Prevention of infections caused by central venous catheters--established and novel measures.

Intravascular catheters play an important role in infections in intensive care and hemodialysis patients. This becomes evident only if full microbiological diagnoses are made. Difficulties in the diagnosis and treatment of microbially colonized catheters make the prevention of infection particularly important. The most important preventive measures are a strict evaluation of the indications for the use of the catheter and strict hygienic precautions during insertion and maintenance of the central venous catheter. Other measures, some of which are controversial, may be considered, such as the specific decontamination of Staphylococcus carriers using mupirocin. A new approach in the prevention of catheter-related infections is the use of catheter materials impregnated with antibiotics, antiseptics or metals. Slow-delivery systems release the antimicrobially active substance from the catheter material and thus reduce the proliferation of adherent bacteria. Some of these slow-delivery systems have been used in clinical trials, with varied results. Current research is directed towards the prevention of the first stage in the pathogenesis of catheter-associated infections, namely the adherence of bacteria to the catheter polymer, e.g. by impregnation of the polymer with silver. Laboratory studies, animal experiments and initial clinical trials suggest that it will soon be possible to reduce the frequency of catheter-associated infections to below the levels attainable with current general and specific preventive measures, through the use of coated catheters.