Peritoneal infections

Peritoneal dialysis related infections include infection of the catheter exit site, subcutaneous pathway, or effluent. Exit-site infections, predominately owing to Staphylococcus aureus, are defined as purulent drainage at the exit site, although erythema may be a less serious type of exit-site infection. Tunnel infections are underdiagnosed clinically, and sonography of the tunnel is useful to delineate the extent of the infection and to evaluate response to antibiotic therapy. S aureus infections occur more frequently in S aureus carriers and immunosuppressed patients and can be reduced by mupirocin prophylaxis either intranasally or at the exit site. Patients with peritonitis present with cloudy effluent and usually pain, although 6% of patients may initially have pain without cloudy effluent. A white blood cell count of 100 or greater per microL, 50% of which are polymorphonuclear cells, has long been the hallmark of peritonitis. Empiric therapy is controversial, with some recommending cefazolin and others vancomycin (with cefatazidime for Gram-negative coverage). The choice should depend on the center's antibiotic sensitivity profile; those centers with a high rate of Enterococcus- or methicillin resistant organisms should use vancomcycin. Peritonitis episodes occurring in association with a tunnel infection with the same organism seldom resolve with antibiotics and require catheter removal. Other indications for catheter removal are refractory peritonitis, relapsing peritonitis, tunnel infection with inner-cuff involvement that does not respond to antibiotic therapy (based on ultrasound criteria), fungal peritonitis, and enteric peritonitis owing to intra abdominal pathology. Centers can reduce dialysis related infections to very low levels by proper catheter selection and insertion, careful selection and training of patients, avoidance of spiking techniques, and use of antibiotic prophylaxis against S. aureus. Further research is required to identify methods to reduce the risk of enteric peritonitis.