Treatment of Spontaneous Bacterial Peritonitis in Cirrhotic Patients with Ascites
Immediately initiate empirical antibiotic therapy with a third-generation cephalosporin (cefotaxime 2g IV every 6-8 hours or ceftriaxone 1-2g IV every 12-24 hours) for 5-7 days, combined with intravenous albumin (1.5 g/kg at diagnosis and 1.0 g/kg on day 3) to reduce mortality and prevent hepatorenal syndrome. 1, 2
Immediate Diagnostic and Treatment Steps
Start Antibiotics Without Delay
- Begin empirical antibiotics immediately upon diagnosis (ascitic fluid PMN >250/mm³), without waiting for culture results 1, 2
- Each hour of delay in antibiotic initiation increases mortality by 10% in cirrhotic patients with septic shock 1
- Obtain ascitic fluid culture by bedside inoculation of at least 10 mL into blood culture bottles before starting antibiotics, and simultaneously obtain blood cultures 1, 2
First-Line Antibiotic Regimen
Community-Acquired SBP
- Cefotaxime 2g IV every 6-8 hours for 5 days is the most extensively studied regimen with 77-98% resolution rates 1, 2
- Ceftriaxone 1-2g IV every 12-24 hours for 5 days is equally effective 1, 2
- A 5-day course is as effective as 10 days of treatment 2
Alternative Antibiotics for Specific Situations
- Oral ofloxacin 400mg twice daily can be used in uncomplicated SBP (without renal failure, hepatic encephalopathy, gastrointestinal bleeding, ileus, or shock) 1, 2
- Amoxicillin-clavulanic acid (1g/0.2g IV every 8 hours, followed by 0.5g/0.125g PO every 8 hours) shows similar resolution rates to cefotaxime 1
- Avoid quinolones in patients already taking them for prophylaxis, in areas with high quinolone resistance, or in nosocomial SBP 1
Nosocomial or Healthcare-Associated SBP
- Meropenem 1g IV every 8 hours plus daptomycin 6mg/kg/day is significantly more effective than ceftazidime (86.7% vs 25% resolution) for nosocomial SBP due to high prevalence of multidrug-resistant organisms 3, 4
- Consider broader spectrum coverage with piperacillin-tazobactam or carbapenems for hospital-acquired infections 3, 5
Essential Albumin Therapy
Albumin administration is mandatory, not optional, and provides mortality benefit independent of antibiotics. 2, 3
- Administer IV albumin 1.5 g/kg body weight within 6 hours of diagnosis, followed by 1.0 g/kg on day 3 1, 2
- This regimen reduces mortality from 29% to 10% and decreases type 1 hepatorenal syndrome from 30% to 10% 1, 2
- Albumin is particularly effective in patients with baseline serum bilirubin ≥4 mg/dL or serum creatinine ≥1 mg/dL 1
- The benefit is less clear in patients with bilirubin <4 mg/dL and creatinine <1 mg/dL, where hepatorenal syndrome risk is already low 1
Monitoring Treatment Response
Repeat Paracentesis at 48 Hours
- Perform a second paracentesis after 48 hours of treatment to assess efficacy 1, 2
- Treatment success is defined as a decrease in ascitic PMN count to <25% of pre-treatment value 1, 2, 3
- Clinical improvement should accompany the laboratory response 2
Treatment Failure Recognition
- Suspect treatment failure if PMN count fails to decrease by at least 25%, or if clinical signs and symptoms worsen 1, 2
- Treatment failure is usually due to resistant bacteria or secondary bacterial peritonitis 1
- Change antibiotics according to culture sensitivities or escalate empirically to broader-spectrum agents 1, 3
Critical Pitfalls to Avoid
Rule Out Secondary Bacterial Peritonitis
- Never assume SBP in the presence of surgical drains or recent abdominal procedures—always rule out secondary peritonitis first 3
- Suspect secondary peritonitis if: PMN >1,000/mm³, multiple organisms on culture, ascitic protein ≥1 g/dL, ascitic LDH above normal serum LDH, ascitic glucose ≤50 mg/dL, or PMN count fails to decrease after 48 hours of antibiotics 1, 6
- Obtain abdominal CT imaging if secondary peritonitis is suspected 1, 3, 6
Antibiotic Selection Errors
- Never use aminoglycosides due to nephrotoxicity in cirrhotic patients 3
- Do not use quinolones in patients on quinolone prophylaxis or in nosocomial SBP 1
- For patients developing SBP while on norfloxacin prophylaxis, use cefotaxime or amoxicillin-clavulanic acid 1, 2
Albumin Administration
- Never forget albumin administration—it significantly reduces mortality and is not optional 3
- Albumin improves circulatory function while equivalent doses of hydroxyethyl starch do not 1
Post-Treatment Management
Secondary Prophylaxis
- All patients surviving SBP require indefinite secondary prophylaxis with norfloxacin 400mg PO daily (or ciprofloxacin 500mg daily) until ascites resolves or liver transplantation occurs 3
- Liver transplant evaluation should be undertaken for all patients who develop SBP, barring contraindications 5