inclusion criteria: * covid-19, either confirmed by sars-cov-2 assay, or clinically suspected, with results of the assay pending; * lung infiltrates documented on chest x-ray or chest ct-scan; * significant respiratory distress that requires treatment with hfno.

inclusion criteria: * covid-19, either confirmed by sars-cov-2 assay, or clinically suspected, with results of the assay pending; * lung infiltrates documented on chest x-ray or chest ct-scan; * significant respiratory distress that requires treatment with hfno.

inclusion criteria: - covid-19, either confirmed by sars-cov-2 assay, or clinically suspected, with results of the assay pending; - lung infiltrates documented on chest x-ray or chest ct-scan; - significant respiratory distress that requires treatment with hfno.

inclusion criteria: - covid-19, either confirmed by sars-cov-2 assay, or clinically suspected, with results of the assay pending; - lung infiltrates documented on chest x-ray or chest ct-scan; - significant respiratory distress that requires treatment with hfno.