Non-mechanical decrease or stoppage of flow of intestinal contents that is often the result of a neuroimmune interaction that consists of the early neurogenic phase (autonomic nervous system) and the inflammatory phase (immune system).
Risk factors: critically ill patients, s/p abdominal or retroperitoneal surgery, or perioperative complications (pneumonia or abscess).
Other risk factors: opioid use, intra-abdominal inflammation/infection, bleeding, hypokalemia, and delayed enteral nutrition.
Presentation
Abdominal distention, bloating, N/V, inability to pass flatus, sparse/absent bowel sounds, often with slower onset than seen in a mechanical bowel obstruction
Pain is often diffuse, persistent, and w/o peritoneal signs
Evaluation
Plain abdominal films: supine and upright films may show dilated small bowel loops, air in the colon and rectum without a transition point.
If plain films are non-diagnostic, CT abdomen and pelvis with oral contrast can help identify presence of transition point.
BMP to evaluate for electrolyte abnormalities.
Management
Treating the underlying cause, bowel rest, IV fluids, +/- NG decompression, decrease opioids, ambulation and monitor and replete electrolytes.
Small bowel follow-through with gastrografin or water-soluble contrast does not help ileus.
