Hospital-acquired or nosocomial infections (defined as those not present or incubating at the time of admission to the hospital) and other health care–associated infections affect an estimated 1.7 million pts, cost $10–33 billion, and contribute up to 99,000 deaths in U.S. hospitals each year. Although efforts to lower infection risks are challenged by the growing numbers of immunocompromised pts, antibiotic-resistant bacteria, fungal and viral superinfections, and invasive procedures and devices, the “zero-tolerance” viewpoint of consumer advocates holds that nearly all health care–associated infections should be avoidable. Accordingly, federal legislation now exists to prevent U.S. hospitals from upgrading Medicare charges to pay hospital costs resulting from at least 14 specific nosocomial events.
PREVENTION OF HOSPITAL-ACQUIRED INFECTIONS
Nosocomial pathogens have reservoirs, are transmitted by largely predictable routes, and require susceptible hosts—features that allow the implementation of monitoring and prevention strategies.
Surveillance: Computerized algorithm-driven review of hospital databases is replacing manual review of microbiology laboratory results and surveys of nursing wards, but all these mechanisms keep track of infections acquired after hospital admission. Results of surveillance are expressed as rates and should include a denominator indicating the number of pts exposed to a specific risk (e.g., pts using a mechanical ventilator) or the number of intervention days (e.g., 1000 pt days on a ventilator).
Prevention and control measures: Hand hygiene is the single most important measure to prevent cross-infection.
– Health care workers’ rates of adherence to hand-hygiene recommendations are abysmally low at <50%.
– Other measures include identifying and eradicating reservoirs of infection and minimizing use of invasive procedures and catheters.
Isolation techniques: Isolation of infectious pts is a standard component of infection control programs.
– Standard precautions include hand hygiene and use of gloves when there is a potential for contact with blood, other body fluids, nonintact skin, or mucous membranes during the care of all pts. In certain cases, masks, eye protection, and gowns are used as well.
– Transmission-based guidelines: Airborne, droplet, and contact precautions—for which personnel don (at a minimum) N95 respirators, surgical face masks, and gowns and gloves, respectively—are used to prevent transmission of disease from pts with contagious clinical syndromes. More than one precaution can be used for diseases that have more than one mode of transmission (e.g., contact and airborne isolation for varicella).
NOSOCOMIAL AND DEVICE-RELATED INFECTIONS
Nosocomial infections are due to the presence of invasive devices in 25–50% of cases. Intensive education, “bundling” of evidence-based interventions, use of checklists to facilitate adherence, and improvements in the design of these devices have reduced infection rates. Table 81-1 summarizes effective interventions to reduce the incidence of the more common nosocomial infections.