Intravascular catheter-related infections: a preventable challenge in the critically ill

In modem medicine, central venous catheters (CVCs) have a pivotal role in the management of critically ill patients. The most serious complication of effective CVC placement is catheter-related bloodstream infection (CRBSI). Microbial colonization and CRBSI are the byproducts of the interaction of 4 factors: (1) microbial factors (hydrophobicity and exopolysaccharide production), (2) host factors (such protein adhesins as fibrin and fibronectin that attach to the catheter surface), (3) catheter material (hydrophobicity, surface charges, thrombogenicity), and (4) iatrogenic factors (total parenteral nutrition, interleukin-2). The organisms most frequently associated with CRBSI are Staphylococcus epidermidis, Staphylococcus aureus, and Candida spp. CRBSIs were traditionally diagnosed through semiquantitative or quantitative cultures of the catheter tip. However, the diagnosis can be achieved without catheter removal through cultures of blood specimens collected simultaneously though the CVC and a peripheral vein. Currently, the most effective method of preventing a CRBSI is the use of a CVC coated with antimicrobial agents. Intravenous administration of vancomycin for 7 days is adequate for an uncomplicated CRBSI caused by coagulase-negative staphylococci, and at least 10 days of therapy with beta-lactams is required for an uncomplicated infection caused by methicillin-sensitive S. aureus. CRBSI caused by Candida albicans or Candida parapsilosis can be treated with at least 14 days of therapy with fluconazole or amphotericin B. In the case of Candida krusei, only amphotericin B is effective.