKGROUND

Intraabdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are devastating complications of surgery. Patients who undergo complex ventral hernia repair (CVHR) may be at risk for IAH and ACS.

METHODS

We performed a retrospective review of 175 patients who underwent CVHR by a single surgeon. Body mass index (BMI), prior hernia repair, operative time, bladder pressure, serum creatinine, sedation, paralytic therapy, and ventilator support were reviewed.

RESULTS

IAH was identified in 33 patients; 11 patients developed ACS. Paralytic therapy was employed in 29 patients for an average of 1.4 days. Elevated BMI was independently associated with an increased risk of IAH (p = 0.006) and ACS (p = 0.02).

CONCLUSION

Patients who undergo CVHR are at risk of developing IAH and ACS in the postoperative period. Elevated BMI and longer operative time are independent risk factors for the development of IAH. IAH and ACS can be successfully managed with surgical critical care.

Reduction of Intra-abdominal Hypertension Is Associated with Increase of Cardiac Output in Critically Ill Patients Undergoing Mechanical Ventilation

Objective: To demonstrate the relationship between intra-abdominal hypertension (IAH) and cardiac output (CO) in mechanically ventilated (MV), critically ill patients.

Material and methods: This was a single-center, prospective study performed between January and April 2016, on 30 mechanically ventilated patients (mean age 67.3 ± 11.9 years), admitted in the Intensive Care Unit (ICU) of the Emergency County Hospital of Tîrgu Mureș, Romania, who underwent measurements of intra-abdominal pressure (IAP). Patients were divided into two groups: group 1 – IAP <12 mmHg (n = 21) and group 2 – IAP >12 mmHg (n = 9). In 23 patients who survived at least 3 days post inclusion, the variation of CO and IAP between baseline and day 3 was calculated, in order to assess the variation of IAP in relation to the hemodynamic status.

Results: IAP was 8.52 ± 1.59 mmHg in group 1 and 19.88 ± 8.05 mmHg in group 2 (p <0.0001). CO was significantly higher in group 1 than in the group with IAH: 6.96 ± 2.07 mmHg (95% CI 6.01–7.9) vs. 4.57 ± 1.23 mmHg (95% CI 3.62–5.52) (p = 0.003). Linear regression demonstrated an inverse correlation between CO and IAP (r = 0.48, p = 0.007). Serial measurements of CO and IAP proved that whenever accomplished, the decrease of IAP was associated with a significant increase in CO (p = 0.02).

Conclusions: CO is significantly correlated with IAP in mechanically ventilated patients, and IAH reduction is associated with increase of CO in these critically ill cases.

MICU1 may be a promising intervention target for gut-derived sepsis induced by intra-abdominal hypertension

Intra-abdominal hypertension (IAH) is a common and serious complication in critically ill patients, for which there is no targeted therapy. IAH-induced dysfunction of intestinal barriers is closely associated with oxidative imbalances, which are considered to provide a pathophysiological basis for subsequent gut-derived sepsis. However, the upstream mechanism that produces oxidative damage during IAH remains unknown. It is not clear whether ‘mitochondrial Ca²⁺ uptake 1’ (MICU1, the key protein regulating the oxidative process) is involved in preventing Ca²⁺_m (mitochondrial Ca²⁺) overload. Here, we detected changes in the expression of MICU1 during the development of increased intestinal permeability in rats with IAH, and we explored the related mechanism regulating epithelial-barrier functions by knocking-down micu1 in Caco-2 cells. Our results demonstrated that, to combat IAH-induced dysfunction of intestinal barriers, MICU1 undergoes a compensatory increase in expression, whereas ‘mitochondrial calcium uniporter’ (MCU) – a conserved Ca²⁺ transporter – becomes transcriptionally suppressed. Silencing the expression of MICU1 destroyed Caco-2 cell barrier integrity, promoted paracellular permeability, and impaired the expression of tight junction proteins (occludin, ZO-1, and claudin 1). Meanwhile, oxidative imbalances were induced; malondialdehyde (MDA), a product of oxidation, was increased and antioxidant products (GSH-Px, CAT, and SOD) were decreased. In MICU1-deficient Caco-2 cells, proliferation was inhibited and apoptosis was promoted. Collectively, our results indicate that MICU1-related oxidation/antioxidation disequilibrium is strongly involved in IAH-induced damage to intestinal barriers. MICU1-targeted treatment may hold promise for preventing the progression of IAH to gut-derived sepsis.