What is the recommended management of adynamic ileus?

Management of Adynamic Ileus

Begin with immediate bowel rest (NPO status), intravenous isotonic crystalloid resuscitation, and aggressive correction of electrolyte abnormalities—particularly potassium and magnesium—while simultaneously discontinuing all medications that impair gut motility, especially opioids and anticholinergics. 1, 2, 3

Initial Resuscitation and Stabilization

Fluid Management

• Administer isotonic intravenous fluids (lactated Ringer's or normal saline) to restore euvolemia while strictly avoiding fluid overload 1, 2
• Target weight gain of less than 3 kg by day three to prevent intestinal edema that worsens ileus 1
• Avoid 0.9% saline due to risk of salt and fluid overload 1
• Continue IV rehydration until heart rate, peripheral perfusion, and mental status normalize 2

Electrolyte Correction

• Correct hypokalemia aggressively, but first address sodium depletion and hypomagnesemia, as low potassium is typically secondary to hyperaldosteronism from sodium depletion 2
• Administer intravenous magnesium sulfate initially for hypomagnesemia, then transition to oral magnesium oxide 2
• Monitor serum creatinine, potassium, and magnesium every 1-2 days initially 2

Gastrointestinal Decompression

• Place a nasogastric tube only in patients with severe abdominal distention, active vomiting, or aspiration risk 1, 2
• Remove the nasogastric tube as early as possible—prolonged decompression paradoxically extends ileus duration rather than shortening it 1, 2

Medication Management

Immediate Discontinuation

• Stop all opioid analgesics immediately, as they directly inhibit gastrointestinal motility and are a primary modifiable cause of prolonged ileus 1, 2
• Discontinue anticholinergics, cyclizine, antidepressants, antispasmodics, phenothiazines, and haloperidol 4, 2

Opioid-Sparing Analgesia

• Implement mid-thoracic epidural analgesia with local anesthetic as the single most effective intervention for preventing and treating ileus 1, 2
• Use multimodal analgesia with NSAIDs and acetaminophen as alternatives 1
• Consider methylnaltrexone 0.15 mg/kg subcutaneously every other day for opioid-induced constipation contributing to ileus (contraindicated in mechanical obstruction) 1, 2

Pharmacological Interventions

Once Oral Intake Resumes

• Administer bisacodyl 10-15 mg orally once to three times daily 1, 2
• Give oral magnesium oxide to promote bowel function 1, 2
• Consider loperamide 2-8 mg before meals if high-output diarrhea is a concern 1

For Persistent Ileus

• Consider metoclopramide 10-20 mg orally four times daily as a prokinetic agent, though evidence for effectiveness is limited 1, 2
• For colonic pseudo-obstruction specifically, neostigmine may be used for pharmacologic colonic decompression 3, 5
• Consider erythromycin 900 mg/day if absent or impaired antroduodenal migrating complexes are documented, though tachyphylaxis occurs 4
• Octreotide 50-100 μg subcutaneously once or twice daily may be dramatically beneficial when other treatments fail, with effect apparent within 48 hours 4

For Bacterial Overgrowth

• If bacterial overgrowth is suspected (cachexia, diarrhea), use rifaximin as first choice, or rotate antibiotics including amoxicillin-clavulanic acid, metronidazole, ciprofloxacin, or doxycycline every 2-6 weeks 4

Early Recovery Measures

Mobilization and Nutrition

• Begin ambulation immediately once the patient's condition allows—early mobilization stimulates bowel function 1, 2
• Remove urinary catheter within 24 hours to facilitate mobilization 1
• Encourage early oral intake with small portions once bowel sounds return; do not delay feeding based solely on absence of bowel sounds 1
• Start with clear liquids and advance to solids within 4 hours if tolerated 1
• Implement chewing gum as soon as the patient is awake to stimulate bowel function through cephalic-vagal stimulation 1, 2

Nutritional Support for Prolonged Ileus

• If oral intake will be inadequate for more than 7 days, initiate early tube feeding 1
• If enteral feeding is contraindicated due to intestinal obstruction, sepsis, ischemia, high-output fistulae, or severe hemorrhage, provide early parenteral nutrition 1

Management of Complications

Intra-Abdominal Hypertension

• Optimize sedation and analgesia to reduce abdominal wall tension 2
• Consider short-term neuromuscular blockade as a temporizing measure if intra-abdominal pressure exceeds 20-25 mmHg 2, 5
• Implement fluid-balance protocol after initial resuscitation to avoid positive cumulative fluid balance 2
• For abdominal compartment syndrome, decompressive laparotomy with temporary abdominal closure is the therapy of choice 5

Colonic Pseudo-Obstruction

• Place a rectal tube for colonic decompression if significant colonic dilation is present 2
• Consider colonoscopic decompression for refractory cases 3, 5

Critical Pitfalls to Avoid

• Do not continue opioids without switching to opioid-sparing alternatives or peripheral opioid antagonists 1
• Do not maintain prolonged nasogastric decompression unless severe distention, vomiting, or aspiration risk persists 1, 2
• Do not continue aggressive IV fluid administration beyond euvolemia—fluid overload is a major preventable cause of prolonged ileus 1, 2
• Do not delay mobilization or oral intake based solely on absence of bowel sounds 1
• Do not use metoclopramide long-term due to risk of irreversible tardive dyskinesia, especially in elderly patients 4

Monitoring Parameters

• Assess for return of bowel function: passage of flatus, bowel sounds, tolerance of oral intake 2
• Monitor vital signs, abdominal distension, and hydration status every 2-4 hours initially 2
• Check serum electrolytes every 24-48 hours in severe cases 2
• Obtain daily abdominal radiography if colonic dilatation is present 2