What are the next steps for treating a patient with recurrent Central Line-Associated Bloodstream Infection (CLABSI) due to Staphylococcus epidermidis, currently on vancomycin, with a history of mitochondrial disease and Deep Vein Thrombosis (DVT), and experiencing migraine exacerbations, fatigue, and urinary retention?

Management of Recurrent Staph Epidermidis CLABSI in TPN-Dependent Patient

Given this patient's recurrent Staph epidermidis CLABSI despite prior salvage attempts, the port should be removed and replaced with a PICC line at a different site, followed by 10-14 days of systemic vancomycin therapy after catheter removal. 1, 2

Immediate Catheter Management Decision

Port removal is indicated in this case based on the following criteria:

• Recurrent infection despite prior salvage therapy is a clear indication for catheter removal 1, 2
• While coagulase-negative staphylococci (including Staph epidermidis) are the only organisms where salvage may be attempted, this patient has already failed prior salvage treatment 1
• Salvage therapy should only be attempted once for uncomplicated CNS-CLABSI in patients with limited access options 1
• The patient's symptoms (migraine exacerbations, fatigue) despite being afebrile and without leukocytosis suggest ongoing low-grade infection that has not cleared with previous treatment 1

Key Pitfall to Avoid

Do not attempt repeated salvage therapy for recurrent CNS-CLABSI. Guidelines specify that if blood cultures remain positive 72 hours after initiation of appropriate therapy, the catheter must be removed 1, 2. This patient has demonstrated treatment failure by having recurrent positive cultures.

Antibiotic Management

Continue vancomycin for 10-14 days after port removal:

• For uncomplicated coagulase-negative staphylococcal CLABSI, 7-10 days of therapy is recommended if the catheter is removed 2
• However, given this patient's recurrent infections and complex medical history (mitochondrial disease, TPN dependence), extend to 10-14 days 1, 2
• Vancomycin remains appropriate as empiric therapy for CNS-CLABSI 1
• Confirm vancomycin susceptibility and consider checking vancomycin trough levels to maintain 15-20 mcg/mL 3

Important Consideration for Vancomycin Heteroresistance

Recent evidence shows that 39% of Staph epidermidis isolates from CLABSIs demonstrate vancomycin heteroresistance, which is associated with treatment failure and persistent bacteremia 4. If this patient continues to have positive cultures despite appropriate vancomycin therapy, request population analysis profiling for heteroresistance testing and consider alternative agents such as daptomycin or linezolid 1.

Vascular Access Strategy

Insert a PICC line at a different anatomical site after port removal:

• The port should be removed at a different site from where the new PICC will be placed to avoid seeding the new line 1
• Do not perform guidewire exchange in the setting of active bacteremia 1
• Wait until blood cultures are negative before placing new long-term access if clinically feasible 2
• Given the patient's history of difficult port placement and TPN dependence, involve interventional radiology early for optimal PICC placement 1

Follow-Up Blood Culture Protocol

Obtain repeat blood cultures as follows:

• Draw cultures from both the port (before removal) and peripheral site 1, 2
• Repeat blood cultures 48-72 hours after initiating appropriate antibiotic therapy to document clearance 1, 2
• Obtain blood cultures one week after completing antibiotic therapy to confirm eradication 3
• If any cultures remain positive beyond 72 hours of appropriate therapy, this confirms complicated CLABSI requiring extended therapy (4-6 weeks) 2, 3

Evaluation for Complicated Infection

Rule out metastatic complications given recurrent infections:

• The transesophageal echocardiogram (TTE) was negative, which is reassuring, but consider transesophageal echocardiography (TEE) if bacteremia persists, as it has higher sensitivity for detecting vegetations 2
• Evaluate for suppurative thrombophlebitis with vascular imaging of the catheter site 1, 2
• If any metastatic complications are identified, extend antibiotic therapy to 4-6 weeks 2, 3

Prevention Strategies for Future Access

Implement strict CLABSI prevention measures for the new PICC:

• Use maximal sterile barrier precautions during insertion 2
• Perform cutaneous antisepsis with chlorhexidine 2
• Transition to closed infusion systems for TPN administration, as closed systems reduce CLABSI rates by 65% compared to open systems (2.21 vs 6.40 per 1000 catheter-days) 1
• Ensure meticulous hand hygiene before all line manipulations 2
• Consider prophylactic antibiotic locks for future long-term access given this patient's recurrent infections, though this should be discussed with infectious disease specialists 1

Addressing Concurrent Symptoms

The patient's urinary retention and migraine exacerbations warrant evaluation:

• Urinary retention despite bladder stent may be related to systemic infection or medication effects from vancomycin 5
• Monitor renal function closely given vancomycin use and history of urinary issues 5
• The migraines and fatigue may represent subtle manifestations of ongoing bacteremia in this immunocompromised patient with mitochondrial disease 1