Extracellular Vesicles From Mesenchymal Cells in the Treatment of Acute Respiratory Failure

This is a phase I/II, randomized, double-blind, placebo-controlled clinical trial that will evaluate the safety and potential efficacy of therapy with extracellular vesicles (EVs) obtained from mesenchymal stromal cells (MSCs), patients with moderate to severe acute respiratory distress syndrome due to COVID-19 or other etiology. Participants will be allocated to receive EVs obtained from MSCs or placebo (equal volume of Plasma-Lyte A). Blinding will cover the participants, the multidisciplinary intensive care team and the investigators.