inclusion criteria: 1. age 18-65 years. 2. clinical evidence of covid-19 (sars-cov2) infection, defined as a positive covid-19 laboratory test plus evidence of an acute hypoxemic respiratory illness requiring oxygen. 3. admitted and transferred to floor without intubation.

inclusion criteria: 1. age 18-65 years. 2. clinical evidence of covid-19 (sars-cov2) infection, defined as a positive covid-19 laboratory test plus evidence of an acute hypoxemic respiratory illness requiring oxygen. 3. admitted and transferred to floor without intubation.

inclusion criteria: age 18-65 years. clinical evidence of covid-19 (sars-cov2) infection, defined as a positive covid-19 laboratory test plus evidence of an acute hypoxemic respiratory illness requiring oxygen. admitted and transferred to floor without intubation.

inclusion criteria: age 18-65 years. clinical evidence of covid-19 (sars-cov2) infection, defined as a positive covid-19 laboratory test plus evidence of an acute hypoxemic respiratory illness requiring oxygen. admitted and transferred to floor without intubation.

inclusion criteria: 1. age 18-65 years. 2. clinical evidence of covid-19 (sars-cov2) infection, defined as a positive covid-19 laboratory test plus evidence of an acute hypoxemic respiratory illness requiring oxygen. 3. admitted and transferred to floor without intubation.

inclusion criteria: 1. age 18-65 years. 2. clinical evidence of covid-19 (sars-cov2) infection, defined as a positive covid-19 laboratory test plus evidence of an acute hypoxemic respiratory illness requiring oxygen. 3. admitted and transferred to floor without intubation.