Can ileus cause leukocytosis?

Can Ileus Cause Leukocytosis?

Yes, ileus can cause leukocytosis, particularly when it progresses to a more severe condition with inflammation or ischemia of the bowel wall. Ileus is recognized as a potential cause of leukocytosis in several clinical guidelines and is listed as one of the diagnostic criteria for severe colitis in Clostridium difficile infection.

Pathophysiological Mechanisms

• Ileus can lead to intestinal dilatation, increased luminal pressure, and gut wall ischemia, triggering an inflammatory response that may result in leukocytosis 1
• The diffuse gastrointestinal dysmotility during ileus may promote intestinal bacterial overgrowth with potential bacterial translocation, further contributing to systemic inflammatory response 1
• Ileus is specifically listed as a sign of organ dysfunction in sepsis criteria, where it's described as "absent bowel sounds" and is associated with systemic inflammatory responses that include leukocytosis 2

Clinical Evidence from Guidelines

• In the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) guidelines, ileus is recognized as a sign of severe colitis, which is often accompanied by marked leukocytosis (leukocyte count >15 × 10^9/L) 2
• The Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA) guidelines for C. difficile infection specifically note that some patients, especially postoperative ones, may present with ileus and leukocytosis without diarrhea 2
• In fulminant C. difficile infection, ileus can be present alongside hypotension, shock, or megacolon, and is often associated with significant leukocytosis 2

Diagnostic Considerations

• When evaluating patients with ileus and leukocytosis, it's important to consider whether the ileus is:

  • Primary (paralytic/adynamic) or secondary to mechanical obstruction 1
  • Associated with infection (particularly C. difficile) 2
  • Causing increased intra-abdominal pressure with systemic consequences 1

• Laboratory findings that may accompany ileus with leukocytosis include:

  • Elevated C-reactive protein and procalcitonin 2
  • Increased serum lactate (indicating tissue hypoperfusion) 2
  • Electrolyte disturbances 2

Clinical Significance and Management Implications

• The presence of both ileus and leukocytosis should prompt consideration of severe disease requiring more aggressive management 2
• In C. difficile infection with ileus and leukocytosis, more aggressive treatment is recommended, including vancomycin 500 mg orally four times daily, potentially with rectal instillation if ileus is severe, plus intravenous metronidazole 2
• Leukocytosis >15,000 cells/mL in the setting of ileus is considered an unfavorable prognostic factor in C. difficile infection 2

Differential Diagnosis

When encountering ileus with leukocytosis, clinicians should consider several potential causes:

• Infectious causes: C. difficile, other bacterial infections 2
• Inflammatory conditions: Inflammatory bowel disease, eosinophilic enteritis 3
• Ischemic conditions: Mesenteric ischemia, strangulation 4
• Medication-induced: NSAIDs, opiates 3
• Postoperative ileus with inflammatory response 1

Conclusion

Ileus can indeed cause leukocytosis through several mechanisms, including bowel wall inflammation, ischemia, and bacterial translocation. The combination of ileus and leukocytosis often indicates a more severe clinical condition that requires prompt evaluation and management, particularly when associated with infections like C. difficile or conditions causing bowel ischemia.