SBP = an ascitic fluid infection without an evident intra-abdominal surgically treatable source. SBP usually occurs in patients with cirrhosis and ascites
Dx is made with a positive ascitic fluid bacterial culture and an ascitic fluid absolute polymorphonuclear leukocyte count ≥250 cells/mm3.
-Perform abd paracentesis and obtain ascitic fluid (AF)
-Order AF cell count and differential, AF total protein, and serum-ascites albumin gradient (SAAG).
-Order AF Cx, BCx, UCx, Sputum Cx, prior to initiation of antibiotics.
-Start empiric abx therapy ASAP. E.g. Cefotaxime 2g q8h IV
-Give IV albumin 1.5g/kg at diagnosis followed by 1g/kg on day 3.
-Common causative agents: Gut bacteria such as Escherichia coli and Klebsiella. However, streptococcal and staphylococcal infections can also occur.
-D/C nonselective beta blockers
INDICATIONS FOR ANTIBIOTIC TREATMENT
Start empiric therapy for SBP in a patient with ascites who has one or more of the following findings:
- Temperature greater than 37.8°C (100°F)
- Abdominal pain and/or tenderness
- A change in mental status (AMS)
- Ascitic fluid polymorphonuclear leukocyte (PMN) count ≥250 cells/mm3
Be concerned in patients with diarrhea, paraclytic ileus, hypotension, and hypothermia.
If a patient doesn’t have any of first three signs above, it’s best to wait for the ascitic fluid results to come back and start abx if PMNs are equal to or greater than 250.
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“Primary prophylaxis of SBP has been associated with a decreased risk of bacterial infection and decreased mortality in patients considered to be at high risk of SBP, which includes patients with a history of variceal bleeding or ascites fluid protein levels below 1.0 g/dL.Primary prophylaxis is achieved with long-term use of quinolones, such as 400 mg of norfloxacin daily or, as an alternative, 1 double-strength tablet of trimethoprim-sulfamethoxazole daily” Can FP 2016
AF= Ascitic fluid
Guidelines for Management of Adults with Ascites due to Cirrhosis: http://www.aasld.org/sites/default/files/guideline_documents/adultascitesenhanced.pdf
“A WBC count >250/mL in ascitic fluid from paracentesis indicates a high risk for spontaneous bacterial peritonitis (SBP) and is an indication for immediate empiric antibiotic therapy to prevent SBP, which is associated with a high mortality rate in patients with cirrhosis and ascites (SOR A). Bacterial cultures to identify the etiology of SBP may be helpful in guiding antibiotic choices (SOR C). However, cultures are negative in a significant percentage of patients with SBP, and waiting on culture results, which may take 48–72 hours, would delay empiric antibiotic treatment in high-risk patients.
The serum-ascites albumin gradient (SAAG) helps determine whether peritoneal fluid is a transudate or exudate. Theoretically it might also be helpful in the diagnosis of SBP, as the ascitic fluid would normally be expected to have a relatively high protein level. This is not the case in many patients with confirmed SBP, however, so the SAAG is not a reliable aid for making the diagnosis.
A single study of patients with alcoholic cirrhosis and ascites, in which 25% of patients were found to have SBP based on the WBC count and bacterial cultures, tested whether leukocyte esterase reagent test strips and nitrite test strips were helpful in making the diagnosis of SBP. The researchers found that the leukocyte esterase test strips had a sensitivity of 93%, a specificity and positive predictive value of 100%, and a negative predictive value of 98%. The nitrite test strips, however, demonstrated a sensitivity of only 13%, a specificity of 93%, a positive predictive value of 40%, and a negative predictive value of 77%. The conclusion was that leukocyte esterase test strips, with apparently reliable results within minutes of paracentesis, might be helpful in the rapid diagnosis of SBP (SOR B), whereas the nitrite test strips did not appear to be useful (SOR C). The combined use of the two rapid test strips did not add to the diagnostic accuracy of the leukocyte test strips alone.”
Reference
Complications of end-stage liver disease: Can Fam Physician. 2016 Jan; 62(1): 44–50. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4721840/
http://jcm.asm.org/cgi/content/full/48/2/456?view=long&pmid=19940047
http://www.aafp.org/afp/2006/0901/p767.html
Click to access wjg-13-6027.pdf