title: Physiology in Medicine: Understanding dynamic alveolar physiology to minimize ventilator-induced lung injury.
abstract: Acute respiratory distress syndrome (ARDS) remains a serious clinical problem with the main treatment being supportive in the form of mechanical ventilation. However, mechanical ventilation can be a double-edged sword: if set improperly, it can exacerbate the tissue damage caused by ARDS; this is known as ventilator-induced lung injury (VILI). To minimize VILI, we must understand the pathophysiologic mechanisms of tissue damage at the alveolar level. In this Physiology in Medicine paper, the dynamic physiology of alveolar inflation and deflation during mechanical ventilation will be reviewed. In addition, the pathophysiologic mechanisms of VILI will be reviewed, and this knowledge will be used to suggest an optimal mechanical breath profile (MBP: all airway pressures, volumes, flows, rates, and the duration that they are applied at both inspiration and expiration) necessary to minimize VILI. Our review suggests that the current protective ventilation strategy, known as the "open lung strategy," would be the optimal lung-protective approach. However, the viscoelastic behavior of dynamic alveolar inflation and deflation has not yet been incorporated into protective mechanical ventilation strategies. Using our knowledge of dynamic alveolar mechanics (i.e., the dynamic change in alveolar and alveolar duct size and shape during tidal ventilation) to modify the MBPso as to minimize VILI will reduce the morbidity and mortality associated with ARDS.
authors.affiliation: State University of New York Upstate Medical University, Syracuse, New York.
authors.forename: Gary F
authors.initials: GF
authors.lastname: Nieman
authors.affiliation: State University of New York Upstate Medical University, Syracuse, New York; satalinj@upstate.edu.
authors.forename: Josh
authors.initials: J
authors.lastname: Satalin
authors.affiliation: State University of New York Upstate Medical University, Syracuse, New York.
authors.forename: Michaela
authors.initials: M
authors.lastname: Kollisch-Singule
authors.affiliation: R Adams Cowley Shock Trauma Center, Baltimore, Maryland.
authors.forename: Penny
authors.initials: P
authors.lastname: Andrews
authors.affiliation: State University of New York Upstate Medical University, Syracuse, New York.|Suez Canal University, Ismailia, Egypt; and.
authors.forename: Hani
authors.initials: H
authors.lastname: Aiash
authors.affiliation: R Adams Cowley Shock Trauma Center, Baltimore, Maryland.
authors.forename: Nader M
authors.initials: NM
authors.lastname: Habashi
authors.affiliation: State University of New York Upstate Medical University, Syracuse, New York.|State University of New York Cortland, Cortland, New York.
authors.forename: Louis A
authors.initials: LA
authors.lastname: Gatto
mesh_terms: D006801:Humans; D011650:Pulmonary Alveoli / Q000502:physiology*; D012123:Pulmonary Ventilation / Q000502:physiology*; D012121:Respiration, Artificial / Q000009:adverse effects / Q000379:methods*; D012128:Respiratory Distress Syndrome / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D055397:Ventilator-Induced Lung Injury / Q000209:etiology / Q000503:physiopathology* / Q000517:prevention & control*
keywords: acute lung injury; acute respiratory distress syndrome; mechanical ventilation; positive end-expiratory pressure; ventilator-induced lung injury