What is the immediate management for a patient with suspected paralytic (adynamic) abdominal obstruction?

Immediate Management of Suspected Paralytic Ileus

Begin immediate supportive treatment with intravenous crystalloid resuscitation, nasogastric tube decompression, correction of electrolyte abnormalities (especially potassium), discontinuation of medications that impair motility, and early mobilization, while avoiding oral contrast agents and prokinetics in complete obstruction. 1, 2, 3

Initial Resuscitation and Supportive Care

The cornerstone of management for paralytic (adynamic) ileus is aggressive supportive therapy initiated immediately upon suspicion:

• Start IV crystalloid resuscitation to correct hypovolemia from third-spacing of fluids into the bowel lumen and prevent systemic complications including renal injury 1, 3, 4
• Insert nasogastric tube for gastric decompression to prevent aspiration pneumonia and reduce abdominal distension 1, 3
• Place Foley catheter to monitor urine output and assess adequacy of resuscitation 1
• Maintain strict NPO status (nothing by mouth) until bowel function returns 2, 3
• Administer antiemetics to control nausea and vomiting 1, 5

Critical Laboratory Corrections

Electrolyte abnormalities are both a cause and consequence of paralytic ileus and must be corrected aggressively:

• Check and correct potassium levels, as hypokalemia is frequently found and perpetuates ileus 1
• Obtain complete metabolic panel including electrolytes, BUN/creatinine, and lactate 1, 2, 3
• Monitor for elevated lactate which may indicate evolving ischemia or bacterial translocation 1, 4
• Assess CBC and CRP as marked leukocytosis >10,000/mm³ or CRP >75 may indicate peritonitis requiring surgical intervention 1

Medication Review and Discontinuation

A critical but often overlooked step is identifying and stopping medications that impair peristalsis:

• Review and discontinue opioids when possible, as they are a major cause of adynamic ileus 2, 6, 5
• Stop anticholinergic medications that inhibit intestinal motility 6, 5
• Avoid prokinetic agents in complete obstruction, though they may benefit partial obstruction 3, 5

Diagnostic Imaging to Exclude Mechanical Obstruction

The most important immediate decision is distinguishing paralytic ileus from mechanical obstruction, as management differs dramatically:

• CT abdomen/pelvis with IV contrast is the diagnostic test of choice with >90% accuracy for distinguishing mechanical obstruction from adynamic ileus 7, 1, 2, 8
• Do NOT give oral contrast in suspected obstruction as it delays diagnosis, increases patient discomfort, risks aspiration, and can mask bowel wall enhancement patterns indicating ischemia 7, 1
• Plain abdominal radiographs have limited value with only 50-60% sensitivity and 20-30% inconclusive results 1, 3
• CT findings in paralytic ileus include diffuse small and large bowel dilatation without a transition point, unlike mechanical obstruction which shows a discrete transition zone 8

Monitoring for Complications

Paralytic ileus can progress to life-threatening complications requiring urgent intervention:

• Monitor intra-abdominal pressure as ileus-induced bowel dilatation can cause intra-abdominal hypertension (IAP >20-25 mmHg) leading to abdominal compartment syndrome with multiorgan failure 4
• Watch for signs of bacterial translocation including fever, worsening leukocytosis, and systemic inflammatory response syndrome from intestinal bacterial overgrowth 4
• Assess for bowel ischemia which can develop from increased intraluminal pressure and gut wall distension 4, 9

Specific Therapeutic Interventions

Beyond supportive care, targeted therapies may be beneficial:

• Consider neostigmine (an anticholinesterase) for pharmacologic decompression, particularly in colonic pseudo-obstruction 6, 5
• Colonoscopic decompression may be effective for severe colonic dilatation with risk of perforation 4, 5
• Lactulose or polyethylene glycol solutions can be useful for small bowel ileus once electrolytes are corrected 5
• Early mobilization of the patient when clinically feasible helps restore bowel motility 2, 5

When to Escalate to Surgery

Immediate surgical consultation is mandatory if any of the following develop:

• Signs of peritonitis on physical examination 7, 2, 3
• CT evidence of bowel ischemia including abnormal bowel wall enhancement, pneumatosis, or mesenteric venous gas 7, 1
• Abdominal compartment syndrome with IAP >20-25 mmHg and organ dysfunction requiring decompressive laparotomy 4
• Free perforation with pneumoperitoneum 2
• Clinical deterioration despite 72 hours of appropriate conservative management 2, 3

Common Pitfalls to Avoid

• Do not delay CT imaging with prolonged plain film evaluation, as CT is far superior for distinguishing mechanical from functional obstruction 8
• Do not use water-soluble contrast in paralytic ileus—this is beneficial in adhesive mechanical small bowel obstruction but can worsen dehydration in ileus due to high osmolarity 2, 3
• Do not overlook medication-induced causes, particularly opioids and anticholinergics which are reversible 2, 6, 5
• Do not assume improvement means resolution—patients may feel better during resuscitation but still have underlying pathology requiring surgery 9
• Do not give prokinetics in complete obstruction as they can worsen the condition; reserve for partial obstruction only 3, 5