Patients with recurrent or relapsing catheter-related bloodstream infections require treatment that addresses the infection while preserving vascular access, according to a new expert review.
The state-of-the-art review, published in Clinical Infectious Diseases, focuses on treating infections in patients who need long-term vascular access for hemodialysis, chemotherapy, parenteral nutrition and other treatments.
Leonard A. Mermel, DO, ScM, professor of medicine at Brown University in Providence, Rhode Island, and colleagues developed the recommendations based on published research and clinical experience.
“Problems arise when this patient population is not cared for by a team approach,” Dr. Mermel said in an interview with IDSA Reporter. “It is best to manage such patients with a care team involving the patient, primary caregiver, interventional radiology, nursing and the specialty involved (e.g., nutrition team if on total parenteral nutrition, oncology if for chemo or nephrology if for hemodialysis).”
Diagnosis and catheter management
The authors recommend collecting blood cultures from both the catheter and a peripheral vein when a catheter-related bloodstream infection is suspected. If the catheter sample becomes positive at least two hours before the peripheral sample, the difference in time to positivity can help identify the catheter as the source of infection.
In patients with long-term catheters, this diagnostic approach had 98% sensitivity and 89% specificity. However, one study found that sensitivity was only 42% for infections caused by Staphylococcus aureus.
Catheter removal is generally recommended for infections caused by S. aureus, Candida species or mycobacteria. Removal is also recommended for patients with hemodynamic instability, persistent bloodstream infection despite appropriate treatment, endocarditis, infected blood clots or catheter tunnel infections.
For clinically stable patients with infections caused by less virulent organisms and limited alternative vascular access sites, retaining the catheter may be appropriate. The authors generally recommend seven to 14 days of systemic antimicrobial therapy combined with antimicrobial lock therapy when catheter salvage is attempted, with treatment tailored to the causative organism and severity of infection.
Antimicrobial lock therapy involves filling the catheter lumen with a concentrated antimicrobial solution to target microorganisms, including those within biofilms that can form on the catheter's inner surface.
Prevention and clinical implications
The review also identifies antibiotic-treated catheters as a potential strategy for preventing infections. A meta-analysis cited in the review found that antibiotic-treated peripherally inserted central catheters were associated with a 70% lower risk of catheter-related bloodstream infection. Antiseptic-coated catheters did not significantly reduce infection risk.
Five cases presented in the review illustrate challenges in treating recurrent infections, including one involving a child with 25 previous catheter-related bloodstream infections who remained infection-free for at least two years after receiving an antibiotic-treated catheter.
The authors acknowledged that their recommendations rely largely on expert opinion because few randomized trials have examined recurrent infections, catheter salvage or optimal antimicrobial lock therapy. They called for prospective studies comparing infection prevention strategies, treatment durations and catheter replacement approaches.
They concluded that care should be “intentional, well-informed, evidence-based, collaborative and patient-centered.”
The authors reported no funding for the review, although related work received partial support from the U.S. Department of Veterans Affairs. Dr. Mermel and coauthor Kerry L. LaPlante, PharmD, reported industry relationships, including consulting, advisory roles and research funding.
Author insight
Dr. Mermel shared his perspective on the review.
What factors should guide the decision to remove or retain a catheter in patients with recurrent or relapsing catheter-related bloodstream infections?
Dr. Mermel: This should be based on multiple factors, clinical status of the patient (e.g., septic shock), positive or negative follow-up blood cultures, the causative pathogen (e.g., remove cath in nearly all circumstances of S. aureusCRBSI), alternative access sites, etc.
When should clinicians consider antimicrobial lock therapy, and which patients are most likely to benefit?
Dr. Mermel: Lock therapy should be used adjunctively to systemic antimicrobial therapy for CRBSI treatment if the catheter involved is not removed or if only exchanged over a guidewire. For prevention, low threshold for prolonged use in patients with long-term catheters, particularly those with limited alternative access, or history of recurrent/relapsing CRBSIs.
What are the most important steps clinicians can take to prevent recurrent bloodstream infections in patients who require long-term vascular access?
Dr. Mermel: Be sure the patient/caregiver is thoroughly trained and understands the importance of aseptic technique when accessing and caring for the catheter, use antiseptic end caps for CVCs other than ports when not in use, use alcoholic CHG for cleaning the insertion site, use CHG-containing dressing if not a port, decolonize if an S. aureus carrier, consider use of antimicrobial-impregnated catheter and use prophylactic antimicrobial lock therapy.