Effect of APRV and LTV on Lung Ventilation and Perfusion in Patients With Moderate-to-severe ARDS

Low tidal volume ventilation (LTV) has been proposed and widely used in patients with acute respiratory distress syndrome (ARDS) to prevent ventilator-induced lung injury (VILI) and mitigate its effects. The LTV strategy is intended to protect the "baby lung" from overdistension while simultaneously allowing acutely injured tissue to continually collapse. Airway pressure release ventilation (APRV) is a highly effective strategy improving lung recruitment and oxygenation in clinical studies, but its effects on lung injury and mortality is debatable. Animal studies revealed that APRV could normalize post-injury heterogeneity and reduce the risk of VILI. Our objective was to investigate the impact of APRV and LTV on regional ventilation and perfusion distribution in ARDS patients by electrical impedance tomography (EIT).