Synopsis
Recognise arterial embolic, arterial thrombotic, venous and non-occlusive mesenteric ischaemia before peritonitis, obtain immediate CT angiography despite a normal early lactate, and coordinate revascularisation, anticoagulation and bowel viability surgery.
- Severe abdominal pain out of proportion to early examination is the classic clue, but older, sedated or critically ill patients may present with delirium, diarrhoea, bleeding or unexplained organ failure.
- Arterial embolism is associated with atrial fibrillation or cardiac thrombus; arterial thrombosis with atherosclerosis; venous thrombosis with thrombophilia or inflammation; non-occlusive disease with low flow and vasoconstriction.
- A normal lactate, pH or D-dimer cannot exclude early bowel ischaemia; laboratory abnormalities often mark advanced disease.
Key red flags
Sudden severe diffuse pain with minimal early tenderness in a person with atrial fibrillation, recent infarction or embolic disease should trigger immediate CTA.
Investigation priorities
Acquire arterial and portal-venous phases urgently to identify arterial or venous occlusion, non-occlusive vasospasm, bowel viability and alternative pathology.
Management branches
Disproportionate pain or high-risk deterioration raises mesenteric ischaemia before peritonism.
- Use ABCDE, provide analgesia, obtain access and bloods, and call senior general and vascular surgery while requesting immediate CTA by name.
- Do not allow a normal lactate or unavailable creatinine to delay a life-saving scan; communicate cardiac, vascular and low-flow risks to radiology.
Key medicines
Unfractionated heparinTherapeutic intravenous bolus and infusion according to the local vascular protocol and coagulation monitoring, unless active bleeding or another contraindication exists.
Broad-spectrum intravenous antibioticsImmediate local intra-abdominal sepsis regimen with Gram-negative and anaerobic cover, adjusted for renal function and cultures.