ICU ·

Ogilvie syndrome (acute colonic pseudo-obstruction)

Also known as Acute colonic pseudo-obstruction (ACPO) · Ogilvie syndrome · Acute adynamic ileus of the colon · Colonic pseudo-obstruction · Non-mechanical colonic obstruction · Neostigmine-responsive colonic ileus · Caecal perforation risk (ACPO) · Percutaneous caecostomy · Ponec neostigmine trial · ASCRS ACPO guideline

Ogilvie syndrome (acute colonic pseudo-obstruction, ACPO) is massive colonic dilation WITHOUT mechanical obstruction, attributed to an imbalance in autonomic regulation of colonic motor function — excessive parasympathetic suppression or sympathetic stimulation — producing colonic atony, although the exact pathophysiology remains unclear. It is a disease of the hospitalised: precipitants include recent surgery (orthopaedic, cardiac, caesarean, abdominal), critical illness/sepsis, electrolyte disturbance, opioids and anticholinergics, immobility, retroperitoneal pathology, trauma, burns, and metabolic disease. Presentation is progressive, often painless, abdominal distension developing over several days with tympani, minimal or absent bowel sounds, and nausea; pain disproportionate to the picture or peritonism signals ischaemia or perforation. Diagnosis is clinical plus imaging: plain AXR (and confirmatory CT with contrast) showing caecal dilation, with explicit exclusion of mechanical obstruction. Perforation risk increases when caecal diameter exceeds 12 cm AND distension has been present for more than 6 days; mortality is approximately 40% once ischaemia or perforation occurs. Management is staged: conservative measures first (bowel rest, NG and rectal tubes, electrolyte correction, stopping causative drugs, mobilisation); if refractory, neostigmine 2-2.5 mg IV (2.0 mg in the pivotal randomised trial, 91% response vs 0% placebo) with continuous cardiac monitoring and atropine available; colonoscopic decompression for neostigmine failure or contraindication (pooled first-session success 78.8%, overall 91.5%); surgery for peritonitis, ischaemia or perforation.