Risk factors

Patients with co-morbid medical conditions are at greater risk of acquiring a CABSI. They frequently stay in the ICU and may require total parenteral nutrition, emergent insertion of a central line, and/or prolonged hospitalization.8 Adding to the complexity of CABSI are factors associated with the type of catheter.       

The vast majority of infections and serious complications are associated with CVCs, especially those placed in patients in the ICU.2 This occurs for several reasons: catheters are often placed in emergent situations when attention to aseptic technique is not optimal10,11; there is more manipulation of CVCs for infusion of blood products, drugs, and fluids and access for blood sampling; catheters remain in place for extended periods, which results in colonization of the catheter with microorganisms. Pulmonary artery catheters and peripheral arterial catheters are accessed numerous times a day for hemodynamic monitoring or to obtain laboratory specimens, thereby increasing the risk of contamination and subsequent infection.10,11      

The organisms mostly commonly associated with CABSI are Staphylococcus aureus, coagulase-negative staphylococci, and enterococci.2 Migration of microorganisms from the skin at the catheter insertion site to the catheter tip is the most common source of bloodstream infection for peripherally inserted, short-term catheters.2 Colonization of long-term catheters frequently occurs when the catheter hub becomes contaminated.2,10 Less common causes of CABSI include infection at another site leading to a hematogenously seeded catheter, and, rarely, contaminated infusate.