Central venous catheters (CVCs) are life-saving vascular access ports in patients requiring long-term intravenous therapy. CVCs are used to administer fluids, blood products, nutritional solutions, medication, and for hemodynamic monitoring.
While CVCs are important in treating many conditions, particularly in intensive care units, they pose a significant risk of device-related infections and are leading cause of morbidity and mortality. Of the approximately 7 million CVCs used annually in the U.S., about 500,000 or 7% become infected leading to serious, life threatening infections called catheter-related blood stream infections (CRBSIs).
CRBSI is a clinical term used to categorize patients with an intravascular catheter who have:
- A bacterial or fungal infection, with at least one positive blood culture obtained from a peripheral vein;
- Clinical manifestations of infection including fever, chills, and/or low blood pressure; and
- No apparent source for the bloodstream infection other than the catheter.
The incidence of CRBSI varies by type of catheter, the frequency of catheter manipulation, and the patient’s underlying disease and severity of illness.
A Central Venous Catheter
CRBSIs and Biofilm Formation
Colonization of a CVC, by microbes on a patient’s skin and from other external sources, occurs rapidly following device insertion. Biofilm may form when bacteria adhere to surfaces in moist environments by excreting a matrix of glue-like substances. A biofilm community can be formed by a single bacterial species, but more commonly consists of many species of bacteria and other microorganisms.
When a biofilm forms on a catheter surface, it may put patients at a higher risk of developing recurrent CRBSIs and it may also make CRBSIs more resistant to conventional treatment.
The standard of care in the management of CRBSIs consists of removing the infected CVC and replacing it with a new catheter at a different vascular access site. These procedures are costly and 15% to 20% of the procedures are associated with significant morbidity. There are currently no approved therapies to salvage infected CVCs.
Complications in Cancer and Hemodialysis Patients
In cancer and hemodialysis patients with long-term surgically implantable silicone catheters, removal of the CVC and reinsertion of a new one at a different site may be difficult, or even impossible, because of the unavailability of other accessible vascular sites and the need to maintain infusion therapy.
Complications in Patients with Underlying Coagulopathy
Critically ill patients with short-term catheters often have underlying coagulopathy, where the blood’s ability to clot is impaired. This condition would make reinsertion of a new CVC at a different site risky in terms of mechanical complications, such as hemopneumothorax, misplacement, or arterial puncture.