Is Mechanical Power the One Ring to Rule Them All?

Mechanical power has been proposed as the “unifying currency” to quantify risk of lung injury from the mechanical ventilator. Specifically, it has been suggested that the transmission of energy from the ventilator to the lung as potential, kinetic, and heat energy may cause structural changes at both the cellular and tissue levels. Tidal volume, one key element of the power equation, has been studied extensively; however, although there is physiologic rationale for mechanical power as an integrated measure (flow, pressure, repetitive cycling), there are currently only associations between high mechanical power and poor clinical outcomes.