Snaterse, M., Rüger, W., & Lucas, C. (2010). Antibiotic-based catheter lock solutions for prevention of catheter-related bloodstream infection: A systematic review of randomised controlled trials. Journal of Hospital Infection, 75, 1–11.

The purpose of the article was to summarize the evidence on the effectiveness of antibiotic-based catheter-lock solutions as compared to heparin-lock solutions to prevent catheter-related blood stream infections (CRBSI) in all patients with long-term intermittent use of central venous catheters (CVCs).

Medline and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched.

Trials that were included were planned as randomized, controlled trials, quasi-randomized trials or systematic reviews/meta-analyses of randomized or quasi-randomized trials, or published as an article. Trials were also included if the effects of one or more preventative antibiotic-based lock solutions were studied in patients with CVCs for intermittent use, and the presentation of sufficient data for calculating risks of CRBSI in the treatment and control group was examined.

No exclusion criteria were specified.
 

Twenty-three total references were retrieved.

Two reviewers independently assessed trial quality using the following components: concealment of allocation, blinding during treatment and at outcome assessment, description of drop-outs, and analysis. Only trial data related to the topic of the review were considered.

The included trials were flawed due to shortcomings that could have introduced bias, as only 2 of 16 trails clearly prevent performance bias and, in eight of those trials, methods of blinding were unclear. Nine  trials had unclear allocation concealment and only one trial performed analysis by intention to treat. Baseline comparability of groups did not differ. Design and methodology of included studies were sufficient to analyze and pool data.
 

• Sixteen studies were included in the final review.
• 1,383 catheter days were included from 532 patients with cancer (261 were children).
• Catheter days across all included studies ranged from 14–80.
• Key sample characteristics were not specified.

• The phase of care was active treatment
• Applications were for late effects, survivorship, and pediatrics

Overall, it could not be determined which antibiotic-based lock solution is most effective in reducing CRBSI. Only two small trials compared different antibiotics head-to-head. In hemodialysis patients, there was a significant benefit in favor of the antibiotic-based solutions in patients with cuffed or tunneled catheters.  In pediatric oncology patients, there was a small but statistically significant benefit of the antibiotic-based lock solutions in the prevention of BSI (not CRBSI). There was an overlap of 42 elderly patients between two trials. Vancomycin-containing lock or flush solutions are effective in reducing the risk of BSI in patients with cancer. One trial also demonstrated a significant reduction of gram-positive CRBSI, using vancomycin flush solutions in pediatric patients with cancer. 

• The studies should be interpreted with caution as all had a small number of patients.
• There was a difference in solutions that were flushed into the bloodstream and lock solutions, and these were not differentiated in this review.  

Although some results seemed promising, these should be interpreted with care, especially in patients with cancer. There was no differentiation made between BSI and CRBSI, which could be complicated in interpreting the results. There also is a small sampling in regard to patients with cancer, as there were only six oncology trials included in the review. There are no real indications that the use of antibiotic-based lock solutions could prevent catheter-related infections, and it is not possible to determine which antibiotic-based lock solution is most effective. There is the risk of bacterial antibiotic resistance when using broad spectrum antibiotics for locking solutions. This should be weighed against the benefit of locking or flushing solutions.