Background: Acute mesenteric ischemia (AMI) is a rare but severe complication after cardiac surgery. However, AMI is likely to be more frequent in the subgroup of patients presenting with multiple organ failure after a cardiac surgery. The primary objective of this study was to identify AMI risk factors among patients requiring intensive care unit (ICU) admission after cardiac surgery.
Methods: Retrospective observational study of all the patients requiring admission to two ICUs in a large university hospital after a cardiac surgery procedure. AMI confirmation was based on abdominal computed tomography scan, digestive endoscopy, laparotomy, or postmortem examination. Univariate and multivariate analyses were done to compare pre- and in-ICU characteristics between patients with or without AMI.
Results: Between 2007 and 2013, a cardiac surgery was performed in 4,948 patients, of whom 320 patients (6%) required ICU admission for multiple organ failure. AMI was confirmed in 10% of the patients admitted to the ICU for multiple organ failure (33/320). The prognosis of these patients was extremely poor with 28- and 90-day mortality rates of 64% and 83%, respectively. Nonocclusive mesenteric ischemia (NOMI) was the main mechanism involved in 83% of the patients. Coronary artery bypass graft, need for blood transfusion during cardiopulmonary bypass, aspartate aminotransferase at least 100 UI/L, and Simplified Acute Physiology Score II at least 50 at ICU admission were independently associated with AMI. An AMI risk score based upon these four risk factors was able to identify three classes of risk: low risk (<1%), intermediate risk (9%), and high risk (29%).
Conclusion: AMI is a frequent condition among patients presenting with multiple organ failure after cardiac surgery, occurring in 10% of them. The prognosis of AMI is extremely poor. The main mechanism of AMI is NOMI, occurring in approximately 80% of patients. Further progress should be performed on prevention and earlier diagnosis.