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

Treatment of Spontaneous Bacterial Peritonitis (SBP)

Start third-generation cephalosporins immediately upon diagnosis—specifically cefotaxime 2g IV every 8-12 hours or ceftriaxone 1-2g IV every 12-24 hours for 5-7 days—combined with IV albumin (1.5g/kg at diagnosis, then 1g/kg on day 3) to reduce mortality from 29% to 10%. 1

Immediate Empirical Antibiotic Therapy

Community-Acquired SBP (First-Line)

• Cefotaxime 2g IV every 8-12 hours is the gold standard, achieving 77-98% infection resolution rates 1, 2
• Ceftriaxone 1-2g IV every 12-24 hours is equally effective with 73-100% resolution rates 3
• Treatment duration is 5-7 days (5 days is as effective as 10 days) 1, 4
• Never delay antibiotics waiting for culture results—the ascitic fluid PMN count >250/mm³ alone is sufficient to start treatment 1, 2

Nosocomial or Healthcare-Associated SBP (Broader Coverage Required)

• Meropenem 1g IV every 8 hours plus daptomycin 6mg/kg/day is superior to ceftazidime (86.7% vs 25% efficacy) in nosocomial SBP where multidrug-resistant organisms (MDRO) prevalence reaches 35% 1, 5
• Use this regimen for patients in ICU, recent hospitalization, septic shock, or on quinolone prophylaxis 1

Alternative Antibiotic Options

For Uncomplicated Community-Acquired SBP

• Amoxicillin/clavulanic acid 1g/0.2g IV every 8 hours achieves 87% resolution, comparable to cefotaxime 1, 3
• Oral ofloxacin 400mg every 12 hours achieves 84% resolution in clinically stable patients without sepsis 1
• Oral ciprofloxacin 500mg every 12 hours for 5-7 days can be used only in stable patients meeting all criteria: community-acquired, no sepsis, no recent broad-spectrum antibiotics, not on quinolone prophylaxis 1

Critical Caveat

• Avoid quinolones in patients already on quinolone prophylaxis, in areas with high quinolone resistance, or in nosocomial SBP 2
• Avoid aminoglycosides (e.g., tobramycin) due to nephrotoxicity 1

Mandatory Adjunctive Albumin Therapy

IV albumin is non-negotiable and must be given alongside antibiotics:

• 1.5g/kg body weight within 6 hours of diagnosis 1, 2
• 1.0g/kg on day 3 1, 2
• This regimen reduces hepatorenal syndrome from 30% to 10% and mortality from 29% to 10% 1, 3, 6

Monitoring Treatment Response

48-Hour Paracentesis

• Repeat paracentesis at 48 hours to assess ascitic neutrophil count 1, 2
• Treatment success = PMN count decreases to <25% of pre-treatment value 1, 2
• Treatment failure = PMN fails to decrease by ≥25% or clinical worsening 1, 2

Management of Treatment Failure

• Suspect resistant bacteria or secondary peritonitis 2, 3
• Broaden coverage empirically to meropenem plus daptomycin 1
• Consider CT imaging to rule out secondary peritonitis requiring surgical intervention 2
• Adjust antibiotics based on culture sensitivities once available 2

Secondary Prophylaxis (Post-SBP)

All patients surviving an SBP episode require indefinite antibiotic prophylaxis:

• Norfloxacin 400mg PO daily reduces 1-year SBP recurrence from 68% to 20% 1, 3
• Ciprofloxacin 500mg PO daily is a reasonable alternative 1
• Continue prophylaxis until liver transplantation or death 3
• Tailor prophylaxis choice to local resistance patterns 1

Key Clinical Pitfalls to Avoid

• Never delay antibiotics for culture results—empirical therapy must start immediately upon PMN >250/mm³ 1, 2
• Culture-negative neutrocytic ascites (PMN >250/mm³ with negative culture) should be treated identically to culture-positive SBP 2
• Recognize the MDRO shift—nosocomial SBP now has 35% MDRO rate requiring broader initial coverage 1, 5
• Each hour of delay increases mortality by 3.3-10% in cirrhotic patients with septic shock 2, 7
• Hospital mortality remains ~20% despite infection resolution due to underlying liver disease and complications like hepatorenal syndrome 2, 6