Intravenous catheter-related infections

Vascular catheter-related infection is an important cause of mortality and morbidity in hospitalized patients. The mean incidence of catheter-related bloodstream infection in hospitalized pediatric patients is 2.4 episodes per 1,000 days. Totally implantable central venous catheters may be associated with a lower risk of infection. Coagulase-negative staphylococci are the predominant cause and account for about one third of episodes of catheter-related bloodstream infection. The diagnosis of catheter-related bloodstream infection is often difficult because there are frequently no signs of inflammation around the catheter. Diagnosis depends on either a positive quantitative catheter culture yielding the same microorganism recovered from the bloodstream or differential quantitative blood cultures with significantly greater colony counts from blood drawn through the catheter than from blood drawn through a peripheral vein. Alternatively, probably catheter-related sepsis can be diagnosed when clinical sepsis is refractory to antimicrobial therapy but responds to catheter removal. Often these criteria are not met but catheter-related bloodstream infection is presumed because a common skin microorganism is isolated from the blood when clinical manifestations of bloodstream infection are present and there is no other apparent source of infection. Microorganisms causing catheter-related bloodstream infection gain access to the bloodstream predominantly from either the catheter insertion site or the catheter hub. Most catheter-related infections occurring shortly after catheter insertion probably gain access to the bloodstream by extraluminal migration along the catheter from the skin at the catheter insertion site. When catheters are in place for extended periods, especially greater than 30 days, the catheter hub probably plays a major role in microorganisms gaining access and then migrating endoluminally until reaching the bloodstream. Recently employed strategies for the prevention of catheter-related infections include topical antibiotics or antiseptics at the catheter insertion site, flush solutions containing vancomycin, and bonding antimicrobial agents to the catheter. Infection of peripheral and central venous catheters generally resolves after catheter removal. For tunneled silicone catheters, most episodes of catheter-related infection can be initially managed with antimicrobial therapy infused through the catheter without catheter removal. Staphylococcus aureus is generally more aggressive and associated with more complications than coagulase-negative staphylococci. Microorganisms that usually require catheter removal include Candida and Bacillus species. Adjunctive treatments of catheter infections include the use of urokinase. Catheter-related infection remains an important complication of vascular access. Novel prevention and treatment strategies are currently being investigated. In the near future bonding of antibiotics or other agents to catheters may become routine.(ABSTRACT TRUNCATED AT 400 WORDS)