Nosocomial pneumonia defined

For the numerator of a nosocomial pneumonia rate, accurate and consistent case finding of nosocomial pneumonia in the population under study is needed. Consistent definitions for case finding are essential. Therefore, it is imperative that there be available a uniform set of criteria that define nosocomial pneumonia. The most widely used definitions currently in use are the definitions used by National Nosocomial Infection Surveillance (NNIS) system hospitals, the complete version of which was published in Hospital Epidemiology and Infection Control in 1996. The current definition for nosocomial pneumonia is shown on Table 1. 

Prevalence is the total number of active (existing and new) cases of the disease in a defined population, either during a specified period (period prevalence) or at a specified point in time (point prevalence). The prevalence nosocomial infection rate is calculated simply by dividing the number of active nosocomial infections in patients surveyed by the number of patients surveyed. Because nosocomial pneumonias occur relatively infrequently, the period chosen for surveillance must be large enough for an adequate estimation of a hospital s prevalence rate and usually varies depending on the number of occupied beds in a hospital. In addition, these rates require risk adjustment, which is currently not available for interhospital comparison of prevalence rates. 

Nosocomial pneumonia (NP) is defined as an infection of lung parenchyma that was neither present nor incubating at the time of hospital admission. As the second most frequent hospital-acquired infection in the United States, NP accounts for approximately 15% of aU hospital-associated infections (1,2). Despite improvements in diagnosis and treatment, the associated mortality and morbidity rates remain high and related costs have been estimated to be about 1.2 bilUon per year (3). 

A variety of clinical quality indicators may be used to evaluate the efficacy of efforts to prevent nosocomial pneumonia. A clinical indicator may be defined as a quantitative measure that can be used as a guide to monitor and evaluate the quality of important patient care and support service activities ... 

Table 2 Criteria Used by the National Nosocomial Infections Surveillance System to Define Nosocomial Pneumonia...

Because of the difficulty in accurately establishing the diagnosis of a hospital-acquired pneumonia or tracheitis in a critically ill child, a standardized approach for defining these infections offers the best opportunity for interhospital comparisons. The Centers for Disease Control and Prevention (CDC) definitions for lower respiratory tract infections in children are included in Tables 2 and 3 (27). However, pneumonia and tracheitis may still be diagnosed and treated in children who do not satisfy these criteria. Also, children who fulfill these criteria may not truly have a nosocomial LRI. This occurs most commonly when the child exhibits a deterioration in his or her underlying pulmonary condition. 

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