Saturday, February 7, 2009

Antibiotic Lock Solutions for Catheter-Related Bacteremia

It doesn't take long for the renal fellow to realize that a huge chunk of ESRD hospital admissions are due to catheter-related bacteremia, and a number of different algorithms exist for the management of dialysis catheter-related infections. Typically, this involves removal or exchange of the catheter in association with iv antibiotics targeting gram-positive (and sometimes gram-negative) organisms. More recently, another strategy has been suggested for the management of catheter-related bacteremia: antibiotic lock solutions. What is their current role?

The antibiotic lock method--which remains controversial and is specifically not recommended in the "Up To Date" section on "Management of infected cuffed central venous catheters used for hemodialysis"--involves the installation of an antibiotic solution into the hub of the catheter and allowing it to dwell for a particular length of time. This could conceivably be used either for treatment of existing bacteremia or for the prevention of bacteremia as a prophylactic.

Most of the existing evidence look at the use of antibiotic lock solution as a preventative measure. A 2008 meta-analysis of 7 studies (which combined measured >800 catheters) looking at a variety of different antibiotic lock solutions demonstrated a greater than 7-fold less likely risk of developing catheter-related bacteremia, suggesting that the practice is sound. However, there are still concerns regarding (a) the emergence of antibiotic resistance as a result of broad acceptance of this practice, (b) whether or not the prolonged use of antibiotics could conceivably result in toxicities to the patient due to some degree of systemic absorption, and (c) exactly how such a treatment would be paid for.

There is much less data on the use of antibiotic lock solution as treatment of existing bacteremia, and much of it is on non-dialysis catheters. I can't think of anybody that would recommend using antibiotic lock solution by itself as a treatment regimen for catheter-related bacteremia; it would have to be in addition to systemic antibiotics. A good review of the literature can be found here.

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