Snapshot A 46-year-old male presents with abdominal pain and confusion. His medical history is significant for advanced cirrhosis secondary to chronic alcohol abuse. Temperature is 100.2°F (37.8°C), blood pressure is 125/80 mmHg, pulse is 106/min, and respirations are 22/min. On physical exam, there is abdominal distension, diffuse abdominal tenderness to palpation, flank dullness, and a positive fluid wave. Introduction Infection of ascitic fluid not explained by a surgically-treatable intraabdominal source e.g., infection, or malignancy may be due to bacterial translocation from the intestine into the ascitic fluid microbiology commonly Escherichia coli, Klebsiella, Streptococcus Epidemiology most commonly occurs in patients with advanced cirrhosis can result from any disease process that leads to ascites e.g., right heart failure can occur in children with nephrotic syndrome Presentation Symptoms altered mental status abdominal pain diarrhea Physical exam fever diffuse abdominal tenderness a sign of peritonitis flank dullness shifting dullness fluid wave Evaluation Diagnostic paracentesis serum ascities albumin gradient (SAAG) > 1.1 SBP most commonly occurs in patients with portal hypertension ≥ 250 cells/mm3 protein < 1 g/dL ↓ concentration of opsonin, increasing the risk of SBP glucose > 50 mg/dL Gram stain fluid culture Differential Secondary peritonitis Treatment Antibiotics must be given AFTER paracentesis 3rd generation cephalosporin e.g., cefotaxime, ceftriaxone Discontinue nonselective β-blockers Prognosis, Prevention, Complications Prognosis 90% of cases resolve with proper antibiotic treatment Prevention antibiotic prophylaxis in patients with risk factors for SBP agent: trimethoprim-sulfamethoxazole, or fluoroquinolone Complications renale failure sepsis