AN APPROACH TO EMPIRIC THERAPY OF NOSOCOMIAL PNEUMONIA

Nosocomial pneumonia is the second most common hospital-acquired infection and the one that is most likely to lead to the death of a patient. Although the crude mortality rate for this infection ranges from 50% to 70%, not all patients who die with pneumonia die because of the presence of infection.(7, 10, 11, 26) When a patient dies because of pneumonia, the infection has led to an attributable mortality and studies have shown that one third to one half of all deaths in patients with nosocomial pneumonia are the direct result of infection.(7, 16) Theoretically, such attributable deaths could be prevented with early diagnosis, appropriate therapy, and effective prophylactic strategies. If antibiotics are to be life-saving, they must be initiated in a timely fashion, and they must have efficacy when used in seriously ill patients. To achieve this goal, empiric therapy is often necessary for patients suspected of having nosocomial pneumonia, even though such an approach is intellectually imprecise and necessarily broad spectrum in nature. This approach is justified by the need to initiate antibiotic therapy while awaiting the results of diagnostic tests that could prove the presence of infection and could identify a specific etiologic pathogen or group of pathogens. At present, empiric therapy of nosocomial pneumonia has been endorsed by an ad hoc international consensus panel, even though our current knowledge of nosocomial pneumonia is incomplete.(18) This incomplete database implies certain limitations to an empiric therapeutic approach, but a more logical and more effective management strategy has not yet been demonstrated. When treating patients suspected of having nosocomial pneumonia, it is important to realize that the diagnosis is imprecise. Clinical criteria for pneumonia are sensitive but not specific, whereas invasive diagnostic testing may be specific but may be defining only a subset of all patients with pneumonia.(8, 24)