Mechanical power of ventilation: tracking the damaging component

Mechanical power has emerged as a unifying metric to quantify the risk of ventilator-induced lung injury (VILI), integrating multiple ventilatory parameters-such as tidal volume, airway pressures, respiratory rate, and inspiratory airflow-into a single measure of the mechanical energy delivered to the lungs. However, total mechanical power alone cannot fully predict the likelihood of injury, as the development of VILI depends not only on delivered energy but also on how this energy interacts with the lung's regional mechanical properties and its intrinsic vulnerability to stress. Critically, only externally measured inflation energy that exceeds one or more local alveolar stress thresholds-termed hazardous elastic power-is likely to contribute to lung damage. In this context, we propose a conceptual method to quantify this damaging component of mechanical power in relation to regional stress thresholds for injury. Once refined and validated, incorporating this approach into clinical practice could enhance individualized, lung-protective ventilation strategies by recognizing that VILI arises from the convergence of mechanical energy, regional stress, and structural vulnerability.