Mechanical Ventilation for Acute Respiratory Distress Syndrome during Extracorporeal Life Support. Research and Practice

Ventilator-induced lung injury remains a key contributor to the morbidity and mortality of the acute respiratory distress syndrome. Efforts to minimize this injury are typically limited by the need to preserve adequate gas exchange. In the most severe forms of the syndrome, extracorporeal life support is increasingly being deployed for severe hypoxemia or hypercapnic acidosis refractory to conventional ventilator management strategies. Data from a recent randomized controlled trial, a post-hoc analysis of that trial, a meta-analysis, and a large, international, multicenter observational study, all suggest that extracorporeal life support, when combined with lower tidal volumes and airway pressures than the current standard of care, may improve outcomes compared with conventional management in patients with the most severe forms of the acute respiratory distress syndrome. These findings raise important questions not only about the optimal ventilator strategies for patients receiving extracorporeal support, but how various mechanisms of lung injury in the acute respiratory distress syndrome may potentially be mitigated by ultra-lung-protective ventilation strategies when gas exchange is sufficiently managed with the extracorporeal circuit. Additional studies are needed to more precisely delineate the best strategies for optimizing invasive mechanical ventilation in this patient population.