Spontaneous Bacterial Peritonitis (SBP) Differential Diagnoses

Updated: Mar 23, 2021
  • Author: Thomas E Green, DO, MPH, CPE, MMM, FACEP, FACOEP; Chief Editor: Jeter (Jay) Pritchard Taylor, III, MD  more...
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Diagnostic Considerations

Diagnostic considerations include the following:

  • Secondary bacterial peritonitis

  • Perforated viscus

  • Pyelonephritis

Clinical features do not distinguish secondary bacterial peritonitis from spontaneous bacterial peritonitis. However, patients with secondary bacterial peritonitis have a surgically treatable source of infection (eg, perforated duodenal ulcer, perinephric abscess).

In secondary bacterial peritonitis from free perforation of a viscus, the peritoneal fluid analysis characteristically shows an extremely elevated polymorphonuclear neutrophil count, multiple organisms (often including fungi and Enterococcus) on Gram stain and culture, and at least two of the following criteria [4] :

  • Total protein greater than 1 g/dL

  • Lactate dehydrogenase above the upper limit of normal for serum

  • Glucose less than 50 mg/dL

Differential Diagnoses