One hundred adult patients (aged between 18 and 75y) with laboratory confirmed diagnosis of COVID-19 pneumonia, presenting with severe COVID-19 pneumonia, who fail oxygen therapy by facemask, will be included in this study after ethics committee approval and informed written consent from the patients or their legally acceptable representatives.

One hundred adult patients (aged between 18 and 75y) with laboratory confirmed diagnosis of COVID-19 pneumonia, presenting with severe COVID-19 pneumonia, who fail oxygen therapy by facemask, will be included in this study after ethics committee approval and informed written consent from the patients or their legally acceptable representatives.

One hundred adult patients (aged between 18 and 75y) with laboratory confirmed diagnosis of COVID-19 pneumonia, presenting with severe COVID-19 pneumonia, who fail oxygen therapy by facemask, will be included in this study after ethics committee approval and informed written consent from the patients or their legally acceptable representatives.

One hundred adult patients (aged between 18 and 75y) with laboratory confirmed diagnosis of COVID-19 pneumonia, presenting with severe COVID-19 pneumonia, who fail oxygen therapy by facemask, will be included in this study after ethics committee approval and informed written consent from the patients or their legally acceptable representatives.