Acute Colonic Pseudo-Obstruction (Ogilvie's Syndrome)
What Is It?
Acute colonic pseudo-obstruction (Ogilvie's syndrome) is a condition characterized by massive colonic dilatation (typically ≥9-10 cm) with signs and symptoms of intestinal obstruction, occurring in the absence of any mechanical obstructing lesion. 1, 2, 3
This condition predominantly affects elderly patients with serious underlying medical conditions or those who have recently undergone major surgery or trauma. 1, 4, 2
Pathophysiology
The underlying mechanism involves impaired colonic motility due to an imbalance in autonomic nervous system regulation, specifically affecting the parasympathetic and sympathetic innervation of the colon. 4, 5
Key Pathophysiologic Features:
Autonomic dysfunction: The condition arises from uncoordinated or attenuated intestinal muscle contractions due to disrupted neural control, with sympathetic overactivity or parasympathetic insufficiency playing central roles. 4, 5
Functional obstruction: Unlike mechanical obstruction, there is no physical blockage—the colon simply fails to propel its contents forward despite massive dilatation. 1, 5
Colonic distension without mechanical cause: The colon dilates massively (often >10 cm, sometimes >12 cm) without any anatomic obstruction, stricture, or transitional zone that would indicate a mechanical problem. 2, 3
Clinical Manifestations
Cardinal Presenting Features:
Abdominal distension: Massive, progressive abdominal distention is the hallmark finding. 1, 2, 5
Signs of intestinal obstruction: Patients present with symptoms mimicking mechanical bowel obstruction including nausea, vomiting, inability to pass stool or flatus, and colicky abdominal pain. 1, 5
Radiologic findings: Plain abdominal X-ray or CT scan demonstrates colonic dilatation ≥9-10 cm (average 12-13 cm in most series) without a mechanical transition point. 2, 3
Patient Demographics and Risk Factors:
Elderly population: Median age typically 64-67 years, with elderly and immobile patients comprising the majority of cases. 1, 2, 3
Post-surgical or post-trauma: Approximately 66% of cases occur following surgery (especially major orthopedic procedures like hip arthroplasty) or trauma. 4, 2
Severe medical illness: About 33% develop during acute severe medical conditions without preceding surgery. 2
Narcotic use: A significant proportion (63% in one series) receive intravenous narcotics prior to symptom development, as opioids inhibit colonic motility. 2
Associated Conditions and Triggers:
Medications: Anticholinergic drugs, narcotics, and other agents that inhibit intestinal motility are major contributors. 4, 5
Metabolic derangements: Electrolyte abnormalities (especially hypokalemia), diabetes mellitus, hyperparathyroidism. 4, 5
Neurologic conditions: Parkinson's disease and other disorders affecting autonomic function. 4
Comorbid burden: Patients typically have multiple serious underlying conditions (average Charlson Comorbidity Index of 3.2-3.4). 3
Clinical Course:
Variable severity: Can range from moderate distension responding to conservative measures to life-threatening colonic ischemia or perforation requiring emergency surgery. 2, 3
Complications: Include colonic ischemia, perforation (complication rate ~3.8% with interventions), and complications related to underlying severe comorbidities. 2, 3
Mortality: Overall hospital mortality ranges from 21% in older series, though more recent data suggests lower inpatient mortality when appropriately managed, with deaths typically related to underlying severe comorbidities rather than the pseudo-obstruction itself. 2, 3