Pathogenesis and prevention of catheter-related septicemia.

Intravascular catheters are contaminated by bacterial flora present on the patient's own skin or on the hands of the personnel manipulating the catheter-tubing junction. In the former case, contamination is more often extraluminal and often leads to CRS soon after catheter insertion. In the second circumstance, contamination preferentially involves the endoluminal route and results in bacteremia after the initial 10 to 14 days of catheter use. Effective prevention relies on thorough aseptic technique during insertion of the catheter or manipulation of its hub. Further studies are required to define the best means of achieving permanent sterilization of the insertion site. New hub designs should reduce the risk of hub contamination and CRS in prolonged intravascular catheterizations.

Prevention of catheter sepsis: the hub.

The prevention of catheter sepsis lies in a sound understanding of the routes through which catheters get contaminated. The catheter hub has been recognized as a portal for microorganisms causing catheter sepsis, particularly in central venous catheters inserted for > 1 wk. Bacteria and fungi may reach the internal surface of the catheter connector during manipulation by hospital staff and then colonize the entire lumen of the catheter. Endoluminal contamination has diagnostic, therapeutic, and preventive implications. Some traditional preventive approaches (site care, subcutaneous cuffs and tunnels, maximal aseptic barriers at the time of catheter insertion, and external antiseptic or antibiotic coating) may fail because they focus solely on the skin as a source of bacteria. Hub-related catheter sepsis can be prevented by aseptic hub manipulation, appropriate junction protection, and by reducing the number of catheter lumens, side ports, three-way stopcocks, and changes of the infusion sets. Needleless systems must be evaluated in terms of their safety in preventing endoluminal contamination. A new disinfecting catheter hub incorporating an antiseptic barrier has been developed and reduced hub-related catheter sepsis by more than 90%. The endoluminal route of intravascular catheter contamination must be taken into account when designing strategies for the diagnosis and prevention of catheter-related sepsis.