Spontaneous bacterial peritonitis
From IDWiki
Background
- Primary infection of the ascitic fluid, diagnosed by ascites fluid with positive culture or with neutrophil count greater than 250
Microbiology
- Escherichia coli (43%)
- Klebsiella pneumoniae (11%)
- Streptococcus pneumoniae (9%), particularly affecting people with HIV and prepubertal girls
- Other streptococcal species (19%)
- Enterobacteriaceae (4%)
- Staphylococcus (3%)
- Pseudomonas (1%)
- Miscellaneous (10%)
Pathophysiology
- Intestinal bacterial overgrowth with increased intestinal permeability leads to translocation to intestinal lymph notes and bloodstream, which results in hematogenous seeding to ascitic fluid
- Only occurs in portal hypertension, not in other causes of ascites
Risk Factors
- Previous history of SBP
- Upper GI bleed
- Low sciatic protein
- Child-Pugh class
Clinical Manifestations
- Asymptomatic in 10%
- Fever (70%)
- Abdominal pain (60%)
- Hepatic encephalopathy (50%)
- Abdominal tenderness, usually without rigidity (50%)
- Diarrhea (30%)
- Ileus (30%)
- Shock (20%)
- Hypothermia (15%)
Variants
- Culture-negative neutrocytic ascites: usually caused by difficult-to-treat organisms like tuberculosis, and non-infective sources
- Monomicrobial non-neutrocytic bacterascites: early bacterial colonization
- Polymicrobial bacterascites: usually from traumatic paracentesis
Prognosis and Complications
- In-hospital mortality of about 33% in hospital
- 58% 6-month mortality
Investigations
- Diagnostic paracentesis with ascitic fluid sent for cell count with differential and culture
- Neutrophil count < 250 rules it out
- Culture usually monomicrobial
- Repeat paracentesis at 48h if ongoing concern
Management
- Ceftriaxone 1-2g IV q24h + albumin 1.5 g/kg on day 1 and 1 g/kg on day 3
Prevention
- Prophylaxis is indicated after even a single episode of SBP
- TMP-SMX SS or DS PO daily
- Norfloxacin 400 mg PO daily
- Ciprofloxacin 500 mg PO daily
- Doxycycline 100 mg PO daily is under investigations as an alternative1 (see abstract)
- Possibly a role for primary prophylaxis
References
- ^ Ngoc Nguyen, Matthew Crotty, Edward A. Dominguez, Adil Habib, Hector E. Nazario, Zahid M. Vahora, Parvez S. Mantry, Jessiva Rago, Melanie Proffitt, Maisha N. Barnes, Ashwini Mehta, Mangesh R. Pagadala, Jeffrey S. Weinstein. Doxycycline for the prevention of spontaneous bacterial peritonitis. The Liver Meeting. 2023.