ABSTRACT
Demographics and Epidemiology of Catheter-Related Infections Intravascular (IV) catheters are a mandatory adjunct to patient care in the intensive care unit (ICU) setting. The median rate of central line-associated bloodstream infections (BSI) ranges from 1.8 to 5.2 per 1,000 catheter-days in ICUs.(1, 2) The data imply that 80,000 central venous catheter-associated BSIs occur annually in United States (U.S.) ICUs.(3)
What Is the Morbidity, Mortality, and Cost of Catheter-Related BSI? The attributable mortality from nosocomial BSI is high in critically ill patients (4), although, upon adjusting for preinfection severity of illness, this association may be lost.(5) Nonetheless, the high morbidity, the increased length of stay (LOS) within the ICU and hospital, and the associated increased costs are not in doubt, although there is some difficulty in deriving these numbers. Nosocomial BSIs result in a 5-day excess stay within ICUs and result in at least $16,000 of excess costs per episode.(6) When they occur in critically ill ICU patients, catheter-related (CR)BSIs are associated with an increase of $71,000 in ICU cost and a 20-day increase in ICU LOS.(7) The annual cost of caring for patients with central venous catheter (CVC)-associated BSIs may approximate half a billion dollars annually.(8)
Catheter Colonization: How Is This Term Defined? What’s the Treatment? As defined by the Center for Disease Control (CDC), catheter colonization is diagnosed if a positive culture of a catheter segment (15 or greater colony-forming units [cfu] if by semiquantitative culture or 1,000 or greater cfu if by quantitative culture) without clinical evidence of infection.(9) The semiquantitative technique, as described by Maki et al. (10), involves rolling a catheter segment back and forth across the surface of a blood-agar plate. It distinguishes infection (greater than 15 colonies) from low-density colonization or contamination. The quantitative technique involves placing the catheter segment in broth and sonicating it for 1 minute.(11) The broth is then vortexed, diluted, and surface-plated on soy agar. This method displaces intraluminal pathogens and increases the number of organisms that can be quantitated, as compared with the semiquantitative technique.(11) Treatment of catheter colonization is catheter removal; antibiotics are generally not indicated unless the diagnosis of a BSI cannot be ruled out (e.g., if blood cultures were not drawn).
