Figure 2.

Study flowchart. Among 226 patients admitted to the ICU, 197 patients were positive for SARS-CoV-2. Eighteen were negative for SARS-CoV-2, four were referred to other centers early, and seven did not provide written informed consent. One hundred and eight patients were under invasive mechanical ventilation by tracheostomy or orotracheal intubation during the ICU stay. Among these, 77 patients were subjected to bronchoscopy. Fifty-seven samples were available for microRNA quantification.