What is the treatment for exit site infections in Continuous Ambulatory Peritoneal Dialysis (CAPD)?

Treatment of Exit Site Infections in CAPD

For exit site infections in CAPD patients, obtain cultures from any drainage before initiating empiric antibiotics covering Gram-positive organisms (typically for 7-14 days), with catheter removal reserved only for refractory cases or specific high-risk organisms like Pseudomonas or Staphylococcus aureus that fail medical therapy. 1

Initial Assessment and Culture Collection

• Obtain cultures from exit site drainage before starting antibiotics to guide definitive therapy and avoid antibiotic resistance 1
• Collect blood cultures if there are signs or symptoms of systemic infection (fever, chills, hemodynamic instability) 1
• Swab any exudate at the exit site for culture and Gram staining 1

Empiric Antibiotic Therapy

Start empiric antibiotics targeting Gram-positive organisms immediately after obtaining cultures 1:

• The most common pathogens are Staphylococcus aureus, coagulase-negative Staphylococcus, Pseudomonas aeruginosa, and Escherichia coli 2, 3
• Empiric coverage should focus on Gram-positive organisms, particularly staphylococci 1
• Modify antibiotics once culture and sensitivity results are available 1

Treatment Duration

• Standard treatment duration is 7-14 days for uncomplicated exit site infections 1
• Continue therapy for at least 2 days after signs and symptoms resolve, though complicated infections may require longer treatment 4

Catheter Management Strategy

The catheter typically does NOT require removal for exit site infections alone, but management depends on the organism and response to therapy 1:

Indications for Catheter Removal:

• Pseudomonas aeruginosa infections: Up to 28% require catheter removal; these infections have uniformly poor outcomes regardless of treatment 2, 5
• Staphylococcus aureus infections: Approximately 35% require catheter removal if refractory to antibiotics 2, 3
• Mycobacterial infections: Up to 40% require catheter removal 2
• Failure to respond to appropriate antibiotic therapy after adequate treatment course 1
• Development of tunnel infection or peritonitis 1

Salvage Procedures Before Removal:

• For antibiotic-resistant S. aureus exit site infections, consider deroofing and outer cuff shaving, which resolves approximately 48% of cases 3
• If tunnel infection develops but antibiotics fail, consider catheter exchange with a new subcutaneous tunnel to preserve the venous access site 1

Adjunctive Diagnostic Tools

• Consider ultrasonography to assess infection severity and predict treatment response 5
• A sonolucent zone around the external cuff >1 mm thick after antibiotic treatment indicates poor prognosis and likely need for catheter removal 5
• Involvement of the proximal cuff on ultrasound is associated with unfavorable outcomes 5

Organism-Specific Considerations

Pseudomonas aeruginosa:

• Oral ciprofloxacin 500 mg twice daily plus local exit site care resolves approximately 83% of cases 6
• However, 17% require catheter removal, and 22% develop peritonitis 2-9 months after apparent resolution 6
• All Pseudomonas ESI cases have poor clinical outcomes regardless of sonographic findings 5

Staphylococcus aureus:

• Approximately 50% of S. aureus peritonitis cases are associated with preceding exit site infection 2
• Consider early aggressive intervention including cuff shaving for refractory cases 3

Critical Pitfalls to Avoid

• Do not delay culture collection before starting antibiotics, as this compromises ability to tailor therapy 1
• Do not continue ineffective therapy indefinitely—if no improvement after appropriate antibiotic course, proceed to catheter removal or salvage procedures 1
• Recognize that Gram-negative ESI (especially Pseudomonas) has lower cure rates and higher risk of catheter loss compared to Gram-positive infections 2, 5
• Be aware that up to 20% of all peritonitis cases are preceded by exit site infection, making aggressive ESI treatment critical for preventing this serious complication 2

Prevention Considerations

• Topical gentamicin prophylaxis is effective for preventing most exit site infections, including Gram-negative ESI, and should be considered in areas with high Gram-negative peritonitis incidence 2
• However, long-term use may lead to resistance (up to 14% for gentamicin-resistant Gram-negative organisms) 2