inclusion criteria: - adult patient - with covid-19 pneumonia according to the diagnostic criteria in effect at the time of inclusion or very highly suspected. - patient treated with nasal high-flow - mild, moderate or severe ards: bilateral radiological opacities not fully explained by effusions, atelectasis or nodules; acute hypoxemia with worsening within the previous 7 days, not fully explained by left ventricular failure; pao2/fio2 ratio < 300 mmhg (or equivalent spo2/fio2). - covered by or having the rights to french social security - informed consent

inclusion criteria: - adult patient - with covid-19 pneumonia according to the diagnostic criteria in effect at the time of inclusion or very highly suspected. - patient treated with nasal high-flow - mild, moderate or severe ards: bilateral radiological opacities not fully explained by effusions, atelectasis or nodules; acute hypoxemia with worsening within the previous 7 days, not fully explained by left ventricular failure; pao2/fio2 ratio < 300 mmhg (or equivalent spo2/fio2). - covered by or having the rights to french social security - informed consent