Treatment of catheter-related bacteraemia with an antibiotic lock protocol: effect of bacterial pathogen.

BACKGROUND: The standard therapy of dialysis catheter-related bacteraemia involves both systemic antibiotics and catheter replacement. We reported recently that instillation of an antibiotic lock (highly concentrated antibiotic solution) into the catheter lumen after dialysis sessions, in conjunction with systemic antibiotics, can successfully treat many episodes of catheter-related bacteraemia without requiring catheter removal. The present study evaluated whether the likelihood of achieving a cure with this protocol depends on the type of pathogen. METHODS: This was a historically controlled interventional study of an antibiotic lock protocol for the treatment of catheter-related bacteraemia. We analysed prospectively the likelihood of clinical cure (fever resolution and negative surveillance cultures) with an antibiotic lock protocol among patients with dialysis catheter-related bacteraemia. In addition, infection-free catheter survival was evaluated for up to 150 days, and compared with that observed among patients managed with routine catheter replacement. RESULTS: Overall, the antibiotic lock protocol was successful in 33 of 47 infected patients (70%) with catheter-related bacteraemia. The likelihood of a clinical cure was 87% for Gram-negative infections, 75% for Staphylococcus epidermidis infections, and only 40% for Staphylococcus aureus infections (P = 0.04). The median infection-free catheter survival with the antibiotic lock protocol was longer than that observed among patients with routine catheter replacement (154 vs 71 days, P = 0.02). CONCLUSIONS: The clinical success of an antibiotic lock protocol in eradicating catheter-related bacteraemia while salvaging the catheter is highly dependent on the bacterial pathogen. Thus, the overall success rate in an individual dialysis programme will depend on the relative frequencies of different bacterial pathogens.

Management of hemodialysis catheter-related bacteremia with an adjunctive antibiotic lock solution.

BACKGROUND: Tunneled dialysis catheters are complicated by frequent systemic infections. Standard therapy of catheter-associated bacteremia involves both systemic antibiotics and catheter replacement. Recent data suggest that biofilms in the catheter lumen are responsible for the bacteremia, and that instillation of an antibiotic lock (highly concentrated antibiotic solution) into the catheter lumen after dialysis sessions can eradicate the biofilm. METHODS: We analyzed prospectively the efficacy of an antibiotic lock protocol, in conjunction with systemic antibiotics, for treatment of patients with dialysis catheter-associated bacteremia without catheter removal. Protocol success was defined as resolution of fever and negative surveillance cultures one week following completion of the protocol. Protocol failure was defined as persistence of fever or surveillance cultures positive for any pathogen. In addition, infection-free catheter survival was compared to that observed in institutional historical control patients treated with catheter replacement. RESULTS: Blood cultures were positive in 98 of 129 of episodes (76%) in which patients dialyzing with a catheter had fever or chills. Protocol success occurred in 40 of 79 infected patients (51%) treated with the antibiotic lock. Protocol failure occurred in 39 cases (49%): 7 had persistent fever, 15 had positive surveillance cultures (9 for Candida and 6 for bacteria), and 17 required catheter removal due to malfunction. Each of the pathogens in the surveillance cultures was different from the original pathogen in that patient. Eight of the 9 secondary Candida infections and all 6 secondary bacterial infections resolved after catheter exchange and specific antimicrobial treatment. Overall catheter survival with the antibiotic lock protocol was similar to that observed among patients managed with catheter replacement (median survival, 64 vs. 54 days, P = 0.24). CONCLUSIONS: Use of an antibiotic lock, in conjunction with systemic antibiotic therapy, can eradicate catheter-associated bacteremia while salvaging the catheter in about one half of cases. Moreover, this management approach offers clinical advantages over routine catheter exchange.