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  Exclusion Criteria:  Patient with limitation of care. Patient with immediate risk to ICU transfer within the first 12 hours Patient with neurological or psychiatric symptoms that interfere with respiratory parameters interpretation. Patient with acute or chronic respiratory disease such as COPD, cancer. Pregnancy, age < 18 of vulnerable profile. Patient refusal to participate or previously included in a clinical research trial.