Acute Mesenteric Ischemia

Acute mesenteric ischemia (AMI) is a vascular emergency caused by sudden reduction or cessation of blood flow to the small intestine and/or colon, resulting in intestinal ischemia, infarction, and potentially fatal bowel necrosis with peritonitis and sepsis. AMI carries a mortality rate of 60-80% largely because of delayed diagnosis -- the classic clinical presentation of severe abdominal pain out of proportion to physical findings is frequently misdiagnosed or attributed to other causes, allowing ischemia to progress to irreversible transmural infarction. The registered nurse's role in early recognition through systematic assessment and high clinical suspicion is critical for improving outcomes in this time-sensitive condition. The mesenteric circulation supplies blood to the entire gastrointestinal tract through three major vessels. The celiac artery (celiac trunk) supplies the foregut structures: esophagus, stomach, duodenum (proximal), liver, spleen, and pancreas. The superior mesenteric artery (SMA) is the largest and most clinically significant, supplying the midgut structures: duodenum (distal), jejunum, ileum, cecum, ascending colon, and transverse colon (proximal two-thirds). The inferior mesenteric artery (IMA) supplies the hindgut: transverse colon (distal one-third), descending colon, sigmoid colon, and rectum....