A 65-Year-Old Man With a Hugely Distended Abdomen

Prashanth Rawla, MD; Jeffrey Pradeep Raj, MD


October 24, 2019


An acute colonic pseudo-obstruction (ACPO) is also often referred to by its historical eponym, Ogilvie syndrome. It is characterized by severe colonic distension in the absence of any mechanical obstruction.[1] The exact pathophysiology of ACPO is not clearly elucidated.[2] However, a hypothesis suggests that an imbalance in the autonomic nervous system leads to either increased sympathetic tone, decreased parasympathetic tone, or both combined.[3]

ACPO has many causes; trauma, serious infections, cardiac diseases (eg, myocardial infarction, congestive heart failure), recent surgery, electrolyte imbalance, and severe hypothyroidism are among the more common causes.[4] This patient is an older man with multiple comorbidities and distended intestines on radiologic imaging studies but with no clinical evidence of mechanical obstruction. Thus, his condition fits well with a diagnosis of ACPO.

The incidence of ACPO is approximately 100 per 100,000 cases of hospital admissions, although the condition may be underreported.[5] The prevalence was 0.29% in a study that involved 2703 critically ill patients with burns.[6] In another study conducted among 10,468 patients who underwent hip arthroplasty, the prevalence of ACPO during the postoperative period was once again 0.29%.[7] However, the prevalence may be much higher among patients undergoing major orthopedic surgery, with reported rates of 0.65%-1.3%.[8] Approximately 95% of patients have medical or surgical comorbidities; the remaining cases of ACPO are idiopathic[9] with a male to female ratio of 1.5 to 1.[10] The condition usually affects older people in their sixth decade of life[10]; however, recent studies have shown a rise in the mean age to the seventh or eighth decade of life.[7,11]

Patients with ACPO typically have obstructive symptoms that include nausea, vomiting, and abdominal pain. However, this differs from mechanical obstruction by the fact that nearly 40%-50% of patients continue to pass flatus.[12] Upon examination, almost all patients have a distended abdomen of sudden onset and a progressive course, abdominal tenderness, and an empty rectum upon digital examination.[13] No major differences are noted between the symptoms of patients with ACPO and patients with ischemic bowel or perforated bowel except for a higher incidence of fever among patients with the latter conditions.[10] Thus, besides the important masquerades (ie, mechanical intestinal obstruction due to any cause), bowel ischemia, and perforation, other differential diagnoses are also noted. These include acute/chronic/toxic megacolon, Hirschsprung disease, diverticulitis, acute/chronic mesenteric ischemia, and tumors.[14]


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