Does paralytic ileus classically present with absent or decreased bowel sounds?

Paralytic Ileus Classically Presents with Absent Bowel Sounds

Yes, paralytic ileus classically presents with absent bowel sounds as a defining clinical feature. 1

Clinical Presentation of Paralytic Ileus

Paralytic ileus is characterized by cessation of bowel motility without a mechanical obstruction. The key clinical features include:

• Absent bowel sounds on auscultation (a hallmark physical examination finding) 1
• Abdominal distension (occurs in approximately 65% of cases) 2
• Abdominal pain and tenderness 2
• Absence of passage of flatus 2
• Absence of bowel movements 2
• Nausea and vomiting 2

Pathophysiology and Causes

Paralytic ileus results from impaired motor activity of the bowel and can be caused by various conditions:

• Post-surgical complication, especially following spinal surgery, traumatic injury, or lower extremity joint reconstruction 3
• Infections, including varicella zoster virus infection in rare cases 4
• Electrolyte imbalances 5
• Medications, particularly opioids 6
• Inflammatory conditions like peritonitis 6
• Strongyloidiasis hyperinfection syndrome in immunocompromised patients 1
• Sepsis and severe systemic inflammatory response 1

Diagnostic Approach

When evaluating a patient with suspected paralytic ileus, the following diagnostic approach is recommended:

• Physical examination focusing on:

  • Complete absence of bowel sounds (distinguishing feature) 2
  • Abdominal distension and tenderness 2
  • Signs of peritoneal irritation if advanced 6

• Imaging studies:

  • Plain abdominal radiographs showing gaseous distension of the colon and small bowel 4
  • CT scan with IV contrast to rule out mechanical obstruction (approximately 90% accuracy) 2

• Laboratory tests:

  • Complete blood count to assess for leukocytosis 6
  • Electrolyte panel to identify imbalances 6
  • Lactate levels to assess for intestinal ischemia 6

Management

The management of paralytic ileus should follow these principles:

• Conservative treatment:

  • Nasogastric tube placement for decompression 6
  • Correction of electrolyte abnormalities 6
  • Minimization of opioid use 3
  • Early patient mobilization 3

• Pharmacologic interventions:

  • Prokinetic agents for promoting bowel motility 6
  • Peripheral mu-opioid antagonists for opioid-induced dysfunction 6
  • Neostigmine administration in selected cases 7

• Antibiotics:

  • Indicated if bacterial infection or peritonitis is present 6
  • Duration of 4-7 days depending on severity and patient's immune status 1

Complications and Warning Signs

If left untreated, paralytic ileus can lead to serious complications:

• Bowel perforation 7
• Intestinal ischemia 5
• Malnutrition due to prolonged inability to tolerate oral intake 3
• Prolonged hospital stay and potential readmission 3
• Death in severe cases 3, 5

Warning signs of complications include:

• Fever, tachycardia, and confusion 2
• Intense pain unresponsive to analgesics 2
• Diffuse abdominal tenderness, guarding, or rebound tenderness 2
• Signs of shock including hypotension and oliguria 2

Clinical Pearls

• Absent bowel sounds are more specific for paralytic ileus than hyperactive bowel sounds, which can be seen in early mechanical obstruction 2
• Paralytic ileus is the single largest factor influencing length of hospital stay after bowel resection 5
• Early diagnosis and correct management is essential in reducing complications 5
• In elderly or neuropsychiatric patients, history may not be accurate, making physical examination findings like absent bowel sounds even more crucial 6