inclusion criteria: - patient with covid 19 pneumonia assessed by pcr and ct scann. - patient admited in a dedicated medical ward - patient with oxygen supply less or equal to 4 liters per minute. - written informed consent

inclusion criteria: - patient with covid 19 pneumonia assessed by pcr and ct scann. - patient admited in a dedicated medical ward - patient with oxygen supply less or equal to 4 liters per minute. - written informed consent