What is the recommended treatment and duration for Spontaneous Bacterial Peritonitis (SBP)?

Treatment and Duration for Spontaneous Bacterial Peritonitis (SBP)

Third-generation cephalosporins should be started immediately upon diagnosis of SBP, with a standard treatment duration of 5-10 days, and intravenous albumin should be added for patients with high risk of renal failure. 1, 2

Diagnosis Criteria

• SBP diagnosis is confirmed when ascitic fluid polymorphonuclear leukocyte (PMN) count is >250/mm³, regardless of culture results 1, 2
• Empirical antibiotics should be started even with PMN <250/mm³ if infection symptoms are present (fever >37.8°C, abdominal pain/tenderness) 1, 2

First-Line Antibiotic Treatment

• Cefotaxime 2g IV every 6-8 hours OR Ceftriaxone 1-2g IV every 12-24 hours 1, 2
• These third-generation cephalosporins are effective against the most common causative organisms (E. coli, Klebsiella pneumoniae, and Streptococcus)
• Treatment duration: 5-10 days 1, 2
  • A 5-day treatment regimen has shown similar efficacy to 10-day treatment 1, 3

Alternative Antibiotic Options

• Amoxicillin-clavulanic acid: 1g/0.2g IV every 8 hours, followed by 500mg/125mg PO every 8 hours 1, 2
• Oral ofloxacin (400mg every 12 hours) - only for uncomplicated SBP without renal failure, hepatic encephalopathy, GI bleeding, ileus, or shock 1, 2

Important Adjunctive Therapy

• Intravenous albumin (1.5g/kg at diagnosis, followed by 1g/kg on day 3) significantly reduces:
  • Incidence of type 1 hepatorenal syndrome (from 30% to 10%)
  • Mortality (from 29% to 10%) 1, 2
• Particularly beneficial for high-risk patients with:
  • Baseline serum bilirubin ≥4 mg/dl OR
  • Serum creatinine ≥1 mg/dl 1, 2

Monitoring Response to Treatment

• Perform a second paracentesis after 48 hours of treatment 1, 2
• Treatment success: decrease in ascitic neutrophil count to <250/mm³ and sterile cultures
• Treatment failure indicators:
  • No marked reduction in ascitic fluid neutrophil count
  • Worsening of clinical signs and symptoms
  • Failure of ascitic PMN count to decrease by at least 25% of pre-treatment value 2

Special Considerations

1. Nosocomial SBP:

   • Higher risk of antibiotic-resistant organisms
   • Consider broader-spectrum antibiotics like meropenem plus daptomycin 2, 4
   • Recent research shows carbapenems may be superior to third-generation cephalosporins in critically ill patients (CLIF-SOFA scores ≥7) 5

2. Patients on quinolone prophylaxis:

   • Avoid quinolones for empiric therapy
   • Use cefotaxime or amoxicillin-clavulanic acid 2

3. Secondary bacterial peritonitis should be suspected if:

   • PMN count >1,000/mm³
   • Multiple organisms on culture
   • Ascitic total protein ≥1g/dL
   • Ascitic glucose ≤50mg/dL
   • No improvement after 48 hours of antibiotics 1, 2

Common Pitfalls to Avoid

1. Delaying antibiotic treatment while waiting for culture results
2. Failing to add albumin therapy in high-risk patients
3. Not performing follow-up paracentesis to confirm treatment response
4. Using quinolones empirically in patients already on quinolone prophylaxis
5. Missing secondary bacterial peritonitis which requires surgical intervention

The high efficacy of third-generation cephalosporins in SBP can be maintained with optimized dosing regimens, with ceftriaxone 2g once daily showing 95% cure rates in a 5-day course 6, making it a convenient option with excellent outcomes.