What is the recommended approach for diagnosing and treating peritonitis in a peritoneal dialysis patient?

From the Guidelines

The diagnosis of peritonitis in peritoneal dialysis patients should be promptly initiated with the collection of peritoneal fluid for analysis, and treatment should start immediately with empiric antibiotics. The diagnosis is confirmed when peritoneal fluid contains more than 100 white blood cells/mm³ with at least 50% neutrophils.

Key Considerations

• The patient's clinical stability and the timing of the peritoneal fluid collection are crucial, as peritonitis can transiently change the patient's transport status and decrease ultrafiltration, potentially affecting the accuracy of dialysate clearance measurements 1.
• Measurements of peritoneal solute clearance should be obtained when the patient is clinically stable and at least 1 month after resolution of an episode of peritonitis, to ensure accurate assessment of dialysis adequacy.
• Repeated measurements of peritoneal urea clearance or residual kidney function (RKF) may be necessary when clinically indicated, such as in cases of failure to thrive or suspected nonadherence to the prescription.

Treatment Approach

• Empiric antibiotic therapy should be administered intraperitoneally, typically combining a first-generation cephalosporin with an aminoglycoside, to cover both gram-positive and gram-negative organisms.
• Antibiotic therapy should be adjusted based on culture results and continued for 14-21 days.
• The peritoneal dialysis catheter should be preserved if possible, but removal may be necessary for refractory infections, fungal peritonitis, or relapsing episodes.

Monitoring and Follow-up

• Patients should be monitored for clinical improvement, with repeat cell counts performed after 3-5 days.
• The patient's RKF and peritoneal solute clearance should be reassessed after an episode of peritonitis to determine the need for adjustments to the dialysis prescription. This approach is critical because peritonitis remains a major complication of peritoneal dialysis that can lead to technique failure, peritoneal membrane damage, and increased mortality if not promptly and effectively treated.

From the Research

Diagnosis of Peritonitis in Peritoneal Dialysis Patients

• The diagnosis of peritonitis among peritoneal dialysis (PD) patients is based on clinical presentation, dialysis effluent white blood cell (WBC) count, and dialysis effluent culture 2.
• Peritoneal fluid WBC count is very important in the initial diagnosis of peritonitis, with a recommended cutoff of 230/μL providing specificity of 89% and good positive and negative likelihood scores 2.
• Clinical manifestations such as fever, increased C-reactive protein, and abdominal pain should also be considered in the diagnosis of peritonitis 2, 3.

Treatment of Peritonitis in Peritoneal Dialysis Patients

• The treatment of peritonitis in PD patients typically involves the use of antibiotics, with the choice of antibiotic depending on the causative organism and its susceptibility to different antibiotics 3, 4.
• A combination of antibiotics may be used empirically, with the regimen adjusted based on the results of culture and sensitivity testing 3.
• The use of antibiotics such as cefazolin, tobramycin, and vancomycin is recommended, as they are stable in peritoneal dialysis solutions and can be administered in the PD bag 4.
• However, antibiotics such as amoxicillin, cefepime, ceftazidime, and imipenem must be used with caution due to their lack of stability in PD solutions 4.

Management of Peritonitis in Peritoneal Dialysis Patients

• The management of peritonitis in PD patients requires careful consideration of several factors, including the choice of antibiotic, the duration of treatment, and the need for catheter removal 3, 5.
• Common mistakes and misconceptions in the management of peritonitis can compromise treatment success, and suggestions for management based on the best available literature are recommended 5.
• The collection of PD effluent specimens for white blood cell count, Gram stain, culture, and sensitivity is an important aspect of management, and should be done safely and according to best practices 6.

Collection of PD Effluent Specimens

• The collection of PD effluent specimens is a critical step in the diagnosis and management of peritonitis in PD patients 6.
• Nephrology nurses and home dialysis nurses should be aware of the best practices for PD effluent specimen collection, including how to collect specimens safely, how to proceed with collection, and how to collect specimens for assessment 6.
• However, there is limited evidence in the literature to answer several questions related to PD effluent specimen collection, and nursing practice may vary within and among countries 6.