Pneumonia: challenges in the definition, diagnosis, and management of disease.

Defining health care-associated pneumonia, which includes both hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), is problematic and controversial. Aspiration pneumonia is often included as a subtype of HAP but may be related to community-acquired aspiration events. Scoring systems exist and new surveillance guidelines have been implemented to make early recognition of pneumonia more precise and objective. Management and prevention should follow recommendations, including early empirical therapy, targeted therapy, and limited duration of treatment. Patients with trauma present a challenge to the diagnosis and management of pneumonia, because of increased risk for aspiration and underlying chest and pulmonary injury.