Diagnosis and Management of Spontaneous Bacterial Peritonitis

Diagnostic Criteria

The American Association for the Study of Liver Diseases recommends a diagnostic threshold for spontaneous bacterial peritonitis of ≥ 250 polymorphonuclear neutrophils (PMN)/mm³ (0.25 × 10^9/L) in ascitic fluid 1, 2, 3
A patient with a nucleated cell count of 0.082 × 10^9/L in ascitic fluid is below the diagnostic threshold and does not require empirical antibiotic treatment 1, 3

The American Association for the Study of Liver Diseases suggests that no antibiotic treatment is indicated in the absence of clinical signs of infection and with a nucleated cell count < 250 cells/mm³ 1, 4
If a patient develops signs or symptoms of infection (fever, abdominal pain, unexplained deterioration), a new diagnostic paracentesis should be performed immediately 4, 5
In cases where symptoms suggestive of infection appear despite a normal PMN count, empirical antibiotic treatment may be considered while awaiting culture results 3, 5

Monomicrobial non-neutrocytic bacterascites: some patients may have a positive culture despite a PMN count < 250 cells/mm³, with 62% of these patients spontaneously clearing the colonization without antibiotic treatment 2, 5
Alcoholic hepatitis: these patients may present with symptoms mimicking spontaneous bacterial peritonitis (fever, leukocytosis, abdominal pain), and diagnostic paracentesis is essential to differentiate between true infection and inflammation related to alcoholic hepatitis 5

First-line treatment: cefotaxime 2g every 8 hours intravenously 3, 4
Alternative: oral ofloxacin 400mg twice daily in patients without vomiting, shock, or grade II or higher hepatic encephalopathy, and with a serum creatinine < 3 mg/dL 4
The addition of albumin (1.5 g/kg on day 1 and 1 g/kg on day 3) to antibiotic treatment significantly reduces mortality from 29% to 10% 1, 4