Ileus, Acute Paralytic

Essentials of Diagnosis

• Precipitating factors

  • Surgery

  • Peritonitis

  • Electrolyte abnormalities

  • Severe medical illness

• Nausea, vomiting, obstipation, distention

• Minimal abdominal tenderness; decreased bowel sounds

• Plain abdominal radiography with gas and fluid distention in small and large bowel

General Considerations

• Neurogenic failure or loss of peristalsis in the intestine in the absence of any mechanical obstruction

• Common in hospitalized patients as a result of the following

  • Intra-abdominal processes, such as

    • Recent gastrointestinal or abdominal surgery

    • Peritoneal irritation (peritonitis, pancreatitis, ruptured viscus, hemorrhage)

  • Severe medical illness, such as

    • Pneumonia

    • Respiratory failure requiring intubation

    • Sepsis or severe infections

    • Uremia

    • Diabetic ketoacidosis

    • Electrolyte abnormalities (hypokalemia, hypercalcemia, hypomagnesemia, hypophosphatemia)

  • Medications, such as

    • Opioids

    • Anticholinergics

    • Phenothiazines

• Postoperative ileus is reduced by

  • Use of patient-controlled or epidural analgesia

  • Avoidance of intravenous opioids

  • Early ambulation

  • Gum chewing

  • Initiation of a clear liquid diet

Symptoms and Signs

• Mild diffuse, continuous abdominal discomfort

• Nausea and vomiting

• Generalized abdominal distention

• Minimal abdominal tenderness

• No signs of peritoneal irritation

• Bowel sounds are diminished to absent

Differential Diagnosis

• Mechanical obstruction of small intestine or proximal colon, eg, adhesions, volvulus, Crohn disease

• Chronic intestinal pseudo-obstruction

Laboratory Tests

• Obtain serum electrolytes, potassium, magnesium, phosphorus, and calcium

Imaging Studies

• Plain abdominal radiography: air-fluid levels, distended gas-filled loops of small and large intestine

• Limited barium small bowel series or a CT scan can help exclude mechanical obstruction

Medications

• Alvimopan

  • A peripherally acting mu-opioid receptor antagonist with limited absorption or systemic activity that reverses opioid-induced inhibition of intestinal motility

  • Reduces time to first flatus, bowel movement, solid meal, and hospital discharge in postoperative patients

  • May be considered in patients undergoing partial large or small bowel resection when postoperative opioid therapy is anticipated

Therapeutic Procedures

• Treat underlying primary medical or surgical illness

• Nasogastric suction for discomfort or vomiting

• Restrict oral intake, administer intravenous fluids

• Liberalize diet gradually as bowel function returns

• Minimize anticholinergic and opioid medications

• Severe or prolonged ileus requires nasogastric suction and infusion of parenteral fluids and electrolytes

Follow-Up

• Return of bowel function usually heralded by return of appetite and passage of flatus

• Serial plain film radiography and/or abdominal CT warranted for persistent or worsening symptoms to distinguish from mechanical obstruction

Prognosis

• Ileus usually resolves within 48–72 h

• Following surgery, small intestinal motility normalizes first (within hours), followed by stomach (24–48 h) and colon (48–72 h)

When to Refer

• Persistent ileus lasting more than 3–5 days warrants further evaluation for underlying cause and to exclude mechanical obstruction

When to Admit

• All patients with ileus require admission for intravenous fluids