Acute Colonic Pseudo-obstruction (Ogilvie Syndrome)
Synonyms of Ogilvie syndrome
- acute colonic pseudo-obstruction
- colonic pseudo-obstruction
- Ogilvie’s syndrome
Ogilvie syndrome is a rare, acquired disorder characterized by abnormalities affecting the involuntary, rhythmic muscular contractions (peristalsis) within the colon. Peristalsis propels food and other material through the digestive system through the coordination of muscles, nerves and hormones. The colon is often significantly widened (dilated).
Spontaneous massive dilation of the cecum and proximal colon may occur in a number of different settings in hospitalized patients. Progressive cecal dilation may lead to spontaneous perforation with dire consequences. The risk of perforation correlates poorly with absolute cecal size and duration of colonic distention. Early detection and management are important to reduce morbidity and mortality.
Colonic pseudo-obstruction is most commonly detected in postsurgical patients (mean 3–5 days), after trauma, and in medical patients with respiratory failure, metabolic imbalance, malignancy, myocardial infarction, heart failure, pancreatitis, or a recent neurologic event (stroke, subarachnoid hemorrhage, trauma). Liberal use of opioids or anticholinergic agents may precipitate colonic pseudo-obstruction in susceptible patients. It may also occur as a manifestation of colonic ischemia.
Signs & Symptoms
The symptoms and severity of Ogilvie syndrome can vary greatly from one person to another. Ogilvie syndrome can potentially cause serious, life-threatening complications. The disorder most often occurs in hospitalized or institutionalized patients who have an underlying illness or have recently undergone surgery.
Common symptoms of Ogilvie syndrome include abdominal swelling (distention) and bloating, abdominal pain, nausea and vomiting. Some individuals have a history of chronic, sometimes severe constipation. Abdominal distention usually develops over several days, but can potentially develop rapidly within a 24-hour period. Colonic distention can be massive. Additional symptoms that can occur including fever, marked abdominal tenderness and an abnormal increase in the number of white blood cells (leukocytosis) often due to infection. Fever, marked abdominal tenderness, and leukocytosis are more common individuals with perforation or ischemia, but can occur in the absence of these conditions.
Distention of the colon in Ogilvie syndrome can potentially lead to serious, life-threatening complications including the formation of a hole in the wall of the colon (perforation) or lack of blood flow (ischemia) to the colon. Perforation may allow the contents of the colon to spill out into the abdominal cavity. A perforated bowel can cause intense abdominal pain, fever, and sepsis, a severe blood infection. The cecum, the large pouch that marks the beginning of the large intestines, is the area most often where the greatest dilation occurs and consequently is most at risk of perforation. Perforation in Ogilvie syndrome is rare developing in only 1-3 percent of affected individuals.
Ischemic bowel results in tissue damage or death in the affected portion of the bowel. Individuals with a perforated or ischemic bowel have a greater incidence of fever and may have signs of inflammation of the peritoneum (peritonitis). The peritoneum is the thin tissue that lines the inside of the abdominal wall and covers most of the abdominal organs.
A diagnosis of Ogilvie syndrome is made based upon identification of characteristic symptoms, a detailed patient history, a thorough clinical evaluation and a variety of specialized tests to rule out other conditions or identify underlying causes.
Ogilvie syndrome is virtually indistinguishable from mechanical obstruction based solely on signs and symptoms. X-ray examination of the colon will be performed to rule out mechanical obstruction. Plain abdominal films (radiographs) can reveal an abnormally expanded (dilated) colon. Plain abdominal radiographs can also reveal dilation and abnormal air-fluid levels in the small bowel, both of which are indicative of intestinal obstruction.
A water-soluble enema or computed tomography should be performed to rule out mechanical obstruction in cases where gas and distention does not occur throughout the entire colon. A water-soluble enema is a procedure that allows a physician to evaluate the large bowel. During the exam, a soft, thin tube is inserted into the anal passage. Dye is injected into the tube and x-rays will be taken. The dye will show the outline of the large bowel on the x-ray, revealing mechanical obstruction if present. During CT scanning, a computer and x-rays are used to create a film showing cross-sectional images of certain tissue structures such as the colon.
Colonic pseudo-obstruction should be distinguished from distal colonic mechanical obstruction (as above) and toxic megacolon, which is acute dilation of the colon due to inflammation (inflammatory bowel disease) or infection (C difficile–associated colitis, CMV). Patients with toxic megacolon manifest fever; dehydration; significant abdominal pain; leukocytosis; and diarrhea, which is often bloody.
Conservative treatment is the appropriate first step for patients with no or minimal abdominal tenderness, no fever, no leukocytosis, and a cecal diameter smaller than 12 cm. The underlying illness is treated appropriately. A nasogastric tube and a rectal tube should be placed. Patients should be ambulated or periodically rolled from side to side and to the knee-chest position in an effort to promote expulsion of colonic gas. All drugs that reduce intestinal motility, such as opioids, anticholinergics, and calcium channel blockers, should be discontinued if possible. Enemas may be administered judiciously if large amounts of stool are evident on radiography. Oral laxatives are not helpful and may cause perforation, pain, or electrolyte abnormalities.
Conservative treatment is successful in over 80% of cases within 1–2 days. Patients must be watched for signs of worsening distention or abdominal tenderness. Cecal size should be assessed by abdominal radiographs every 12 hours. Intervention should be considered in patients with any of the following:
- no improvement or clinical deterioration after 24–48 hours of conservative therapy;
- cecal dilation greater than 10 cm for a prolonged period (more than 3–4 days);
- patients with cecal dilation greater than 12 cm.
Neostigmine injection should be given unless contraindicated. A single dose (2 mg intravenously) results in rapid (within 30 minutes) colonic decompression in 75–90% of patients. Cardiac monitoring during neostigmine infusion is indicated for possible bradycardia that may require atropine administration.
Colonoscopic decompression is indicated in patients who fail to respond to neostigmine. Colonic decompression with aspiration of air or placement of a decompression tube is successful in 70% of patients. However, the procedure is technically difficult in an unprepared bowel and has been associated with perforations in the distended colon. Dilation recurs in up to 50% of patients. In patients in whom colonoscopy is unsuccessful, a tube cecostomy can be created through a small laparotomy or with percutaneous radiologically guided placement.