What are the causes, prevention, and treatment of peritoneal dialysis (PD)-associated peritonitis in a patient undergoing PD, particularly in an intensive care unit (ICU) setting?

PD-Associated Peritonitis: Causes, Prevention, and Treatment

Causes and Microbiology

Peritonitis in PD patients is primarily caused by bacterial contamination during exchanges, with Gram-positive organisms accounting for approximately 70% of cases and Gram-negative organisms 25%. 1

Primary Causative Organisms

• Gram-positive bacteria (69.9% of cases): Most common pathogens requiring empirical coverage 1
• Gram-negative organisms (25.4% of cases): Including Pseudomonas species which must be covered empirically 2
• Fungal peritonitis: Candida species are the most common fungal cause, with Aspergillus less frequent but well-established 3
• Enteric organisms: Associated with diarrhea through bacterial translocation from the intestine 2

Risk Factors and Pathways

• Exit-site and tunnel infections can progress to peritonitis and represent a major pathway for infection 3
• Catheter-related mechanical problems increase infection risk 3
• Inadequate dialysis dosing may increase infection susceptibility through uremic complications 4

Prevention Strategies

Water avoidance during showering with stoma bag coverage combined with topical mupirocin ointment represents the most effective exit-site care protocol, reducing catheter-related infections by 85% (from 0.71 to 0.11 episodes per patient-year). 5

Exit-Site Care (Highest Priority)

• Prevent water exposure during showering using stoma bag coverage over the exit site 5
• Apply mupirocin ointment locally to the exit site (superior to gentamicin ointment) 5
• Avoid environmental water-related pathogens from distribution systems 5

Prophylactic Measures

• Antibiotic prophylaxis for invasive procedures 6
• Antifungal prophylaxis whenever systemic antibiotics are prescribed to prevent fungal peritonitis 6
• Nasal mupirocin for Staphylococcus aureus carriers 6

System-Level Prevention

• Monthly patient evaluations reviewing ultrafiltration, clearance, quality of life, and adherence 4
• Monitor peritonitis rates and causative organisms at the unit level 2
• Target <0.5 episodes per patient-year as the quality benchmark 1
• Achieve 75% 2-year technique survival rate as the safety standard 4

Treatment

Initiate empirical intraperitoneal antibiotics covering both Gram-positive and Gram-negative organisms (including Pseudomonas) immediately after obtaining peritoneal fluid cultures. 2

Empirical Antibiotic Regimen

• Intraperitoneal vancomycin PLUS gentamicin is the recommended first-line empirical therapy with sustained efficacy and no evidence of driving resistance over 5 years 1
• IP route is superior to IV administration for reducing treatment failure (RR 3.52,95% CI 1.26-9.81) 7
• Continuous versus intermittent IP dosing have similar efficacy; either schedule is acceptable 7

Glycopeptide Advantage

• IP glycopeptides (vancomycin or teicoplanin) are more likely to achieve complete cure compared to first-generation cephalosporins (RR 1.66,95% CI 1.01-2.72), though effects on primary response and relapse are uncertain 7
• Vancomycin resistance averages only 2% with this protocol 1
• Gentamicin resistance averages 8% of Gram-negative organisms 1

Treatment Duration

• Standard duration: Adjust based on culture results and clinical response 7
• Extended 21-day treatment (versus 10 days) shows uncertain benefit for preventing relapse but may increase ototoxicity risk 7

Refractory or Complicated Peritonitis

Remove the PD catheter immediately for fungal peritonitis, refractory peritonitis, recurrent peritonitis, or refractory exit-site/tunnel infections, with temporary hemodialysis support. 2

Indications for Catheter Removal

• Fungal peritonitis: Absolute indication for immediate removal 2
• Refractory peritonitis: Failure to respond to appropriate antibiotics 2
• Recurrent peritonitis: Multiple episodes despite treatment 2
• Refractory exit-site or tunnel infections: Not responding to antimicrobials 2

Catheter Replacement Strategy

• Simultaneous catheter removal and replacement is superior to urokinase for relapsing/persistent peritonitis (RR 2.35,95% CI 1.13-4.91) 7

Post-Peritonitis Management

• Reevaluate residual renal function after each peritonitis episode as it can significantly decline 2
• Recognize temporary high transporter state during peritonitis which decreases ultrafiltration and may distort clearance measurements 2
• Wait at least 1 month after peritonitis resolution before performing diagnostic tests 2

Critical Pitfalls to Avoid

• Delaying empirical antibiotics while awaiting culture results increases morbidity and mortality 2
• Using IV instead of IP antibiotics results in higher treatment failure rates 7
• Failing to cover Pseudomonas in empirical regimens leads to inadequate initial treatment 2
• Delaying catheter removal in fungal peritonitis worsens outcomes and increases mortality 2
• Allowing water exposure to exit sites dramatically increases infection rates 5
• Frequent peritonitis (>0.5 episodes/patient-year) causes excessive protein losses leading to severe malnutrition and is a formal indication for switching to hemodialysis 3, 4

Outcomes and Prognosis

• Peritonitis causes technique failure in approximately 16% of patients, requiring transfer to hemodialysis 3, 4
• Improved exit-site care protocols reduce peritonitis rates from 0.40 to 0.19 episodes per patient-year 5
• Transfer to hemodialysis decreases from 31% to 7.3% with optimal prevention protocols 5
• PD patients average 1.8 hospitalizations per year, with peritonitis being a major contributor 4