The pathogenesis and prevention of central venous catheter-related infections.

Vascular catheters are a major source of nosocomial infections. Definite diagnosis of catheter-related infections should include the use of quantitative catheter cultures or differential quantitative blood cultures. The skin and catheter hub are the two major sources for the introduction of the colonizing organisms. Both microbial (slime) and host (fibrin and fibrinectin) factors contribute to the formation of the biofilm which is essential for the adherence and maintenance of the colonization. Staphylococci and Candida are the leading causative agents. Prolonged duration of catheterization, thrombogenic catheter material, frequent manipulation of the catheter, improper aseptic insertion and maintenance techniques, tranparent plastic dressings, contaminated skin solutions, location of the catheter, and possibly multilumen central venous catheters (CVC) are risk factors predisposing to infections. Preventive measures include a skilled infusion therapy team, topical disinfectants such as chlorhexidine and topical antibiotics, silver impregnated cuffs (for short term CVC), coating catheters with antiseptic agents and maximal barrier precautions during insertion. Exchanging central venous catheters over a guidewire might be useful diagnostically but have not been proven to be of any therapeutic or preventive potential.