ABSTRACT
Nosocomial or hospital-acquired pneumonias are infections of the lung parenchyma occurring more than 48 h after hospital admission and excluding infections incubating at the time of admission1. Environmental sources (air, water, food, fomites), medical devices (endotracheal tubes, suction catheters, bronchoscopes, respiratory therapy equipment), other patients, and hospital staff can serve as vectors for nosocomial infection2. Pneumonia is the most common nosocomial infection in the ICU and the second most common hospital-acquired infection. Occurrence ranges from 0.4% in unselected hospitalized patients to 23% in the ICU3. The risk of ventilator-associated pneumonia (VAP; a subset of nosocomial pneumonia) is estimated to be 1% per day of mechanical ventilation4. More than half of patients with ventilator-associated pneumonia die during the same hospitalization, although not all deaths are directly related to pneumonia. The attributable mortality (percentage of deaths that would not have occurred in the absence of infection) is lower. In a case-control study of 41 patients who developed nosocomial pneumonia, 44% of the deaths were attributed to infection5.
