Vascular Catheter-Related Infection and Sepsis

Abstract

Catheter-related sepsis is a clinical syndrome characterized by the presence of a catheter-associated infection along with a systemic inflammatory response. The continual increase in the use of central venous catheters (CVCs) has been associated with a substantial risk of infectious complications that prolong the hospital stay and increase costs. The literature on CVCs was reviewed to determine the incidence of catheterrelated sepsis, its diagnosis, and the role of biofilms in pathogenesis. The European Sepsis Group recently reported that 28% of CVC infections in intensive care unit patients were associated with sepsis, 24% with severe sepsis, and 30% with septic shock. Clinical diagnosis remains difficult. After CVC insertion, the intravascular portion of the device is covered rapidly by a thrombin layer, rich in host-derived proteins, that forms a conditioning film and promotes surface adherence of microbial colonizers. These microorganisms then enter their sessile mode of growth, secreting an exopolysaccharide slime within which organism density is regulated by quorum-sensing molecules. Microorganisms are dispersed in clumps that can become septic emboli. Antiadhesive, antiseptic, and antibiotic coatings of catheters have demonstrated only modest clinical efficacy. Our group is involved in the design and in vitro assessment of new polymeric matrices for controlled release of antimicrobial molecules, and in comparative clinical studies of conventional versus antibiotic-coated or -impregnated catheters.