Spontaneous Bacterial Peritonitis
Definition: Acute infection of the ascitic fluid in a patient with liver disease without another source of infection Epidemiology: (Runyon 1988, Runyon 1988, Borzio 2001) Incidence 10-25% risk of at least one episode per year 20% risk in those with ascites admitted to the hospital Historically, mortality ~ 50% Pathophysiology: Not completely understood Increased portal systemic hypertension Causes mucosal edema of the bowel wall
Increases transmural migration of enteric organisms into the ascitic fluid Impaired phagocytic function in the liver Impaired immunologic activity in ascitic
Presentation: Classic triad: fever, abdominal pain and increasing ascites. Presence of all three components uncommon
Symptoms
Fever or chills
Abdominal pain
Abdominal swelling
Fatigue
Malaise
Signs
Abdominal tenderness variable
Typically diffuse
Can be mild without peritoneal signs
Can be severe with rebound and/or guarding
Abdominal distension
Altered mental status (from hepatic encephalopathy)
Diagnostics: Obtaining an ascitic fluid sample is critical in making the diagnosis Serum blood tests (i.e. WBC, CRP, ESR) are not helpful in making this diagnosis Due to variable presentations and considerable mortality associated with SBP, consideration should be made to perform paracentesis on ALL patients with ascitic fluid who are being admitted (Gaetano 2016) Diagnostic paracentesis (EM: RAP HD)
Ascitic fluid assays Cell count Look for WBC > 250-500 cells/mm3 or neutrophil count > 250 cells/mm3 Peritoneal dialysis patients: neutrophil count > 100 cells/mm pH < 7.34 more common in SBP (Wong 2008) Ascitic fluid gram stain (rarely positive) and culture If patient has fever (temp > 100oF) or abdominal pain/tenderness, empiric antibiotics should be given even if neutrophil count < 250 cells/mm3
Management:
Antibiotics Most common bacterial causes: E. Coli, S. Pneumoniae, Enterococci 3rd Generation Cephalosporin covers vast majority of cases Ceftriaxone 25 mg/kg up to 2 gm daily Cefotaxime 25 mg/kg up to 1 gm Q8 Alternate antibiotic choices Ciprofloxacin 400mg IV BID Levofloxacin 750mg IV daily Piperacillin/Tazobactam 4.5g IV TID Ertapenem 1g IV qD Imipenem/Cilastatin 500mg IV QID
Albumin Infusion (Runyon 2012) Recommended by American Association for the Study of Liver Disease (AASLD) in specific subgroups with SBP Presence of any of the following should prompt albumin administration Serum creatinine > 1 mg/dL Blood urea nitrogen (BUN) > 30 mg/dL Total Bilirubin > 4 mg/dL Impact of albumin infusion (Sort 1999) 25% reduction in renal failure 20% reducing n mortality Dose 1.5 grams/kg within 6 hours 1.0 grams/kg on day 3 of treatment Patients with a single episode of SBP should be considered for antibiotic prophylaxis (with norfloxacin, ciprofloxacin or TMP/SMX) (Runyon 2012)
Take Home Points:
SBP is a difficult diagnosis to make because presentations are variable. Consider a diagnostic paracentesis in all patients presenting to the ED with ascites from cirrhosis
An ascites PMN count > 250 cells/mm3 is diagnostic of SBP but treatment should be considered in any patient with ascites and abdominal pain or fever
Treatment of SBP is with a 3rd generation cephalosporin with the addition of albumin infusion in any patient meeting AASLD criteria (Cr > 1.0 mg/dL, BUN > 30 mg/dL or Total bilirubin > 4 mg/dL)
Topic Checkout: Oyama LC: Disorders of the liver and biliary tract, in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 8. St. Louis, Mosby, Inc., 2010, (Ch) 90: p 1186-1205. EMRAP: C3 Live Paracentesis Video LITFL: Spontaneous Bacterial Peritonitis SinaiEM: SBP Pearls REBEL EM: Should You Give Albumin in Spontaneous Bacterial Peritonitis (SBP)?
References: Runyon BA et al. Ascitic fluid analysis in malignancy‐related ascites. Hepatology 1988; 8(5):1104-1109. PMID: 3417231
Runyon BA. Spontaneous bacterial peritonitis: An explosion of information. Hepatology 1988; 8: 171–175. PMID: 3338704
Borzio M et al. Bacterial infection in patients with advanced cirrhosis: a multicentre prospective study. Dig Liver Dis 2001; 33(1): 41-48. PMID: 11303974
Gaetano et al. The benefit of paracentesis on hospitalized adults with cirrhosis and ascites. Journal of Gastroenterology and Hepatology 2016. PMID: 26642977 Wong CL et al. Does this patient have bacterial peritonitis or portal hypertension? How do I perform a paracentesis and analyze the results?
JAMA 2008; 299(10):1166-78. PMID: 18334692
Runyon BA. Management of Adult Patients with Ascites Due to Cirrhosis: Update 2012. AASLD Practice Guideline. Link
Sort P et al. Intravenous albumin in patients with cirrhosis and spontaneous bacterial peritonitis. NEJM 1999; 341: 1773-4. PMID: 10432325
