ABSTRACT
Nosocomial respiratory infections are a substantial healthcare problem and contribute to increased morbidity and mortality among hospitalized patients. Not only that, this type of infection also substantially stresses the hospital budget. In the retrospective study investigating a large US inpatient database, Rello and associates reported a figure as high as $40 000 for excess mean hospital charges1
when ventilator-associated pneumonia (VAP) occurred. Physicians are tempted to establish a causal relationship between their work and the occurrence of a nosocomial infection. In fact the liability of the physicians is increasing, but it has to be clearly stated that a hospital without increased risk for infection is desirable but will also not exist in the near future. It is therefore inevitable that the treating physicians understand that nosocomial infections have to be accepted and their work will have to be dedicated towards the goals of minimizing and controlling the circumstances that facilitate these infections. It has been shown more than once that nosocomial pneumonia is the second most frequent nosocomial infection after urinary tract and before primary bloodstream infections.2-4
However, the absolute numbers vary largely owing to problems and differences with the definition of nosocomial infections. Moreover, the incidence of nosocomial respiratory infections varies largely between countries, and types of ICUs (e.g. medical versus surgical) and epidemiologic data derived from a national or even multinational survey may be of limited value to the physician in charge. To be able to deliver meaningful information to each individual physician, this chapter will therefore not only focus on figures regarding the incidence but will also discuss
Several concepts for the diagnosis of nosocomial pneumonia exist but only few have been validated in human postmortem studies or histology.5, 6 Among the nosocomial respiratory infections, the definitions for nosocomial or hospital-acquired pneumonia cover the largest range. Nosocomial pneumonia is defined as pneumonia that occurs 48 hours or more after hospital admission, which was not incubating at the time of admission.7 The diagnosis of nosocomial pneumonia does not require intubation nor mechanical ventilation and may therefore be cared for in a hospital ward or in the intensive care unit (ICU). VAP, however, refers to pneumonia that arises >48-72 hours after endotracheal intubation, with no clinical evidence suggesting the presence or likely development of pneumonia at the time of intubation.8, 9 Owing to the increasing number of patients who are cared for in day-care facilities and nursing homes, a third definition has been forwarded by the American Thoracic Society and includes any patient who was hospitalized in an acute care hospital for ≥2 days within 90 days of the infection; resided in a nursing home or long-term care facility; received recent intravenous antibiotic therapy, chemotherapy, or wound care within the past 30 days of the current infection; or attended a hospital or hemodialysis clinic.7, 10, 11 The diagnosis of these entities is based on epidemiologic and clinical grounds in the presence of a pulmonary infiltrate suggestive of lung infection in the chest radiograph. Recently another potentially important clinical entity has moved into the focus of
many of the clinical signs of nosocomial pneumonia in the absence of radiographically visible pulmonary infiltrations (Table 38.1). The following paragraphs will discuss these entities in more depth.
