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Adynamic Ileus

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Adynamic Ileus, Paralytic Ileus, Adynamic Bowel Obstruction, Functional Bowel Obstruction, Neurogenic Bowel Obstruction

  • See Also
  1. Bowel Pseudoobstruction (Ogilvie Syndrome)
  • Pathophysiology
  1. Transient intestinal dysfunction and dysmotility or paralysis of intestinal motility without a physical blockage
  2. May affect the Stomach, Small Bowel or colon (contrast with Small Bowel Obstruction, which presents in similar manner)
  • Causes
  1. Abdominal Trauma
  2. Abdominal surgery (i.e. laparatomy)
    1. Onset typically 3-5 days after surgery
    2. Return of function by 24 hours for Small Bowel, 48 hours for Stomach, 72 hours for colon
  3. Serum Electrolyte abnormality
    1. Hypokalemia
    2. Hyponatremia
    3. Hypomagnesemia
    4. Hypermagensemia
  4. Infectious, Inflammatory or irritation (bile, blood)
    1. Intrathoracic
      1. Pneumonia
      2. Lower lobe Rib Fractures
      3. Myocardial Infarction
    2. Intrapelvic (e.g. Pelvic Inflammatory Disease)
    3. Intraabdominal
      1. Appendicitis
      2. Diverticulitis
      3. Nephrolithiasis
      4. Cholecystitis
      5. Pancreatitis
      6. Perforated Duodenal Ulcer
  5. Intestinal Ischemia
    1. Mesenteric embolism, ischemia or thrombosis
  6. Skeletal injury
    1. Rib Fracture
    2. Vertebral Fracture (e.g. lumbar compression Fracture)
  7. Medications
    1. Opioids
    2. Phenothiazines
    3. Diltiazem or Verapamil
    4. Clozapine
    5. Anticholinergic Medications (e.g. Tricyclic Antidepressants)
  • Risk Factors
  1. Advanced Age
  2. Prolonged bedrest
  3. Male gender
  4. Positive Fluid Balance (esp. excessive intraoperative hydration)
  • Symptoms
  1. Abdominal Distention
  2. Nausea and Vomiting are variably present
  3. Generalized abdominal discomfort
    1. Colicky, cramping pain of Mechanical Ileus is usually absent
  4. Flatus and Diarrhea may still be passed
  • Signs
  1. Quiet bowel sounds
  2. Abdominal Distention
  • Differential Diagnosis
  1. Mechanical Ileus
  2. Bowel Pseudoobstruction
  3. See Ileus for diagnostic approach
  • Radiology
  • Plain Flat and Upright Abdominal XRay
  1. Contrast with Mechanical Ileus
  2. Less prominent air fluid levels
  3. Generalized involvement of entire GI Tract
  4. Air filled bowel loops tend not to be distended
  • Radiology
  • Refractory ileus course
  1. Indicated to evaluate for Mechanical Ileus
  2. Upper GI series and Small Bowel follow through
    1. May be diagnostic and therepeutic
    2. Use gastrograffin instead of barium
      1. Barium may further obstruct bowel lumen
      2. Gastrograffin may stimulate bowel motility
    3. Decompress Stomach with Nasogastric Tube
    4. Instill gastrograffin via Nasogastric Tube
  3. CT Abdomen
  • Management
  1. Initial
    1. Limit or eliminate oral intake
    2. Avoid all medications that inhibit bowel motility (e.g. Anticholinergic Medications)
    3. Intravenous Fluid Replacement
    4. Correct Electrolyte abnormalities (e.g. Hypokalemia)
    5. Consider Nasogastric Tube placement
  2. Refractory Management (anecdotal evidence only)
    1. Consider Reglan 0.1 mg/kg/dose up to 10 mg (contraindicated in Small Bowel Obstruction)
    2. Consider lower bowel stimulation (e.g. Fleets Enema)
  • Course
  1. Post-operative ileus resolves within 24-48 hours
  • References
  1. Han (2022) Crit Dec Emerg Med 36(12): 4-10
  2. Torrey in Marx (2002) Rosen's Emergency Med, p. 1283-7
  3. Townsend (2001) Sabiston Surgery, p. 883-8
  4. Turnage in Feldman (1998) Sleisenger GI, p. 1799-804