Use of antibiotic locks to treat colonized central venous catheters

Infections that result from bacterial colonization of central venous catheters are a significant problem in modern healthcare. The most effective means of eradication of such infections is the removal of colonized lines, but line removal carries drawbacks of its own and in many cases the balance of risks favours treatment in situ. Systemic antibiotics are usually administered but these frequently fall to achieve sterilization, and accordingly attention has turned to intraluminal therapy using antibiotic locks, in which 1-2 mL of a concentrated antibiotic solution is instilled to fill the lumen, left for a predetermined period, and removed. The evidence in favour of this technique is anecdotal and should not be allowed to influence any decision about line removal, but is sufficiently encouraging to justify the use of locks when in situ treatment is deemed acceptable. Indications, agents and appropriate administration regimes are discussed.