Current participant inclusion criteria as of 04/05/2021: 1. Adults =18 years 2. Hospital inpatient with suspected or proven COVID-19 3. FiO2 =0.4 and SpO2 =94% 4. Plan for escalation to intubation if needed Previous participant inclusion criteria: 1. Adults = 18 years 2. Admitted to hospital with suspected or proven COVID-19 3. On 40% oxygen (or greater) with SpO2 <94% 4. Plan for escalation to intubation if needed

Current participant inclusion criteria as of 04/05/2021: 1. Adults =18 years 2. Hospital inpatient with suspected or proven COVID-19 3. FiO2 =0.4 and SpO2 =94% 4. Plan for escalation to intubation if needed Previous participant inclusion criteria: 1. Adults = 18 years 2. Admitted to hospital with suspected or proven COVID-19 3. On 40% oxygen (or greater) with SpO2 <94% 4. Plan for escalation to intubation if needed

1. Adults = 18 years 2. Admitted to hospital with suspected or proven COVID-19 3. On 40% oxygen (or greater) with SpO2 <94% 4. Plan for escalation to intubation if needed

1. Adults = 18 years 2. Admitted to hospital with suspected or proven COVID-19 3. On 40% oxygen (or greater) with SpO2 <94% 4. Plan for escalation to intubation if needed