What is the recommended treatment for suspected fecal contamination of ascites?

Management of Suspected Fecal Contamination of Ascites

For suspected fecal contamination of ascites, immediate broad-spectrum antibiotic therapy with piperacillin/tazobactam or meropenem should be initiated, along with urgent surgical consultation for possible exploratory laparotomy. 1, 2

Diagnostic Approach

• Perform immediate diagnostic paracentesis to analyze ascitic fluid for signs of secondary bacterial peritonitis 3
• Send ascitic fluid for:
  • Cell count with differential (PMN count) 3
  • Culture with bedside inoculation into blood culture bottles 3
  • Total protein, LDH, glucose, and Gram stain 3
  • Consider amylase to help identify intestinal perforation 3

Distinguishing Secondary from Spontaneous Bacterial Peritonitis

Secondary bacterial peritonitis (from fecal contamination) should be suspected when:

• PMN count >1,000/mm³ 3
• Multiple organisms seen on Gram stain or culture 3
• Ascitic total protein ≥1 g/dL 3
• Ascitic LDH above the upper limit of normal for serum 3
• Ascitic glucose ≤50 mg/dL 3
• Elevated ascitic fluid CEA (>5 ng/mL) or alkaline phosphatase (>240 U/L) 3
• Inadequate response to antibiotic therapy after 48 hours 3

Treatment Algorithm

1. Initial Empiric Antibiotic Therapy:

   • Start broad-spectrum antibiotics immediately 3
   • Preferred regimens:
     • Piperacillin/tazobactam 4.5g IV every 6-8 hours 1, 2 OR
     • Meropenem 1g IV every 8 hours 2

2. Surgical Evaluation:

   • Urgent surgical consultation for suspected intestinal perforation 3, 1
   • Consider appropriate imaging (abdominal CT scan) to identify source of perforation 3

3. Follow-up Paracentesis:

   • Perform repeat diagnostic paracentesis at 48 hours to assess treatment response 3
   • Failure to show improvement in cell count and culture results suggests need for surgical intervention 3

4. Duration of Therapy:

   • Continue antibiotics for 7-10 days if responding to medical management 1, 2
   • Longer course may be needed based on clinical response and surgical findings 1

Important Considerations

• Secondary bacterial peritonitis from fecal contamination has a high mortality rate (50-80%) without appropriate surgical intervention 3
• Unnecessary laparotomy in cirrhotic patients also increases mortality, so accurate diagnosis is crucial 3
• Bacterial profiles in fecal contamination typically include multiple organisms, including anaerobes, which differs from spontaneous bacterial peritonitis 3, 1
• Albumin infusion (1.5 g/kg at diagnosis and 1 g/kg on day 3) should be considered to prevent renal failure, especially in patients with cirrhosis 4, 2

Pitfalls to Avoid

• Delaying surgical consultation when secondary bacterial peritonitis is suspected 3
• Treating as spontaneous bacterial peritonitis with inadequate antibiotic coverage 2
• Failing to perform repeat paracentesis at 48 hours to assess treatment response 3
• Not considering multidrug-resistant organisms in patients with previous antibiotic exposure 4, 2
• Continuing medical management alone when surgical intervention is indicated 3, 1