_______________________________________________________________ Healthcare-Associated Infections
The nontunneled central venous catheter accounts for the majority of all intravascular device-related bloodstream infec- tions [30]. Peripheral catheters (arterial and venous) are rarely associated with bloodstream infections, and totally implantable catheters are associated with the lowest risk [30]. A systematic review of 200 prospective studies of intravascular device- related bloodstream infections indicated that the level of risk associated with various types of devices can vary substantially depending on whether risk is expressed as the number of infec- tions per 100 intravascular device-days or 1,000 intravascular device-days [246]. The risks associated with peripheral intrave- nous catheters were much higher when expressed over 1,000 intravascular device-days, pointing to the need for prevention strategies targeted to all types of devices [246]. Other risk factors are the length of time the catheter is in place and factors related to the patient’s health status (severity of illness, presence of burns or surgical wounds, compromised immune system, nutritional status) [30; 37]. Transmission and Common Pathogens Intravascular device-related bloodstream infections are trans- mitted by both endogenous and exogenous routes. The most common cause of infection related to short-term catheters is migration of skin organisms at the site of insertion, with the organisms traveling along the surface of the catheter and colonization at the catheter tip [30]. Direct contamination of the catheter or catheter hub by contact with hands or contami- nated fluids or devices is another cause [30]. Hematogenous seeding from another focus of infection is a less common cause, and contamination of infusion fluid is rare [30]. The most commonly reported pathogens for intravascular device-related bloodstream infections in 2018–2021 were coag- ulase-negative staphylococci (17%), Enterococcus spp. (12.5%), Candida albicans (12.1%), Candida spp. (8.6%), S. aureus (7.4%), E. faecium (7.2%), Candida glabrata (7%), Klebsiella spp. (4.7%), and E. coli (3%) [146]. The percentage of resistant S. aureus was 46% in 2018–2021 compared with 48% in 2015–2017 [146]. Prevention The CDC guidelines on the prevention of intravascular device- related bloodstream infections were published in 2002 and updated in 2011 and 2017 [30]. The most recent guidelines emphasize the following points [30]: • Using maximal sterile barrier precautions during central venous catheter insertion • Using a >0.5% chlorhexidine skin preparation with alcohol for antisepsis • Avoiding routine replacement of central venous catheters as a strategy to prevent infection • Using antiseptic/antibiotic impregnated short- term central venous catheters and chlorhexidine- impregnated sponge dressings if the rate of infection is not decreasing despite adherence to other strategies
• Educating and training healthcare providers who insert and maintain catheters The CDC guidelines define maximal sterile barrier precautions as the use of a cap, mask, sterile gloves, sterile gown, and a ster- ile full-body drape during insertion of an intravascular device (level IB) [30]. A sterile sleeve should also be used to protect pulmonary artery catheters during insertion (level IB) [30]. The CDC guidelines recommend use of an antiseptic of 70% alcohol, tincture of iodine, or chlorhexidine gluconate solution with alcohol before insertion of peripheral venous catheters (level IB) and a >0.5% chlorhexidine preparation with alcohol before insertion of central venous catheters or peripheral artery catheters and during dressing changes (category IA) [30]. The guidelines note that chlorhexidine preparations with alcohol have not been compared with povidone iodine in alcohol and thus no recommendation can be made in this regard [30]. In a meta-analysis of eight studies (4,143 catheters, primarily central line catheters), the chlorhexidine solution was found to reduce the risk for bloodstream infection by 49% [247]. In a subsequent study, use of this solution led to a 1.6% decrease in the rate of bloodstream infection, a 0.23% decrease in the incidence of death, and a cost savings of $113 per catheter used compared with povidone-iodine solutions [248]. Most intravascular device-related bloodstream infections develop at the site of insertion, due to the density of skin flora [30]. Rates of infection vary according to insertion site, with catheters in the internal jugular vein being associated with a greater risk of infection than catheters in the subclavian vein [30; 249; 250]. A 2005 study indicated that the site of insertion was not a risk factor for infection when experienced or trained healthcare workers inserted the catheters [251]. However, such experience will not always be the norm, and the subclavian vein has been recommended by the CDC as the preferred site when possible [30]. Another strategy to prevent infection has been the develop- ment of central venous catheters with antimicrobial coatings. These coatings have included a combination of chlorhexidine and silver sulfadiazine and a combination of minocycline and rifampin [252]. Both types of catheters are associated with a significantly lower rate of infection than that associated with standard catheters. When compared with each other, catheters impregnated with minocycline and rifampin were 12 times less likely to cause bloodstream infections than those coated with chlorhexidine and silver sulfadiazine [253]. The chlorhexidine- silver sulfadiazine coating has since been enhanced, and these second-generation catheters have significantly reduced bacterial colonization, with a trend toward fewer bloodstream infections [254; 255; 256]. Each coating adds to the cost of the catheter, and cost-effective analyses are necessary. On the basis of studies of intravascular device-related blood- stream infections, a bundle consisting of five preventive mea- sures has been recommended:
97
EliteLearning.com/Dental
Powered by FlippingBook