Intra-abdominal hypertension as a trigger of "gut failure" in SARS-CoV-2 infection: Effect of open abdomen (OA) and negative pressure therapy (NPT) on respiratory and gastrointestinal (GI) function

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.

Acute mesenteric ischemia and small bowel imaging findings in COVID-19: A comprehensive review of the literature

BACKGROUND

Coronavirus disease 2019 (COVID-19), an infectious condition caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly spread worldwide since its first description in Wuhan in December 2019. Even though respiratory manifestations are the most prevalent and responsible for disease morbidity and mortality, extrapulmonary involvement has progressively gained relevance. In particular, gastrointestinal (GI) signs and symptoms, reported in up to two-thirds of patients with COVID-19, might represent the first and, in some cases, the only disease presentation. Their presence has been associated in some studies with an increased risk of a severe disease course. Proposed pathogenic mechanisms explaining GI tract involvement are either direct viral access to intestinal cells via angiotensin-converting enzyme 2 or indirect damage of the intestinal wall through mesenteric ischemia induced by the hypercoagulable state associated with COVID-19 infection. Although not typical of SARS-CoV-2 infection, several small bowel manifestations have been described in infected patients who underwent any form of abdominal imaging. The radiological findings were mainly reported in patients with abdominal symptoms, among which abdominal pain was the most common.

AIM

To discuss small bowel radiological manifestations of SARS-CoV-2 infection in abdominal imaging studies.

METHODS

Bibliographical searches were performed in PubMed, using the following keywords: “COVID-19” AND “imaging” AND “gastrointestinal” OR “abdominal” OR “small bowel”.

RESULTS

Of 62 patients with described radiologic small bowel alterations, mesenteric ischemia was diagnosed in 31 cases (50%), small bowel wall thickening in 10 cases (16%), pneumatosis in nine cases (15%), intussusception in eight cases (13%), pneumoperitoneum in two cases (3%) and paralytic ileus in two cases (3%). We also reported mesenteric adipose tissue hypertrophy and lymph nodes enlargement in a young woman.

CONCLUSION

So far it is difficult to establish whether these manifestations are the direct consequence of SARS-CoV-2 infection or collateral findings in infected patients, but their recognition would be pivotal to set a closer follow-up and to reduce missed diagnoses.

Abdominal imaging findings in patients with SARS-CoV-2 infection: a scoping review

PURPOSE

This scoping review evaluated the currently available data related to abdominal imaging in the SARS-CoV-2 infection.

METHOD

A systematic review of MEDLINE, EMBASE, SCOPUS, and Web of Science was performed from inception to July 15, 2020 using PRISMA-ScR guidelines. The review included case reports and series discussing radiologic manifestations of SARS-CoV-2 infection in abdominal imaging studies. Studies published from inception to March 31, 2020, were independently screened and reviewed by one author, and another author reviewed studies published after March 31 to July 15, 2020. Study screening and full-text review for publications before March 31, 2020, was performed by one author, and another author for publications after March 31 to July 15, 2020.

RESULTS

Thirty-six studies were included in qualitative synthesis. The prevalence of gastrointestinal symptoms is roughly 18% and includes loss of appetite, nausea, vomiting, diarrhea, and abdominal pain. Sixteen percent of COVID-19 cases may only present with gastrointestinal symptoms. Many patients presenting this way demonstrate evidence of COVID-19 incidentally through abdominal CT imaging at the lung bases. Studies published to date have also reported abdominal imaging findings including small and large bowel wall thickening, fluid-filled colon, pneumatosis intestinalis, pneumoperitoneum, intussusception, and ascites.

CONCLUSION

Gastrointestinal manifestations and imaging manifestations of SARS-CoV-2 infection are increasingly reported and warrant specific attention during abdominal imaging.