Alveolar fibrinolytic capacity is suppressed by injurious mechanical ventilation

Introduction: Intra-alveolar fibrin depositions (i.e., hyaline membranes) are the histological hallmark of the neonatal respiratory distress syndrome (RDS) and acute lung injury (ALI). In ALI, they are the net result of a pro-coagulant milieu, dominated by inhibition of local fibrinolysis due to increased local production of plasminogen activator inhibitor (PAI)-1. Alveolar fibrin inactivates surfactant, leading to severe gas exchange disturbance. Although mandatory for most patients with RDS and ALI, mechanical ventilation causes lung damage by itself. We therefore investigated whether mechanical ventilation al…