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

Treatment of Spontaneous Bacterial Peritonitis (SBP)

Empirical antibiotic therapy must be initiated immediately after the diagnosis of SBP, with third-generation cephalosporins being the first-line treatment. 1

Diagnosis of SBP

• SBP is diagnosed when the ascitic fluid neutrophil count is >250/mm³, regardless of culture results 1
• Diagnostic paracentesis should be performed in all cirrhotic patients with ascites at hospital admission, and in those with gastrointestinal bleeding, shock, fever, signs of systemic inflammation, worsening liver/renal function, or hepatic encephalopathy 1
• Blood cultures should be obtained before starting antibiotics to guide therapy 1
• Ascitic fluid should be cultured in blood culture bottles to improve yield, though culture positivity is not required for diagnosis 1, 2

First-Line Antibiotic Treatment

• Third-generation cephalosporins are the first-line empirical treatment for SBP 1
• Cefotaxime at 4 g/day (typically 2 g every 12 hours) is as effective as higher doses and achieves high ascitic fluid concentrations 1
• A 5-day course is as effective as a 10-day course for uncomplicated SBP 1
• Infection resolution rates with cefotaxime range from 77-98% 1

Alternative Antibiotic Options

• Amoxicillin/clavulanic acid (initially IV then oral) has similar efficacy to cefotaxime at lower cost, but has been studied in only one small trial and carries risk of drug-induced liver injury 1
• Ciprofloxacin (IV or switch therapy) is effective but more costly than cefotaxime 1
• Oral ofloxacin can be used in uncomplicated SBP without renal failure, hepatic encephalopathy, GI bleeding, ileus, or shock 1
• Quinolones should be avoided in patients already taking them for prophylaxis or in areas with high quinolone resistance 1, 3

Adjunctive Albumin Therapy

• Intravenous albumin (1.5 g/kg at diagnosis followed by 1 g/kg on day 3) significantly reduces the incidence of hepatorenal syndrome (from 30% to 10%) and mortality (from 29% to 10%) 1, 4
• Albumin is particularly beneficial in patients with baseline serum bilirubin ≥68 μmol/L (4 mg/dl) or serum creatinine ≥88 μmol/L (1 mg/dl) 1, 2

Monitoring Treatment Response

• Treatment success should be confirmed by demonstrating a decrease in ascitic neutrophil count to <250/mm³ and sterile cultures (if initially positive) 1, 3
• A second paracentesis after 48 hours of treatment helps guide antibiotic efficacy 1, 4
• If the neutrophil count fails to decrease by at least 25% after 2 days of treatment, consider treatment failure 1

Special Considerations

• For healthcare-associated or nosocomial SBP, broader-spectrum antibiotics may be needed due to increasing prevalence of multi-drug resistant organisms 1, 2
• Secondary bacterial peritonitis (due to perforation or inflammation of intra-abdominal organs) should be suspected with multiple organisms on culture, very high neutrophil count, high ascitic protein, or inadequate response to therapy 1
• Patients with suspected secondary bacterial peritonitis require prompt CT scanning and surgical evaluation 1

Prevention of Recurrence

• After a first episode of SBP, long-term antibiotic prophylaxis should be initiated as recurrence risk is approximately 70% within one year 1, 5
• Patients who develop SBP should be evaluated for liver transplantation 6, 3

Common Pitfalls

• Delaying antibiotic therapy while waiting for culture results increases mortality 1, 2
• Using nephrotoxic antibiotics (e.g., aminoglycosides) as empirical therapy should be avoided 1
• Failing to administer albumin in high-risk patients significantly increases mortality 1, 4
• Not considering multi-drug resistant organisms in healthcare-associated or nosocomial SBP 1, 3