Peritoneal dialysis-associated peritonitis

Background

Microbiology

• Gram-positive bacteria (45%)
  • Coagulase-negative staphylococci
  • Staphylococcus aureus
  • Streptococci
  • Diphtheroids
• Gram-negative bacteria (15%), especially if underlying GI pathology
• Mixed bacterial (1-2%)
• Fungal (1%), particularly Candida
• Tuberculosis (<1%)

Pathophysiology

• Acquired from catheter, exit site, dialysate fluid, or transmural migration

Epidemiology

• On average one episode per patient per year

Clinical Manifestations

• Peritonitis, with diffuse abdominal pain and tenderness and cloudy or purulent dialysate
• Often afebrile
• Dialysate may have elevated WBCs >100 cells/mcL with >50% neutrophils

Diagnosis

• Aspirate dialysate, then centrifuge and inoculate into blood culture bottles (for both aerobic and anaerobic organisms)

Management

• Empiric treatment should cover coagulase-negative staphylococci and gram-negatives, so vancomycin plus ceftriaxone or ceftazidime would be reasonable
• Intraperitoneal antibiotics are preferred unless systemic infection or bacteremia
• May attempt to salvage the catheter, especially for less virulent organisms like coagulase-negative staphylococci
• Indications for catheter removal include
  • Difficult-to-treat organisms (Candida, Staphylococcus aureus, resistant Gram-negatives like Pseudomonas or Stenotrophomonas)
  • Bowel perforation
  • Relapse with same organism within a month
  • Clinical failure despite 5 days of appropriate antibiotics
  • Exit site infection
• Duration 14 to 21 days, or 1 week after catheter removal

Further Reading

• ISPD Peritonitis Recommendations: 2016 Update on Prevention and Treatment. Perit Dial Int. 2016;36:481. doi: 10.3747/pdi.2016.00078
• ISPD Catheter-Related Infection Recommendations: 2017 Update. Perit Dial Int. 2017;37:141-154. doi: 10.3747/pdi.2016.00120