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Spontaneous bacterial peritonitis

Last reviewed: 30 Oct 2023
Last updated: 05 Nov 2021



History and exam

Key diagnostic factors

  • abdominal pain or tenderness
  • signs of ascites
  • fever
  • nausea/vomiting
  • diarrhea
  • altered mental status
  • gastrointestinal bleed
More key diagnostic factors

Other diagnostic factors

  • hypothermia
  • hypotension
  • tachycardia
Other diagnostic factors

Risk factors

  • decompensated hepatic state (usually cirrhosis)
  • low ascitic protein/complement
  • gastrointestinal bleeding
  • endoscopic sclerotherapy for esophageal varices
  • ascites due to malignancy, renal insufficiency, or congestive heart failure
  • extraintestinal infection
  • invasive procedures
More risk factors

Diagnostic investigations

1st investigations to order

  • CBC
  • serum creatinine
  • ascitic fluid appearance
  • ascitic fluid absolute neutrophil count (ANC)
  • ascitic fluid culture
  • blood cultures
  • LFT
  • prothrombin time/INR
More 1st investigations to order

Investigations to consider

  • highly-sensitive leukocyte esterase reagent strip testing of ascitic fluid (Periscreen)
  • bedside (standard urine) leukocyte esterase reagent strip testing of ascitic fluid
  • ascitic fluid protein, glucose, lactate dehydrogenase (LDH)
  • serum-ascites albumin gradient (SAAG)
  • ascitic fluid pH and arterial blood pH
  • ascitic fluid carcinoembryonic antigen (CEA)
  • ascitic fluid alkaline phosphatase
  • CT scan abdomen
More investigations to consider

Emerging tests

  • ascitic fluid lactoferrin
  • ascitic fluid PCR for bacterial DNA
  • serum procalcitonin

Treatment algorithm


community-acquired infection

nosocomial infection, septic shock, high risk for resistant species



Brian Chinnock, MD

Associate Professor of Emergency Medicine

UCSF Fresno Medical Education Program




BC is an author of references cited in this topic.

Peer reviewers

Andrea De Gottardi, MD, PhD

Visiting Hepatologist

Hepatic Hemodynamic Laboratory

Liver Unit

Hospital Clinic




ADG declares that he has no competing interests.

Kia Saeian, MD

Associate Professor of Medicine

Program Director

Gastroenterology Fellowship Program

Medical College of Wisconsin




KS declares that he has no competing interests.

Joseph K. Lim, MD

Assistant Professor of Medicine


Yale Viral Hepatitis Program

Section of Digestive Diseases

Yale School of Medicine

New Haven



JKL declares that he has no competing interests.

  • Spontaneous bacterial peritonitis images
  • Differentials

    • Secondary peritonitis
    • Tuberculous peritonitis
    • Intraperitoneal hemorrhage into ascitic fluid
    More Differentials
  • Guidelines

    • Diagnosis, evaluation, and management of ascites, spontaneous bacterial peritonitis and hepatorenal syndrome
    • EASL clinical practice guidelines for the management of patients with decompensated cirrhosis
    More Guidelines
  • Patient leaflets

    Ascitic tap and ascitic drain procedures

    More Patient leaflets
  • Videos

    Ascitic drainage: animated demonstration

    Peripheral venous cannulation: animated demonstration

    More videos
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