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Mesenteric Ischemia

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Mesenteric Ischemia, Acute Mesenteric Ischemia, Mesenteric Infarction, Colonic Ischemia, Intestinal Ischemia, Colonic Vasculitis, Ischemic Colitis

  • Pathophysiology
  1. Watershed blood supply areas most often affected
    1. Splenic flexure
    2. Rectosigmoid
  • Epidemiology
  1. Uncommon condition (but requires high index suspicion)
    1. Accounts for 1% of Acute Abdominal Pain admits
  2. More common in elderly
  3. Males more commonly affected
  • Risk Factors
  1. Atherosclerosis
  2. Myocardial Infarction (recent)
  3. Atrial fiibrillation
  4. Dilated Cardiomyopathy
  5. Hypovolemia
  6. Valvular Disease
  7. Advanced age
  8. Intra-Abdominal Cancer
  9. Rapid weight loss (e.g. Anorexia)
    1. Results in decreased fat between duodenum and superior Mesenteric Artery
    2. Ischemia results from duodenal compression of the superior Mesenteric Artery
  • Causes
  • Primary Acute Mesenteric Ischemia (intravascular)
  • Causes
  • Secondary Mesenteric Ischemia (compression)
  1. Adhesions
  2. Herniation
  3. Volvulus
  4. Intussusception
  5. Tumor
  6. Trauma
  7. Retroperitoneal fibrosis
  • Symptoms
  1. Abdominal Pain
    1. Severe and out of proportion to exam
    2. Pain is poorly localized
    3. Left Lower Quadrant abdominal cramping may occur
  2. Gastroenteritis-type symptoms (one third of cases)
    1. Diarrhea
      1. Superior Mesenteric Artery Embolism
      2. Superior Mesenteric Artery Thrombosis
    2. Nausea and Vomiting
      1. Superior Mesenteric Artery Embolism
      2. Mesenteric Venous Thrombosis
  • Labs
  • Diagnosis
  1. Complete Blood Count (CBC)
    1. Leukocytosis >15,000 with Left Shift is common
  2. Serum Phosphate Level
    1. Increases within 4 hours (75%)
  3. Labs abnormal if bowel perforation occurs
    1. Arterial Blood Gas (ABG) with Metabolic Acidosis
    2. Serum Amylase increased
    3. Serum lactate increased
  • Labs
  • Other
  1. Basic metabolic panel (e.g. Chem8)
    1. Electrolytes
    2. Renal Function tests
      1. Blood Urea Nitrogen (BUN)
      2. Creatinine
  2. Liver Function Tests (LFT)
    1. AST increased
    2. Lactate Dehydrogenase (LDH)
    3. Creatine Phosphokinase (CK-MM) Increased
  3. ProTime
  4. Partial Thromboplastin Time (PTT)
  5. Fibrin Split Products (FSP)
  6. Fibrinogen
  7. Blood Culture
  8. Urinalysis
  9. Type and Cross
  • Radiology
  1. Abdominal XRay (KUB)
    1. Findings suggestive of Mesenteric Ischemia (20-60%)
      1. Adynamic Ileus
      2. Thumb printing of bowel wall
      3. Bowel wall thickening
      4. Air in bowel wall or Portal Vein
    2. Other conditions identified
      1. Small Bowel Obstruction
        1. Air-fluid levels
        2. Fixed dilated loops of bowel
      2. Volvulus
      3. Viscus perforation
  2. CT Abdomen
    1. Bowel wall thickening (edema, Hemorrhage)
    2. Bowel wall gas
  3. Angiography (gold standard)
    1. Order with low threshold
    2. Rapid diagnosis is critical to survival
  • Management
  1. Immediate Surgical Consultation
  2. See specific causes above
  3. Aggressive Intravenous Fluid hydration
  4. Adnminister Supplemental Oxygen
  5. Nasogastric suction (NG tube)
  6. Discontinue Vasoconstricting medications
    1. Discontinue Pressors
    2. Discontinue Digitalis
    3. Discontinue Beta Blockers
  7. Stabilize concurrent cardiovascular disease
    1. Congestive Heart Failure
    2. Cardiac arrhythmia
  8. Antibiotics to cover Gram-Negative Bacteria
  • Prognosis
  1. Mortality: up to 85%