Ventilator-associated pneumonia pathophysiology

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Priyamvada Singh, M.D. [2] Template:Ventilator-associated pneumonia

Pathophysiology

Ventilator-associated pneumonia is primarily caused by the endotracheal or tracheostomy tube allows free passage of bacteria into the lower segments of the lung in a person who often has underlying lung or immune problems. Bacteria travel in small droplets both through the endotracheal tube and around the cuff. Often, bacteria colonize the endotracheal or tracheostomy tube and are embolized into the lungs with each breath. Bacteria may also be brought down into the lungs with procedures such as deep suctioning or bronchoscopy. Whether bacteria also travel from the sinuses or the stomach into the lungs is, controversial. However, spread to the lungs from the blood stream or the gut is uncommon. Once inside the lungs, bacteria then take advantage of any deficiencies in the immune system (such as due to malnutrition or chemotherapy) and multiply. A combination of bacterial damage and consequences of the immune response lead to disruption of gas exchange with resulting symptoms.