Spontaneous bacterial peritonitis

Clinical Manifestations

• Develops in large, clinically obvious ascites 2/2 cirrhosis
• Fever - 70%
• Abdominal pain (diffuse) - 60%
• Altered mental status - 55%
• ~15% of patients have no signs/symptoms!

Diagnosis

• Paracentesis results supporting a diagnosis of SBP:
  • Absolute neutrophil count > 250PMNs/microL
  • SAAG > 1.1
  • Total protein < 1 and Glucose > 50 (otherwise concern for 2^o bacterial peritonitis)
• There is no platelet count or INR that is a contraindication to paracentesis

Distinction of spontaneous from secondary bacterial peritonitis

• Importance
  • Mortality of 2^o bacterial peritonitis approaches 100 percent if tx is only antibiotics without sx
  • Mortality of unncessary ex lap in patient w/ SBP and wrongly suspected 2^o bacterial peritonitis ~80%
• Laboratory findings
  • Neutrocytic fluid (PMN ≥250) with two or more of following = strong evidence of 2^o bacterial peritonitis:
    • 1. Total protein concentration >1 g/dL (10 g/L)
    • 2. Glucose concentration <50 mg/dL (2.8 mmol/L)
    • 3. LDH greater than upper limit of normal for serum

• • • Should strongly suspect if ascitic alk phos >240
  • Gram Stain
    • Large numbers of different bacterial forms
• Imaging
  • If evidence of 2^o bacterial peritonitis obtain abdominal imaging
    • If no evidence of free air or contrast extravasation then surgery is not indicated

Treatment

• Antibiotics
  • SBP
    • Broad-spectrum covering gram + and gram -
      • 3rd-generation cephalosporin is agent of choice:
        • Cefotaxime 2g IV q8hr or Ceftriaxone 1-2g IV q12-24hr
      • If beta-lactam allergy consider ciprofloxacin 400mg IV q12hr
  • 2^o bacterial peritonitis
    • 3rd-generation cephalosporin + metronidazole
• Albumin
  • Decreases incidence of renal failure
  • 1.5g/kg at time of diagnosis and 1g/kg on day 3

Source

Rosen's, UpToDate, Thomsen TW. Paracentesis. N Engl J Med 2006; 355