Predictors of Transmural Non-Occlusive Mesenteric Ischemia in ICU Patients With Suspected Acute Mesenteric Ischemia

Mesenteric Ischemia in the ICU: A Prospective Observational Study Across Estonian Regional Hospitals

Acute mesenteric ischemia (AMI) is a rare but life-threatening condition associated with high mortality and major diagnostic challenges due to nonspecific clinical presentation and limited reliable biomarkers. Critically ill patients in the intensive care unit (ICU) are at particularly high risk of non-occlusive mesenteric ischemia (NOMI), a subtype of AMI characterized by impaired mesenteric perfusion without large-vessel occlusion. Despite advances in imaging, the diagnosis of NOMI remains difficult, and data specifically focusing on ICU patients with suspected AMI are limited.

This prospective observational multicenter study aims to identify independent predictors of transmural NOMI among ICU patients with suspected AMI. In addition, the study will describe demographics, comorbidities, clinical presentation, laboratory findings, diagnostic imaging, management strategies, and outcomes among ICU patients with NOMI, other forms of AMI, and patients with suspected but unconfirmed AMI. Consecutive adult ICU patients in whom clinical suspicion of AMI arises during ICU stay will be included across Estonian regional hospitals. The study is a local continuation of the international AMESI study, with a specific focus on critically ill ICU patients.

Inclusion criteria

- Adult ICU patients in whom clinical suspicion of acute mesenteric ischemia is raised during their ICU stay.

Exclusion criteria

• Patients who develop acute mesenteric ischemia outside of the intensive care unit,
• Confirmed strangulating bowel obstruction,
• Individuals younger than 18 years,
• Chronic mesenteric ischemia without an acute event.