Over the last three decades since the introduction of the term ventilator-induced lung injury (VILI), we have recognized that positive pressure mechanical ventilation can injure the lungs. It is widely recognized that the cornerstone of lung protective ventilation requires control of tidal volume and transpulmonary pressure. On the other hand, there has been considerably less focus on the impact of respiratory rate and flow on VILI. Mechanical power unites the causes of ventilator-induced lung injury in a single variable that incorporates both the elastic and resistive load of the positive pressure breath.6 In other words, mechanical power quantifies the energy delivered to the lung during each positive pressure breath by assessing the relative contribution of pressure, volume, flow and respiratory rate.
Lung-protective mechanical ventilation with low tidal volume and restricted plateau pressure improves survival in ARDS. However, the optimal approach to PEEP titration to minimize VILI is still debated. Should oxygenation, lung compliance, driving pressure or transpulmonary pressure guide adjustment of PEEP in ARDS?