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Spontaneous bacterial peritonitis
From WikEM
See Peritoneal dialysis-associated peritonitis for PD peritonitis
Contents
Background
- Develops in large, clinically obvious ascites secondary to cirrhosis
- Portal hypertension → bowel edema → normal flora translocates across bowel wall into the peritoneum
- 30% of ascitic patients will develop spontaneous bacterial peritonitis (SBP) in a given year
Causative Agents
- Enterobacter (63%)
- Pneumococcus (15%)
- Entercocci (10%)
- Anaerobes (<1%)
Clinical Features
- Fever (70%)
- Abdominal pain (diffuse) (60%)
- Altered mental status (55%)
- ~15% are asymptomatic
Differential Diagnosis
Diffuse Abdominal pain
- Abdominal aortic aneurysm
- Acute gastroenteritis
- Aortoenteric fisulta
- Appendicitis (early)
- Bowel obstruction
- Bowel perforation
- Gastroparesis
- Diabetic ketoacidosis
- Inflammatory bowel disease
- Mesenteric ischemia
- Pancreatitis
- Peritonitis
- Sickle cell crisis
- Spontaneous bacterial peritonitis
- Volvulus
Evaluation
Consider alternative diagnoses at the same time
SBP Work-Up of Ascitic Fluid via Paracentesis
- Cell count with differential
- Gram stain
- Culture (10cc in blood culture bottle)
- Glucose
- Protein
Diagnosis of SBP via Ascitic Fluid Analysis
Standard Evaluation
- Paracentesis results supporting a diagnosis of SBP:
- Absolute neutrophil count (PMNs) ≥250
- Bacteria on gram stain (single type)
- SAAG > 1.1
- Diagnostic of portal hypertension with 97% accuracy[1]
- SBP rarely develops in patients without portal hypertension
- Protein < 1, Glucose > 50 (otherwise concern for secondary bacterial peritonitis)
For bloody tap, subtract 1 WBC for every 250 RBC[2]
If on Peritoneal Dialysis (CAPD)
SBP if:
- >100 total WBCs OR >50% neutrophils
If on Nightly APD
SBP if:
- >50% neutrophils
- Amylase (>100 suggestive of intra-abdominal process)
Spontaneous versus secondary bacterial peritonitis
- Importance of distinction
- Mortality of secondary bacterial peritonitis (eg. perforated appendicitis, cholecystitis) ~100% if treatment is only antibiotics without surgery
- Mortality of unnecessary surgery in patients with SBP ~80%
- Laboratory findings
- Secondary bacterial peritonitis strongly suggested by:
- Neutrocytic fluid (PMN ≥250) with two or more of the following:
- Total protein concentration >1 g/dL (10 g/L)
- Glucose concentration <50 mg/dL (2.8 mmol/L)
- LDH greater than upper limit of normal for serum
- Ascitic alk phos >240
- Gram stain
- Large numbers of different bacterial forms
- Neutrocytic fluid (PMN ≥250) with two or more of the following:
- Secondary bacterial peritonitis strongly suggested by:
- Imaging
- If evidence of secondary bacterial peritonitis obtain abdominal imaging
- If no evidence of free air or contrast extravasation then surgery is not indicated
- If evidence of secondary bacterial peritonitis obtain abdominal imaging
Management
Antibiotics
- 3rd-generation cephalosporin:
- Cefotaxime 2g IV q8hr or Ceftriaxone 1-2g IV q12-24hr
- If beta-lactam allergy, ciprofloxacin 400mg IV q12hr
Albumin
Reduces renal failure and hospital mortality if given within 6 hours[3]
- 1.5gm/kg at diagnosis; 1gm/kg on day 3
- Give for all or (larger effect) if creatinine >1mg/dL, BUN >30mg/dL, or T Bili >4mg/dL
Disposition
- Most admitted
- Can consider discharge with PO antibiotics if has mild, uncomplicated disease and close follow up
See Also
References
- ↑ Runyon BA, Montano AA, Akriviadis EA, et al. The serum-ascites albumin gradient is superior to the exudate-transudate concept in the differential diagnosis of ascites. Ann Intern Med 1992; 117:215.
- ↑ Hoefs JC "Increase in ascites white blood cell and protein concentrations during diuresis in patients with chronic liver disease."Hepatology. 1981;1(3):249. PMID 7286905
- ↑ Jamtgaard, et al. Does albumin infusion reduce renal impairment and mortality in patients with SBP. Annals of EM. April 2016. 67(4):458-458.
