Page 54 - Hall et al (2015) Principles of Critical Care-McGraw-Hill

CHAPTER 4: Infection Prevention and Surveillance in the Intensive Care Unit 23

CHAPTER Infection Prevention and better understand the impact of infection control programs on health
care–associated infection rates in a random sample of 338 US hospi-
4 Surveillance in the Intensive tals. Programs that had the greatest impact in reducing health care–
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associated infection rates had the following components: organized
Care Unit surveillance and active intervention in patient care by infection control
staff to reduce the risk of infection, a physician trained in infection con-
Hitoshi Honda trol methods, a fixed ratio of infection control specialists to patient beds,
David K. Warren and a system for reporting surgical infection rate to surgeons. In hospi-
Marin H. Kollef tals that implemented infection control programs meeting these criteria,
the incidence of health care–associated infections decreased hospital
wide by 32%, whereas in hospitals with ineffectual programs, infections
KEY POINTS increased by 18% over a 5-year period. These findings led to regulations
requiring that hospitals demonstrate that their infection prevention
• Focused surveillance for health care–associated infections is the programs meet the preceding criteria in order to maintain accreditation.
cornerstone of infection prevention activities in the ICU.
• Commonly used invasive devices such as central venous and uri-
nary catheters and endotracheal tubes are significant risk factors SURVEILLANCE
for health care–associated infection. Evidence-based ICU policies Surveillance for health care–associated infection is the cornerstone
and procedures and staff education can reduce the risk of device- of effective infection control activity in the ICU. Surveillance activity
related infections. serves several key functions, including the early detection of potential
• Antibiotic resistance is an increasing problem, and its containment outbreaks, the identification of high endemic rates of infection as targets
and prevention require a multifactorial approach, including ade- for intervention, and evaluation of the effectiveness of efforts to prevent
quate hand hygiene, surveillance for resistant pathogens, enforced infection. The process of surveillance itself involves the continuous and
infection control precautions, and prudent use of antibiotics. systematic collection, tabulation, analysis, and dissemination of infor-
• Standard infection control precautions should be applied to all mation on the occurrence of nosocomial infections within the ICU. It
ICU patients. Precautions for contagious or epidemiologically was noted early in the development of infection control programs that
significant pathogens are based on modes of transmission. feedback of nosocomial infection rates to clinicians, along with active
intervention, is a necessary element to a successful program and that
collection of surveillance information without this feedback is ineffec-
tual at reducing infection rates. Health care–associated infection sur-
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Health care–associated infections result in significant morbidity and veillance in the ICU involves the cooperation of both infection control
mortality. Health care–associated infections have been reported to and ICU personnel for both exchange of data and developing effective
affect approximately 2 million hospitalized patients in the United States infection control measures.
annually, at an estimated cost of $57.6 billion in 2000 and approximately Infection control surveillance, particularly when it involves chart
100,000 deaths. ICU beds, while only accounting for 5% to 10% of all review, can be labor intensive. Because of the reality that limited
1-3
hospital beds, are responsible for 10% to 25% of health care costs gener- resources are available for infection control surveillance and interven-
ated. Patients admitted to the ICU have been shown to be at particular tion, a practice known as focused or targeted surveillance is commonly
4
risk for health care–associated infections, with a prevalence as high as employed. This involves both hospital infection control and ICU per-
30%. Given the increasing strain on health care resources in the United sonnel making determinations of the particular health care–associated
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States and other countries, and the personal impact that these infections infections to be monitored routinely. The factors involved in making the
have on patients, the prevention of nosocomial infections in the ICU decision include the degree of morbidity or mortality that results from
should be an important goal of any critical care clinician. the infection, the frequency that the infection is known or perceived to
A likely explanation to account for the observation that ICU patients occur in the ICU, the proportion of ICU patients at risk of becoming
are more vulnerable to acquiring a health care–associated infection infected, the extent to which effective interventions can be implemented
compared with other hospitalized patients is that critically ill patients by the ICU team, the perception by both infection control and ICU
frequently require invasive medical devices, such as urinary catheters, personnel that a particular infection represents a significant problem for
central venous and arterial catheters, and endotracheal tubes. Data on that unit, and finally, state public-reporting mandates.
a sample of ICUs from the Centers for Disease Control and Prevention Infection prevention surveillance data in the ICU typically are
(CDC) show that adult ICU patients have central venous catheters in reported as the occurrence of a particular infection over a defined time
place and receive mechanical ventilation an average of 53% and 42% period at risk (eg, cases of ventilator-associated pneumonia per total
of their total time spent in the ICU, respectively. These devices result number of patient days spent on mechanical ventilation per month),
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in infection by compromising the normal skin and mucosal barriers also known as an incidence density. For infections that result from a
and serving as a nidus for the development of biofilms, which provide point exposure (eg, the number of tracheostomy site infections per
a protected environment for bacteria and fungi. In a survey of cases of total number of tracheotomies performed in one quarter), a cumulative
ICU-acquired primary bacteremia, 47% were catheter related. While incidence can be determined. Cumulative incidence is reported less com-
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the increased severity of illness of ICU patients makes intuitive sense as monly in the ICU owing to the observation that infections in the ICU
a potential risk factor for health care–associated infection, few studies result primarily from invasive devices that are in place for days to weeks.
have shown a consistent relationship. This may be explained, however, In order for the information collected for infection surveillance to
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by the fact that scoring systems were developed primarily to predict be interpretable, a case definition for infection has to be developed.
mortality and may not adequately capture markers for health care– Criteria for the diagnosis of health care–associated infections have been
associated infection, such as the need for prolonged parenteral nutrition. developed by the CDC. These surveillance definitions are widely used
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Infection control in the ICU arose from hospital-wide infection for tracking infection incidence within ICUs. It is important to note that
control programs developed in response to the staphylococcal pan- these definitions were developed to ensure standardized surveillance
demic of the late 1950s and early 1960s. In 1976, the CDC initiated methods. Many states in the United States that mandate public reporting
the Study on the Efficacy of Nosocomial Infection Control (SENIC) to of health care–associated infections require these definitions be used.

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