A lung infection that develops in a patient who is on a ventilator.

VAP is the most common infection acquired in intensive care units and is associated with high mortality. It can be caused by multiple microbes and the need to treat rapidly leads to use of broad-spectrum antibiotics. Treatment is increasingly difficult in many settings due to drug-resistant infections, particularly multidrug-resistant Acinetobacter baumannii and other ‘ESKAPE’ pathogens.

The organisms responsible for VAP are generally different from those causing pneumonia outside the hospital (community-acquired pneumonia).