Colonic Pseudo-obstruction, Acute (Ogilvie Syndrome)

Essentials of Diagnosis

• Severe abdominal distention

• Massive dilation of cecum or right colon

• Arises in postoperative state or with severe medical illness

• May be precipitated by electrolyte imbalances, medications

• Absent to mild abdominal pain; minimal tenderness

General Considerations

• Spontaneous massive dilation of the cecum and proximal colon in hospitalized patients

• Progressive cecal dilation may lead to ischemia and spontaneous perforation

• Etiology unknown

• Associated conditions

  • Trauma

  • Respiratory failure

  • Malignancy

  • Myocardial infarction or heart failure

  • Pancreatitis

  • Stroke or subarachnoid hemorrhage

  • Ischemic colitis

  • Use of drugs, eg, opioids, anticholinergics

Demographics

• Occurs mainly in hospitalized patients with recent trauma, surgery (especially cardiothoracic), or severe medical illness

• May be precipitated by electrolyte imbalance or opioids

Symptoms and Signs

• Sometimes asymptomatic

• Constant but mild abdominal pain

• Nausea and vomiting

• Abdominal distention

• Bowel movements may be absent; however, up to 40% of patients continue to pass flatus or stool

• Abdominal tenderness with some degree of guarding or rebound tenderness; however, signs of peritonitis absent unless perforation has occurred

• Bowel sounds may be normal or decreased

• Fever suggests colonic perforation

Differential Diagnosis

• Mechanical colonic obstruction, eg, malignancy, diverticulitis, volvulus, fecal impaction

• Toxic megacolon due to inflammatory bowel disease or Clostridioides difficile colitis, cytomegalovirus

Laboratory Tests

• Obtain complete blood count, serum sodium, potassium, magnesium, phosphorus, and calcium

• Leukocytosis suggests colonic ischemia or perforation

Imaging Studies

• Plain radiographs demonstrate colonic dilation, usually cecum and proximal colon

• Varying amounts of small intestinal dilation and air-fluid levels

• Cecal diameter > 10–12 cm associated with increased risk of colonic perforation

• A CT scan should generally be obtained to exclude a distal colonic mechanical obstruction due to malignancy, volvulus, or fecal impaction

Medications

• Discontinue opioids, anticholinergics, and calcium channel blockers, if possible

• Correct electrolyte abnormalities

• Oral laxatives are not helpful and may cause perforation

• Neostigmine 2 mg intravenously as a single dose results in rapid (within 30 minutes) colonic decompression in 75–90% and should be considered for following patients:

  • No improvement or clinical deterioration after 24–48 hours of conservative treatment

  • Cecal dilation > 12 cm

  • Cecal dilation > 10 cm for prolonged period (3–4 days)

Therapeutic Procedures

• Treat underlying illness

• Conservative treatment is recommended if no or minimal abdominal tenderness, no fever, no leukocytosis, and a cecal diameter < 12 cm

  • Place a nasogastric tube and a rectal tube

  • Ambulate patients, or roll periodically from side to side and to knee-chest position

  • Judicious administration of enemas if large amounts of stool on radiography

  • Conservative treatment successful in > 80%

• Colonoscopic decompression in selected patients who do not respond to neostigmine, successful in up to 70%; dilation recurs in up to 50%

Surgery

• In patients in whom colonoscopy is unsuccessful, a tube cecostomy placed through a small laparotomy or percutaneously with radiologic guidance can decompress the colon

Follow-Up

• Watch for signs of worsening distention or abdominal tenderness

• Assess cecal size by abdominal radiographs every 12 hours

• Cardiac monitoring after neostigmine for possible bradycardia that may require atropine administration

Complications

• Colonic perforation or ischemia

Prognosis

• Prognosis related to the underlying illness

• With aggressive therapy, perforation unusual

When to Refer

• Failure to improve within 24–48 hours of conservative therapy

• Cecal size > 12 cm

• Signs of perforation

When to Admit

• Usually occurs in hospitalized patients