Preventing hospital-acquired pneumonia: Current concepts and strategies

Hospital-acquired pneumonia (HAP) occurs more commonly in nonventilated patients, but infection rates are highest in patients receiving mechanical ventilation. Diagnosis of HAP is frequently made clinically, but quantitative techniques are more specific for the diagnosis of ventilator-associated pneumonia (VAP). Bacterial pathogens, which are the most common etiologic agents, may be part of the patient's endogenous flora or originate from other patients, staff, visitors, or environmental sources. Aspiration, the major route for the entry of bacteria into the lower respiratory tract, may be increased by host factors, surgery, invasive procedures, oropharyngeal and gastric colonization, cross-infection, medications, devices, and respiratory therapy equipment. Recognition of these risk factors will allow application of specific intervention strategies to prevent HAP. Knowledge of specific risk factors, pathogenic mechanisms, and efforts to overcome the existing barriers to prevention should reduce rates of HAP and its associated morbidity and mortality. In this era of cost containment, prevention stategies that are practical and easy to implement must be emphasized.