Intestinal Ischaemia Flashcards
What is meant by mesenteric ischemia?
Umbrella term for conditions resulting from reduced blood flow to the intestines
Can lead to bowel tissue damage and necrosis if untreated.
What conditions are included in the mesenteric ischemia category?
Acute mesenteric ischemia
Chronic mesenteric ischemia
Ischemic colitis.
What is acute mesenteric ischemia?
What are the different causes?
Sudden onset
Life threatning
Includes:
Arterial embolism - often from AF in the heart
Arterial thrombosis - progressive atherosclerosis then rupture lead to vessel occlusion
Mesenteric venous thrombosis - clot in veins
Non-occlusive mesenteric ischemia - hypoperfusion due to low cardiac output (critically ill patients)
What is chronic mesenteric ischemia?
How does it often present?
Gradual development of insufficient blood/oxygen supply to the bowel often due to gradual development of atherosclerosis
Causes postprandial pain “intestinal angina” and weight loss due to fear of eating.
Primarly affects older patients with cardiovascular risk factors such as smoking, hypertension and diabetes
What is ischemic colitis?
Reduces blood supply to the colon (large intestine), most commonly the left colon (watershed area near the splenic flexure)
Frequently caused by hypoperfusion, arterial or venous occlusion or trauma.
Can resolve with supportive care but severe cases may require surgical intervention.
What are the different watershed areas in the bowel and why is this relevant to ischemic colitis?
The splenic flexure - Griffiths point - frequent site of ischemic colitis
The rectosigmoid junction - Sudeks points - common ischemia
watershed area - area of anastomosis, high risk of hypoperfusion when blood pressure drops.
What is the basic pathophysiology of mesenteric ischemia?
Reduced blood flow to the intestines, leading to ischemic injury and potential bowel necrosis.
What is the basic pathophysiology of ischemic colitis?
Blood flow to the colon is compromised, often due to transient factors like low blood pressure, atheroma or drug effects e.g (vasopressors)
What is the clinical presentation in acute mesenteric ischemia?
Sudden onset of severe abdominal pain - out of proportion to physical exam findings
Nausea, vomiting, diarrhea and bloody stools
Late signs - peritonitis (guarding, rebound tenderness), indicating bowel necrosis.
What is the clinical presentation of chronic mesenteric ischemia?
Postprandial pain (30-60mins) after eating
Weight loss due to food aversion
Vague tenderness but generally disproportional to the pain described
What is the clinical presentation of ischemic colitis?
Left sides abdominal pain, often with bloody diarrhea
Nausea, vomiting and sometimes fever
Less severe than AMI - often transient and resolves with supportive care
In severe cases, signs of peritonitis ot speis indicate full thickness ischemia or perforation.
In the ED what presentation should create high suspicion of a bowel ischemia?
Acute mesenteric ischemia - abdo pain out of proportion of exam findings
Patients with atrial fibrillation, recent MI or severe hypotension.
What are some key risk factors for the different causes of bowel ischemia?
Arterial embolism - AF, endocarditis, valvular heart disease
Arterial thrombus - atherosclerosis, dehydration, heart failure
Venous thrombosis - hypercoagulable states, portal hypertension, trauma
Ishcemic colitis - elderly, hypotension, drug use (vasopressors, cocaine), post surgical complications.
How should you diagnose an intestinal ischemia?
CT angiography - gold standard for acute
Abdominal CT - with IV contrast, rule out differential and find ischemic colitis
Lactate elevation and leukocytosis - suggest ischemia but are non-specific
What is the management for intestinal ischemia?
For AMI - immediate surgical interventional radiology consultation for revascularization or bowel resection
For IC - supportive care (bowel rest, fluids, broad spectrum antibiotics), surg if necrosis or perforation
