Antibiotic Lock Technique: Review of the Literature

Megan B. Bestul, PharmD; Heather L. VandenBussche, PharmD


Pharmacotherapy. 2005;25(2):211-227. 

In This Article

Abstract and Introduction

Central venous catheters (CVCs) are frequently used for patients requiring long-term venous access. Catheter-related infection is a serious complication associated with extended use of a CVC and can result in catheter removal. The antibiotic lock technique, a controversial method for sterilizing the catheter lumen, involves instilling high concentrations of antibiotics with or without heparin into the catheter lumen for extended periods of time. Studies differ regarding the choice and concentrations of antibiotics, dwell times in the catheter lumen, presence of heparin in the antibiotic lock technique solution, use of systemic antibiotics with the technique, and use of the technique for prevention or treatment of catheter-related infections. Results of in vitro studies demonstrate that many antibiotic combinations are stable and maintain high drug concentrations for prolonged periods of time. In vivo studies report the success of multiple combinations for both prevention and treatment with antibiotic lock technique in salvaging these catheters.

Central venous catheters (CVCs) have become an integral part of medical management for a variety of patients, including those requiring long-term total parenteral nutrition, chemotherapy, or hemodialysis. Infection of the catheter or catheter hub and catheter-related septicemia are major complications for patients with permanent or semipermanent indwelling catheters. For many patients, venous access is limited, and continuous removal and replacement of catheters is usually not feasible when these devices become infected. Systemic and/or local antibiotic therapy is often used to prevent catheter removal in these patients who rely on indwelling devices for long-term medical management.

Despite efforts to improve and use proper aseptic techniques, 1 of every 20 CVCs inserted results in at least one systemic infection.[1] These infections are associated with up to 25% mortality, an estimated cost of $28,690 for each episode of catheter-related sepsis, and an average increase of 6.5 days in hospitalization for critically ill patients.[2] The number of catheter-related bacteremia cases is estimated to be more than 35,000/year.[3] With this number rising annually due to the increased use of CVCs for long-term medical management, a variety of methods have been developed to prevent and treat CVC infections and avoid catheter removal.

The antibiotic lock technique is a controversial method used to prevent and treat catheter-related infections. This technique involves instilling an antibiotic solution into the catheter hub and allowing the solution to dwell for a particular length of time, with the goal of eradicating organisms from an infected line or preventing a line from becoming colonized and at risk for infection. The concepts behind antibiotic lock technique are to prolong the life of the catheter while reducing morbidity and costs of managing catheter-related infections. In addition, the use of antibiotic lock technique may spare patients from certain toxic effects of systemic antibiotic administration, and the risk of bacterial resistance may be reduced.[3,4]

Studies that evaluated antibiotic lock technique vary in the types of antibiotics and concentrations used, the addition of heparin to the solutions, dwell times in the catheter lumen, and use of the technique for prevention or treatment of CVC infection. Making evidence-based decisions regarding antibiotic lock technique recommen-dations is difficult for health care professionals because of differences in study methods and outcomes measured in small observational studies, as well as lack of large randomized clinical trials to assess effectiveness.

Information on antibiotic lock technique was obtained through a literature search of the PubMed database from January 1972-January 2004 and a manual review of reference lists from identified studies.