Setting and Monitoring of Mechanical Ventilation During Venovenous ECMO

Protective mechanical ventilation is currently the cornerstone of the management of patients with acute respiratory distress syndrome (ARDS). However, mechanical ventilation can cause ventilator-induced lung injury (VILI) through multiple mechanisms, including volutrauma, barotrauma, atelectrauma, myotrauma, and biotrauma. In the context of severe hypoxemia or respiratory acidosis despite conventional mechanical ventilation management, venovenous extracorporeal membrane oxygenation (VV-ECMO) is an established rescue therapy, which can replace pulmonary function. By ensuring full extracorporeal gas exchange, VV-ECMO allows a dramatic decrease in the intensity of mechanical ventilation, which can reduce VILI. In that context, international guidelines and experts recommend ultra-lung protective mechanical ventilation, which combines important reductions in tidal volume, respiratory rate, and plateau and driving pressures. However, the extent to which mechanical ventilation should be reduced, reaching apneic ventilation in some cases, the optimal setting of positive end-expiratory pressure and the potential benefit of proning patients while on ECMO are still matters of debate. This narrative review aims to summarize the current knowledge, rationale, and evidence of mechanical ventilation management and monitoring during VV-ECMO for severe ARDS. It also discusses the research agenda in the field.