Diagnosis
Blood infections are often catheter-related. Peritoneal catheter infections usually present with abdominal pain and cloudy CAPD fluid.
Epidemiologic Risks
I think, but I could be wrong, that being on dialysis is a risk.
Microbiology
With hemodialysis, it's S. aureus, and to a lesser extent anything. Patients get colonized in the nose, which will precede bacteremia (nose has staph, the nose is picked, finger then touches graft, then needle drags staph into the vascular space).
Stenotrophomonas, waterborne, can be a problem in dialysis units with line infections (PubMed).
With CAPD it tends to be skin flora, especially coagulase-negative Staphylococcus. But anything can sneak into the peritoneal space. We had one lady whose cat slept in her dialysis bag warmer. She got Pasteurella peritonitis. Really.
Empiric Therapy
Vancomycin PLUS some sort of gram-negative rod coverage: quinolone OR third-generation cephalosporin OR an aminoglycoside. I leave intraperitoneal dosing to the nephrologist.
The type and duration of therapy depend on what grows.
But. Never. Ever. Never use vancomycin for MSSA because it is more convenient because it is also markedly less effective: "Treatment failure was more common among patients receiving vancomycin (31.2% vs. 13%) (PubMed)."
Pearls
Weekly nasal mupirocin prevents staphylococcal aureus bacteremia in hemodialysis. As does a baby aspirin.
Lymphocyte assays are better than a skin test for diagnosing latent TB in dialysis patients, something to consider should the patient be heading towards a transplant (PubMed).
The line usually can't be salvaged and will need to be removed.
A PET scan may be the best way to diagnose graft infections and subsequent silent metastatic foci (PubMed). But try getting it paid for in the US.
If you grow bowel flora in the peritoneal fluid of a CAPD patient, say, a Bacteroides or Escherichia coli or Enterococcus as examples, think of bowel perforation. The catheter has eroded through the bowel wall. Guaranteed.
Last Update: 06/21/18.