Treatment of Spontaneous Bacterial Peritonitis in Cirrhotic Adults
Initiate intravenous cefotaxime 2 g every 8 hours immediately, and add albumin infusion (1.5 g/kg within 6 hours, then 1.0 g/kg on day 3) to reduce mortality from 29% to 10%. 1, 2
Immediate Antibiotic Therapy
The diagnosis is confirmed: PMN >250 cells/mm³ with fever represents spontaneous bacterial peritonitis (SBP) requiring urgent empiric treatment. 1
First-line antibiotic options:
- Cefotaxime 2 g IV every 8 hours (most studied, preferred) 1
- Ceftriaxone 1-2 g IV every 12-24 hours (equally effective alternative) 1, 3
- Oral ofloxacin 400 mg twice daily (only if no vomiting, shock, grade ≥II encephalopathy, or creatinine >3 mg/dL) 1, 2
Treatment duration is 5 days if clinical response is adequate and PMN count drops below 250 cells/mm³. 1, 4
Critical Addition: Albumin Infusion
Albumin administration dramatically improves survival and must be given concurrently with antibiotics: 1, 2
- 1.5 g/kg body weight within 6 hours of diagnosis
- 1.0 g/kg on day 3
This reduces mortality from 29% to 10% (P=0.01) and prevents renal failure (10% vs 33%, P=0.002). 1 Albumin is particularly essential when creatinine ≥1 mg/dL, BUN ≥30 mg/dL, or bilirubin ≥4 mg/dL. 1
Distinguishing Secondary Peritonitis
Before committing to SBP treatment alone, order additional ascitic fluid tests to exclude surgical peritonitis: 1
- Total protein
- LDH
- Glucose
- Gram stain
Suspect secondary peritonitis requiring surgery if: 1
- PMN count >1,000 cells/mm³
- Multiple organisms on Gram stain/culture
- At least 2 of 3 criteria: total protein ≥1 g/dL, LDH > upper limit of normal for serum, glucose <50 mg/dL
- Ascitic CEA ≥5 ng/mL or alkaline phosphatase ≥240 U/L (indicates gut perforation)
- PMN count rises despite 48 hours of appropriate antibiotics
If secondary peritonitis is confirmed, add anaerobic coverage and obtain urgent surgical consultation. 1
Monitoring Response
Repeat paracentesis is NOT routinely necessary if the patient has typical SBP (advanced cirrhosis, single organism expected, dramatic clinical improvement). 1
Perform repeat paracentesis at 48 hours only if: 1
- Atypical presentation
- No clinical improvement
- Multiple organisms isolated
- Concern for secondary peritonitis
Treatment failure (absence of clinical improvement or <25% decrease in PMN count by 72 hours) occurs in approximately 19-38% of cases. 5, 6
Management of Treatment Failure
If cefotaxime fails after 48-72 hours: 6
- Switch to meropenem (100% response rate in cefotaxime-resistant cases) 6
- Alternative: levofloxacin (75% response rate) 6
- Cefoperazone-sulbactam may be superior to third-generation cephalosporins in some settings (93.3% vs 50% sensitivity) 5
Resistance patterns are evolving, with gram-positive organisms (enterococci, Staphylococcus aureus) and ESBL-producing organisms increasingly common, particularly in patients with prior quinolone prophylaxis. 1, 5, 6
Common Pitfalls
Do not delay treatment waiting for culture results - delaying antibiotics until cultures are positive may result in death from overwhelming infection. 1 The PMN count is rapidly available and sufficient to guide empiric therapy. 1
Do not omit albumin - this is not just volume expansion; albumin specifically reduces mortality and renal failure beyond antibiotic effects alone. 1, 2
Do not assume all elevated PMN counts are SBP - hemorrhagic ascites, peritoneal carcinomatosis, pancreatitis, and tuberculosis can elevate PMN counts without infection. 1 Clinical context matters.
Patients on quinolone prophylaxis require alternative antibiotics - they likely harbor quinolone-resistant organisms and should receive cefotaxime or broader coverage from the start. 1