Lung and Diaphragm-Protective Ventilation by Means of Assessing Respiratory Work

Lung injury and diaphragm injury incurred by mechanical ventilation have very serious adverse effects on patients with acute respiratory failure. Lung injury results from excessive mechanical stress and strain applied to the lung by the ventilator and/or respiratory muscles, while diaphragm injury results from either insufficient or excessive inspiratory effort. The objective of this study is to investigate a new LDPV strategy designed to prevent both disuse-mediated and load-induced diaphragm injury, while also preventing excess global and regional mechanical stress and strain in the injured lung. To achieve these goals, the following specific targets to be met are: (1) respiratory muscle effort similar to that of healthy subjects breathing at rest, (2) lung stress within safe limits, and (3) clinically acceptable gas exchange. Targets are assessed through measurements of global lung stress, tidal recruitment, inspiratory effort, diaphragm contractile effort and adequacy of respiratory muscle and systemic tissue perfusion. Measurements commence at enrollment and continue for 24 hours consecutively.