Inclusion Criteria:  moderate to severe acute respiratory distress syndrome (ARDS) due to COVID-19 with an arterial partial pressure of oxygen divided by the inspired oxygen concentration (P/F) ratio < 150 with a minimum 5 cm of positive end-expiratory pressure on a mechanical ventilator  Exclusion Criteria:  post-cardiac arrest status, premorbid diagnosis of dementia, dependency on extra-corporeal therapies prior to or during ICU stay