Interview with
Jeffrey H. Burbank
Founder& CEO of NxStage

Hemodialysis.com: What are the main findings of the study?

We looked at our data by breaking the timeline into three separate periods; no antibiotic lock (ABL) use, ABL use as needed and ABL use per protocol in the unit.

By looking at our 10 years retrospective data, we were able to demonstrate that the use of antibiotic locks (mainly tobramycin-tissue plasminogen activator (TPA) locks) as protocol in our unit, there was a significant decrease in total systemic antibiotic exposure and the percentage of catheters lost to malfunction.

This was achieved with similar CRB prevalence between the three ERAs and there was no noted increase in the infection-related complications.

Therefore, addendum of ABL to systemic antibiotics for treatment and using them for prevention in the high risk population offered similar CRB treatment success rates with less exposure to cumulative dose of systemic antibiotics.

Hemodialysis.com: Were any of the findings unexpected?

The changes in the antimicrobial resistance patterns were somewhat surprise to us. During daily practice, we did not recognize that there might be a change in the antimicrobial resistance patterns.

Our main ABL was tobramycin-TPA and over the decade, with the more frequent use of the ABL, there was a trend to increased tobramycin-gentamicin resistance for gram positive infections, but no recognizable change for gram negative and polymicrobial infections. This finding was not easy to explain. This might be a problem in long-term follow-ups. There were no noticeable trends for other antimicrobials.

Similar findings were recently reported by others investigators as well.

1. Abbas SA, et al. AJKD 2009; 53: 492-502

2. Jones SM, et al. AJKD 2011; 57:449-455

Hemodialysis.com: What should clinicians and patients take away from your report? 

Our colleagues should realize that ABL can not only be used for prevention of CRB but also for the treatment of already diagnosed CRB.

The intraluminal biofilm formation is inevitable for long-term catheters and systemic antimicrobials do not reach to enough concentrations in the vicinity to have an effect on the biofilm.

With the use of ABL, we may be able to decrease the systemic antimicrobial exposures of our patients while treating the infections just as successfully and may be able to prolong the survival of the catheters, both of which are very important for patients using long-term catheters.

Hemodialysis.com : What recommendations do you have for future research as a result of this study?  

As the nephrology community, we still have to conduct the big numbered randomized controlled trials to see the effectiveness of the use of ABL for the tre

atment and the prophylaxis of CRB. The end-points should include overall catheter survival and patient survival and not only time to first CRB because long-term beneficial OR detrimental effects of ABL need to be demonstrated.

We have to spend more time and publications in understanding the biofilms, both the natural outcome and the effect ABL have on the biofilms.

Whether we like them or hate them, long-term catheters are a fact of life and act as a life-line for these patients. No matter how much we push for AV fistulas and AV grafts, we have to recognize that in the best circumstances 1/3 to ¼ of all our patients have to be dialysed through a catheter. This adds up to 75,000 to 80,000 patients just in United States.

Infections and thrombosis may not need to be a natural history of long-term catheters in these patients.

Reference:

Onder, A. M., Billings, A. A., Chandar, J., Nield, L., Francoeur, D., Simon, N., Abitbol, C. and Zilleruelo, G. (2012), Antibiotic lock solutions allow less systemic antibiotic exposure and less catheter malfunction without adversely affecting antimicrobial resistance patterns. Hemodialysis International. doi: 10.1111/j.1542-4758.2012.00717.x