Spontaneous Bacterial Peritonitis (SBP)

Overview

SBP is a serious infection of ascitic fluid, most commonly seen in children with chronic liver disease. It occurs without an evident intra-abdominal source and requires prompt diagnosis and treatment.

Risk Factors

• Chronic liver disease (especially cirrhosis)
• Nephrotic syndrome
• Protein-losing enteropathy
• Congestive heart failure
• Acute liver failure or viral hepatitis

Pathophysiology

Children with ascites are immunocompromised due to low complement levels, impaired neutrophil function, and increased intestinal permeability, which facilitates bacterial translocation.

Diagnosis

• Clinical signs: fever, abdominal pain, vomiting, encephalopathy, renal dysfunction (may be subtle or may have worsening fatigue)
  
• Paracentesis: PMN count ≥250 cells/mm³ is diagnostic
• Ascitic fluid analysis: low protein, low glucose, positive culture (may be negative in 50%)

Common Pathogens

• Gram-negative: E. coli, Klebsiella pneumoniae
• Gram-positive: Streptococcus pneumoniae, Enterococcus, Staphylococcus aureus
• Anaerobes are rare

Treatment

• Empiric antibiotics: Cefotaxime or ceftriaxone
• Albumin therapy: 1.5 g/kg at diagnosis, 1 g/kg at 48 hours
• Supportive care: fluid restriction, nutritional support, monitor renal function

Prophylaxis

• Secondary: Rifaximin, Bactrim, ciprofloxacin
• Primary: For high-risk patients (e.g., ascitic protein <1.5 g/dL)

Summary Table