Mechanical ventilation is critical for the survival of many patients with the acute respiratory distress syndrome (ARDS) but can also cause ventilator-induced lung injury (VILI). One form of VILI occurs when the lungs exhale to relatively low volumes and airway pressures. This may cause injurious tidal closing and reopening of small bronchioles and alveoli or excessive stress at the margins between aerated and atelectatic airspaces.1,2 In animal studies, positive end-expiratory pressure (PEEP) reduced or prevented VILI from exhalation to low volumes and pressures.1,3- 5 PEEP can also recruit some previously atelectatic or fluid-filled lung regions, allowing more of the lung to be available for inflation during inspiration. This could reduce VILI from overdistention of an otherwise reduced amount of aerated lung.
Sahetya SK, Brower RG. Lung Recruitment and Titrated PEEP in Moderate to Severe ARDSIs the Door Closing on the Open Lung?. JAMA. 2017;318(14):1327–1329. doi:10.1001/jama.2017.13695