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Spontaneous bacterial peritonitis in adults: Clinical manifestations

Bruce A Runyon, MD
Section Editor
Keith D Lindor, MD
Deputy Editor
Kristen M Robson, MD, MBA, FACG


Spontaneous bacterial peritonitis (SBP) is defined as an ascitic fluid infection without an evident intra-abdominal surgically-treatable source; it primarily occurs in patients with advanced cirrhosis [1]. Typically, it is suspected when patients present with signs or symptoms of SBP. It may also be detected in patients who are asymptomatic who undergo paracentesis when admitted to the hospital for another reason. The diagnosis of SBP is established by a positive ascitic fluid bacterial culture, an elevated ascitic fluid absolute polymorphonuclear leukocyte (PMN) count (≥250 cells/mm3), and exclusion of secondary causes of bacterial peritonitis.

An elevated ascitic fluid absolute PMN count (≥250 cells/mm3) is adequate to make a presumptive diagnosis of SBP and to start empiric therapy. Too often, the paracentesis is performed after antibiotics are initiated and/or inadequate culture technique is used. In these situations, the cultures are regularly negative. (See "Spontaneous bacterial peritonitis in adults: Diagnosis".)

This topic will review the clinical manifestations of SBP. The pathogenesis of SBP, the diagnosis of SBP, differentiating SBP from a surgically-treatable cause of secondary bacterial peritonitis (eg, a perforated viscus), and the treatment and prophylaxis of SBP are discussed separately. (See "Pathogenesis of spontaneous bacterial peritonitis" and "Spontaneous bacterial peritonitis in adults: Diagnosis" and "Spontaneous bacterial peritonitis variants" and "Spontaneous bacterial peritonitis in adults: Treatment and prophylaxis".)


It is important to recognize spontaneous bacterial peritonitis early in the course of infection because there is frequently a very short window of opportunity during which to intervene to ensure a good outcome. If the opportunity is missed, shock ensues, followed rapidly by multisystem organ failure [2]. Survival is unlikely in patients who develop shock prior to initiation of empiric antibiotics. One report estimated that survival decreased by approximately 8 percent for each hour of delay in starting antibiotics in patients with septic shock [3]. Another study has shown that delayed paracentesis in patients with SBP leads to a 2.7 fold increase risk of death; each hour of delay in paracentesis is associated with a 3.3 percent increase in in-hospital mortality [4]. (See "Spontaneous bacterial peritonitis in adults: Treatment and prophylaxis", section on 'Indications for antibiotic therapy'.)


Patients with spontaneous bacterial peritonitis (SBP) typically have advanced cirrhosis [1]. The higher the Model for End-stage Liver Disease (MELD) score, the higher the risk of SBP [5]. Spontaneous infection of noncirrhotic ascites (eg, ascites due to malignancy or heart failure) is unusual enough to be the subject of case reports and small series. (See "Pathogenesis of spontaneous bacterial peritonitis".)

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Literature review current through: Nov 2017. | This topic last updated: Dec 15, 2016.
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  1. Such J, Runyon BA. Spontaneous bacterial peritonitis. Clin Infect Dis 1998; 27:669.
  2. Hoefs JC, Runyon BA. Spontaneous bacterial peritonitis. Dis Mon 1985; 31:1.
  3. Kumar A, Roberts D, Wood KE, et al. Duration of hypotension before initiation of effective antimicrobial therapy is the critical determinant of survival in human septic shock. Crit Care Med 2006; 34:1589.
  4. Kim JJ, Tsukamoto MM, Mathur AK, et al. Delayed paracentesis is associated with increased in-hospital mortality in patients with spontaneous bacterial peritonitis. Am J Gastroenterol 2014; 109:1436.
  5. Obstein KL, Campbell MS, Reddy KR, Yang YX. Association between model for end-stage liver disease and spontaneous bacterial peritonitis. Am J Gastroenterol 2007; 102:2732.
  6. Akriviadis EA, Runyon BA. Utility of an algorithm in differentiating spontaneous from secondary bacterial peritonitis. Gastroenterology 1990; 98:127.
  7. Runyon BA. Monomicrobial nonneutrocytic bacterascites: a variant of spontaneous bacterial peritonitis. Hepatology 1990; 12:710.
  8. McHutchison JG, Runyon BA. Spontaneous bacterial peritonitis. In: Gastrointestinal and Hepatic Infections, Surawicz CM, Owen RL (Eds), WB Saunders, Philadelphia 1994. p.455.
  9. EICHLER M, BESSMAN SP. A double-blind study of the effect of ammonium infusion on psychological functioning in cirrhotic patients. J Nerv Ment Dis 1962; 134:539.
  10. Conn HO. Trailmaking and number-connection tests in the assessment of mental state in portal systemic encephalopathy. Am J Dig Dis 1977; 22:541.
  11. Guarner C, Runyon BA, Young S, et al. Intestinal bacterial overgrowth and bacterial translocation in cirrhotic rats with ascites. J Hepatol 1997; 26:1372.