What is the recommended treatment for Spontaneous Bacterial Peritonitis?

Treatment of Spontaneous Bacterial Peritonitis

For community-acquired SBP, start intravenous cefotaxime 2g every 6-8 hours or ceftriaxone 1-2g every 12-24 hours immediately upon diagnosis, combined with IV albumin (1.5 g/kg at diagnosis, then 1.0 g/kg on day 3) to reduce mortality from 29% to 10%. 1, 2, 3

Immediate Empirical Antibiotic Therapy

Community-Acquired SBP (First-Line Treatment)

• Third-generation cephalosporins are the gold standard for community-acquired SBP, with cefotaxime and ceftriaxone demonstrating the highest efficacy 1, 2
• Cefotaxime dosing: 2g IV every 6-8 hours achieves resolution rates of 69-98%, with studies showing that 4g/day is as effective as 8g/day 1, 2, 4, 5
• Ceftriaxone dosing: 1-2g IV every 12-24 hours achieves resolution rates of 73-100% and is equally effective as cefotaxime 1, 2, 6
• Treatment duration: 5-7 days is sufficient for most uncomplicated cases, as 5 days has been proven as effective as 10 days 1, 2, 3

Alternative Antibiotics for Community-Acquired SBP

• Amoxicillin-clavulanic acid (1g/0.2g IV every 8 hours) achieves 87% resolution rates, comparable to cefotaxime 1, 3
• Oral ciprofloxacin (500mg every 12 hours) can be used ONLY in clinically stable patients without sepsis, no recent antibiotic exposure, and not on quinolone prophylaxis 3
• Critical caveat: Avoid quinolones as first-line if the patient has received quinolone prophylaxis due to high resistance rates 2

Hospital-Acquired/Nosocomial SBP (Broader Coverage Required)

• Meropenem 1g IV every 8 hours PLUS daptomycin 6 mg/kg/day is significantly more effective than ceftazidime for nosocomial SBP (86.7% vs 25% resolution rate) 2, 7
• This broader regimen is critical for patients with recent hospitalization, ICU stay, or septic shock due to 35% multidrug-resistant organism prevalence 3, 7
• Do not use third-generation cephalosporins alone for nosocomial SBP—they provide inadequate coverage against resistant organisms 7, 8

Essential Adjunctive Therapy: IV Albumin

• Albumin is mandatory, not optional: Give 1.5 g/kg body weight within 6 hours of diagnosis, followed by 1.0 g/kg on day 3 2, 3, 9
• This reduces hepatorenal syndrome from 30% to 10% and mortality from 29% to 10% 2, 3, 9
• High-risk features requiring albumin: Serum creatinine ≥1 mg/dL, blood urea nitrogen ≥30 mg/dL, or total bilirubin ≥4 mg/dL 2

Monitoring Treatment Response

• Repeat paracentesis at 48 hours to assess neutrophil count decrease 1, 2, 3
• Treatment failure criteria: Ascitic neutrophil count fails to decrease to <25% of pre-treatment value, or clinical worsening 3, 7
• If treatment fails, suspect resistant organisms or secondary bacterial peritonitis and broaden coverage immediately 1, 3
• Adjust antibiotics based on culture results and narrow coverage when sensitivities are available 2, 3

Differentiating Secondary Bacterial Peritonitis

Secondary peritonitis has 50-80% mortality and requires surgical intervention, making differentiation critical 1:

• Suspect secondary peritonitis if: PMN count >1,000/mm³, multiple organisms on Gram stain/culture, ascitic protein ≥1 g/dL, ascitic LDH above normal serum upper limit, ascitic glucose ≤50 mg/dL, or PMN count fails to drop after 48 hours of antibiotics 1
• Perform abdominal CT if secondary peritonitis is suspected 1
• Elevated ascitic CEA (>5 ng/mL) or alkaline phosphatase (>240 U/L) suggests intestinal perforation 1

Long-Term Prophylaxis After SBP

• All patients surviving SBP require indefinite prophylaxis until liver transplantation or death, as 1-year recurrence risk is 70% without prophylaxis 2, 3, 9
• Norfloxacin 400mg daily is the most studied regimen, reducing recurrence from 68% to 20% 1, 2, 9
• Alternative regimens: Ciprofloxacin 500mg daily or co-trimoxazole (800mg sulfamethoxazole/160mg trimethoprim daily) 1, 2
• Important limitation: Increasing bacterial resistance is a major concern with long-term quinolone use 2, 3

Critical Pitfalls to Avoid

• Never delay antibiotics waiting for culture results—empirical therapy must start immediately upon diagnosis (PMN >250/mm³) 1, 3
• Avoid aminoglycosides (e.g., tobramycin) due to nephrotoxicity in cirrhotic patients 3, 4
• Do not use cephalosporins alone for nosocomial SBP—resistance rates are too high (only 57% coverage in some studies) 7, 8
• Recognize the shift in microbiology: Nearly half of isolates may be Gram-positive cocci, and standard cephalosporin coverage may be inadequate in certain populations 8
• Always give albumin with antibiotics in high-risk patients—this is the single most important intervention to prevent mortality 2, 3