Non-occlusive mesenteric ischaemia: a common disorder in gastroenterology and intensive care.

Non-occlusive mesenteric ischaemia is characterized by gastrointestinal ischaemia with normal vessels. In gastroenterology it is recognized as rare disease occasionally causing acute bowel infarction or ischaemic colitis. From intensive care literature this disorder is recognized as an early phenomenon during circulatory stress. This early mucosal ischaemia then leads to increased permeability, bacterial translocation, and further mucosal hypoperfusion. The damage is produced mainly during reperfusion following ischaemia with fresh inflow of oxygen and outflow of waste products into the systemic circulation. The mechanisms underlying non-occlusive mesenteric ischaemia include macrovascular vasoconstriction, hypoperfusion of the tips of the villi and shunting. It is very common in critically ill and perioperative patients, but also occurs in pancreatitis, renal failure and sepsis. Treatment options include aggressive fluid resuscitation and careful choice of vasoactive drugs. Control of reperfusion damage and new endothelin-antagonists are potentially useful new treatment options.