Ventilare la ARDS oltre la PEEP e il Tidal Volume

ARDS is a severe lung disease characterized by inflammation of the lung parenchyma caused by direct and indirect factors. The inflammation of the lung lead to impaired gas exchange with concomitant systemic release of inflammatory mediators, causing inflammation, hypoxemia and frequently resulting in multiple organ failure. This condition is often fatal, usually requiring mechanical ventilation and admission to an intensive care unit. Acute lung injury (ALI) is is characterized by proteinaceous edema, inflammation, and hemorrhage. Ventilator induced lung injury (VILI) occurs when the lung is directly damaged by the action of mechanical ventilation. Ventilatory factors like tidal volume, inspiratory flow rate, and end-expiratory airway pressure (PEEP) are well studied to understand the nature of the resulting damage. Others non-ventilatory cofactors, like body position, PaCO₂, acid-base state, pulmonary vascular pressure changes, body temperature, concomitant pathologies, and pharmacologic agents, play a role to influence VILI expression. We review a selected subset of these non-ventilatory factors and propose mechanisms for their actions.