The 2009 US CDC NHSN clinical surveillance definition for Download Table The prevalence of suspected ventilator associated pneumonia in Scottish intensive care units Robert Hart, Scott McNeill, Sarah Maclean, Jamie Hornsby, Sarah Ramsay, 2020 What is the definition of hospitalacquired pneumonia (HAP) and how does it differ from ventilatorassociated pneumonia (VAP)? VAP Bundle Ventilator Associated Pneumonia Ventilator Associated Pneumonia ( VAP) is a lung infection that occurs in patients who are on mechanical ventilation for more than 48 hours. A VAP bundle is a set of