Hospital acquired (HAP) and ventilator acquired (VAP) pneumonia
Pneumonia is a very common illness. Hospital-acquired pneumonia tends however to be more serious as the patient’s defense mechanisms against infection often are impaired during a hospital stay. HAP is the second most common nosocomial infection in the United States. It is one of the most common diagnoses made in ICUs and is very common in patients undergoing mechanical ventilation (VAP). The most common pathogens isolated include aerobic Gram-negative bacilli such as Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter species and less commonly Eschericia coli and Stenotrophomonas maltophilia as well as Gram-positive organisms such as Staphylococcus aureus. Ventilation-associated pneumonia (VAP) can be separated into early or late infections, with late infections defined as occurring after 5 days of intubation. Late infections show an increased likelihood of multidrug-resistant Gram-negative organisms.