Airway Pressure Release Ventilation and High-Frequency Oscillatory Ventilation: Potential Strategies to Treat Severe Hypoxemia and Prevent Ventilator-Induced Lung Injury.

Although lifesaving, mechanical ventilation can itself be responsible for damage to lung parenchyma. This ventilator-induced lung injury is especially observed in already injured lungs of patients with ARDS. New ventilatory approaches are needed to safely treat patients with ARDS, and recent studies have suggested the potential utility of open-lung strategies. Airway pressure release ventilation (APRV) and high-frequency oscillatory ventilation (HFOV) are 2 different open-lung strategies that have been proposed to treat refractory hypoxemic respiratory failure while preventing ventilator-induced lung injury. APRV provides increased airway pressure as a potential recruitment mechanism and allows spontaneous breathing, with the potential benefits of decreased sedation, shorter duration of mechanical ventilation, and improvement in cardiac performance. HFOV delivers very small tidal volumes, to prevent volutrauma, at a constant (relatively high) mean airway pressure, thus avoiding atelectrauma. Despite their theoretical benefits, the utility of APRV and HFOV remains unproven and controversial for the routine treatment of ARDS in adult patients. This review is focused on the theoretical and practical aspects of APRV and HFOV, provides an overview of the current evidence, and addresses their possible use in the treatment of ARDS.