Treatment of long-term intravascular catheter-related bacteraemia with antibiotic-lock therapy

Background: Bacteraemia is a major complication associated with the use of long-term intravascular catheters. Conservative treatment using antibiotic-lock therapy (ALT) has been shown to be useful in some studies, but the evidence supporting its impact in clinical care is still scarce. Methods: We evaluated the outcome of the episodes of catheter-related bacteraemia (CRB) associated with long-term intravascular devices used for chemotherapy or parenteral nutrition and that were managed with ALT during a 44 month period in our hospital. Episodes of CRB associated with catheters implanted in the same department during the same period, and that were managed with only systemic antibiotics were used as a control group. Antibiotic-lock solution consisted of a heparin solution of 20 IU/mL including vancomycin (for Gram-positive microorganisms) or ciprofloxacin or gentamicin (for Gram-negative bacilli), all at a concentration of 2 mg/mL. ALT was used for a minimum of 8-12 h/day, during 5-14 days. Effectiveness was assessed by clinical and microbiological criteria. Results: A total of 801 long-term intravascular devices were placed in 105 patients during this period. There were 127 episodes of bacteraemia documented in these patients, with 92 being CRB. Of these, 48 episodes fulfilled inclusion criteria for the analysis. Nineteen episodes were treated with ALT plus systemic antibiotics, and 29 episodes were treated only with systemic antibiotics. Isolated microorganisms were similar in the two groups. The catheter had to be removed during therapy in one episode in the antibiotic-lock group and in seven episodes in the control group. Relapse of the bacteraemia with the same microorganism after stopping therapy was observed in two and three patients in the study group and the control group, respectively. Overall, successful treatment was achieved in 84% and 65% of the episodes in the antibiotic-lock group and the control group, respectively (P = 0.27). Conclusions: ALT appears as an effective conservative treatment in the management of CRB associated with long-term intravascular devices (84% in the present series), especially in infections caused by coagulase-negative staphylococci.