Reducing device-related BSIs aim of new guidelines

The Centers for Disease Control and Prevention has drafted revised infection control guidelines for intravascular devices that emphasize basic asepsis when inserting and maintaining lines, and set several timetables for safe changing of administration sets and catheter tubing.1

Intravascular devices addressed in the guidelines are those used to administer intravenous fluids, medications, blood products, and parenteral nutrition fluids, and to monitor the hemodynamic status of critically ill patients. The draft focuses largely on the epidemiology and preventive strategies for infections associated with the intravascular devices commonly used in health care, including peripheral venous and arterial catheters, central venous and arterial catheters, peripherally inserted central venous catheters, and pressure monitoring systems.

Most BSIs device-related

While considered indispensable in modern medical practice, intravascular devices are frequently complicated by a variety of local and systemic infections. Those include septic thrombophlebitis, endocarditis, bloodstream infections (BSIs), and infections resulting from hematogenous seeding of another body site by a colonized catheter.

The prime concern for preventive strategies is reducing the estimated 200,000 nosocomial BSIs that occur each year in U.S. hospitals. Most of the bloodstream infections are related to the use of an intravascular device, with rates substantially higher among patients with intravascular devices than among those without such devices, the CDC reports. From 1980 to 1989, significant increases were detected in the rates of nosocomial BSIs reported from the CDC National Nosocomial Infection Surveillance (NNIS) System. Reported rates increased by 70%-279%, depending on hospital size and affiliation, according to the guidelines, which are in the final stages of review and revision by the CDC Hospital Infection Control Practices Advisory Committee (HICPAC).

Potential sources for contamination and subsequent infection of intravascular devices include both the hands of health care workers and patient skin flora, making aseptic technique during placement and maintenance critical. (See figure, above.)

"Aseptic technique for insertion and maintenance encompasses everything -- cutaneous disinfection prior to inserting and use of gloves and hand washing when you are manipulating and handling [devices]," Rita McCormick, RN, HICPAC member and infection control practitioner at the University of Wisconsin Hospital and Clinics in Madison, tells Hospital Infection Control. "If we could get everybody to do all of those routinely, it would be of major assistance. It is failure to do what we already know that gets us into trouble."

Indeed, while the revised guidelines reflect a variety of updated practices from the 1983 CDC guidelines, many hospitals may have already made changes based on medical studies like those showing catheter administration sets could be safely changed at 72 hours and beyond.2-4

Much of the CDC recommendations are in line with current practice, McCormick says, noting, "I don't think that this will result in a whole lot of changes."

In that regard, the CDC draft recommendations for intravenous catheters and administration sets state that intravenous tubing should be changed no more frequently than every 72 hours unless clinically indicated. The draft guidelines state, however, that it remains "an unresolved issue" whether to go beyond 72 hours, and no recommendation is made to do so.

The CDC added an additional caveat for intravenous tubing used to administer blood or lipid emulsions, recommending such tubing be changed within 24 hours of completing infusion. Studies have indicated such fluids are more likely than other parenteral fluids to support microbial growth if contaminated, the CDC noted.5 (See infection control recommendations, p. 11.)

"There are things that have already been in place -- such as the recommendation for 72-hour changes on administration sets," says Michele L. Pearson, MD, epidemiologist in the CDC hospital infections program. "Many hospitals have gone to that practice based on studies that were in the literature. That is one of the more significant changes. Other things that may have substantial impact are our recommendations for changing of central venous catheters. We have now recommended that those not be routinely changed for infection control purposes."

Cost savings possible

In general, safely reducing changes of such equipment translates to cost savings for hospitals, and the CDC and HICPAC must balance risk vs. benefit in making such recommendations.

"We don't have a lot of data in the literature to allow us to fine-tune risk vs. benefit and cost," says acting HICPAC Chairman C. Glen Mayhall, MD, epidemiologist at the University of Texas Medical Center in Galveston. "We don't have cost data -- we don't have even good risk data for things other than infections. There are other types of risk that we have to balance against infection risks, like mechanical complications."

In that regard, the CDC encourages infection control practitioners to add to the database by doing institutional cost assessments and analysis of risk factors for both infections and noninfectious complications associated with intravascular devices, Pearson adds.

References

1. Centers for Disease Control and Prevention. Draft guideline for prevention of intravascular device-related infections. Fed Reg 60; [187]:49,978-50,006. (Sept. 27, 1995)

2. Snydman DR, Donnelly-Reidy M, Perry LK, et al. Intravenous tubing containing burettes can be safely changed at 72-hour intervals. Infect Control 1987; 8:113-116.

3. Josephson A, Gomber ME, Sierra MF, et al. The relationship between intravenous fluid contamination and the frequency of tubing replacement. Infect Control 1985; 6:367-370.

4. Maki DG, Botticelli JT, LeRoy ML, et al. Prospective study of replacing administration sets for intravenous therapy at 48- vs. 72-hour intervals: 72 hours is safe and cost effective. JAMA 1987; 258:1,777-1,781.

5. Crocker KS, Noga R, Filibeck DJ, et al. Microbial growth comparisons of five commercial parenteral lipid emulsions. J Parenter Enteral Nutr 1984; 8:391-395. *