What is the treatment for an Acinetobacter infection related to a Peripherally Inserted Central Catheter (PICC)?

Treatment of Acinetobacter Peritoneal Dialysis Catheter Infection

For Acinetobacter infections related to a peritoneal dialysis catheter, you should remove the catheter promptly and initiate appropriate systemic antimicrobial therapy based on susceptibility testing. 1

Immediate Management

Catheter Removal

• Remove the infected catheter immediately as established Acinetobacter infections often require catheter removal for cure 1
• Acinetobacter species are specifically listed among pathogens (alongside P. aeruginosa, Stenotrophomonas maltophilia, and Bacillus species) that respond poorly to antimicrobial treatment alone and necessitate prompt catheter removal 1
• Do not attempt catheter salvage with antibiotic lock therapy or systemic antibiotics alone for Acinetobacter infections 1

Culture and Susceptibility Testing

• Obtain blood cultures and peritoneal fluid cultures before initiating antibiotics 1
• Send specimens for identification and susceptibility testing to guide definitive therapy 1
• Knowledge of local susceptibility patterns is critical, as multidrug-resistant (MDR) Acinetobacter is increasingly common 2, 3

Empirical Antimicrobial Therapy

Initial Antibiotic Selection

• Start empirical therapy with an antipseudomonal carbapenem (imipenem, meropenem, or doripenem) as these are the mainstay of treatment for Acinetobacter baumannii infections 2, 3
• Alternative empirical options include:
  • Ceftazidime or cefepime (fourth-generation cephalosporin) 1
  • Antipseudomonal penicillin with beta-lactamase inhibitor 1
  • Consider adding an aminoglycoside for synergy in severe infections 1

For Suspected Multidrug-Resistant Strains

• If MDR Acinetobacter is suspected based on local epidemiology or prior patient history, consider:
  • Polymyxin E (colistin) or polymyxin B 2, 3
  • Sulbactam (often combined with ampicillin) 2, 3
  • Tigecycline - though note that tigecycline resistance can develop during treatment in Acinetobacter via MDR efflux pumps 4, 2
• Combination therapy is recommended for carbapenem-resistant Acinetobacter and should include two agents with different mechanisms of action 3, 5

Definitive Therapy

Antibiotic Adjustment

• Modify therapy based on susceptibility results within 48-72 hours 1
• If carbapenem-susceptible, continue with imipenem or meropenem as monotherapy 2, 3
• If carbapenem-resistant, continue combination therapy with polymyxins plus either:
  • A carbapenem (for synergy despite resistance) 3, 5
  • Sulbactam 2, 3
  • Tigecycline 2, 3
  • An aminoglycoside 2, 3

Duration of Treatment

• Treat for at least 14 days after catheter removal and first negative blood culture 1
• Extend to 4-6 weeks if bacteremia persists >72 hours after catheter removal or if complications develop (endocarditis, septic thrombophlebitis) 1
• Continue treatment for at least 7 days after defervescence in neutropenic patients 1

Monitoring and Follow-Up

Clinical Reassessment

• Reassess clinical response after 2-3 days of therapy 1
• Obtain surveillance blood cultures if bacteremia persists despite appropriate therapy and source control 1
• Monitor closely for relapse, as tigecycline resistance can emerge during treatment in Acinetobacter infections 4
• If relapse is suspected, obtain repeat cultures and test all isolates for susceptibility 4

Catheter Replacement

• If continued peritoneal dialysis access is needed, place a new catheter at a different site only after infection has cleared 1
• Do not exchange the catheter over a guidewire in the setting of Acinetobacter infection 1

Critical Pitfalls to Avoid

• Do not attempt catheter salvage - unlike coagulase-negative staphylococcal infections that may respond to antibiotics alone, Acinetobacter infections require catheter removal 1
• Do not use monotherapy for carbapenem-resistant strains - combination therapy is essential to prevent treatment failure 3, 5
• Do not rely on older susceptibility data - resistance patterns in Acinetobacter change rapidly, and local antibiograms must guide empirical choices 2, 3, 6
• Do not delay catheter removal - waiting beyond 72 hours significantly increases mortality risk 1
• Do not use tigecycline as monotherapy without close monitoring, as resistance can develop during treatment 4