Therapy of nosocomial pneumonia

HAP remains a major cause of morbidity and mortality among hospitalized patients. Although early appropriate therapy results in improved outcomes, the cause of HAP frequently is not known at the time antimicrobial therapy is initiated. Most cases of HAP result from microaspiration of oropharyngeal secretions previously colonized with pathogenic bacteria, and the spectrum of potential pathogens is broad. Taking several factors into account can narrow this spectrum, including severity of illness, length of stay before the onset of pneumonia, and presence of risk factors for specific pathogens. When therapy has been initiated, follow-up of microbial studies and careful monitoring of the patient's course is important. The clinical improvement, even when therapy is appropriate, frequently takes days; therapy should not be changed for the first 2 to 3 days unless frank deterioration is noted. Patients who fail to respond or experience clinical deterioration should be re-examined carefully, and thought should be given to the possibility of other noninfectious processes.