Clinical Research Directory

Inclusion Criteria: 1. Able to understand and sign the informed consent form. 2. Already established diagnosis of COPD according to Global Initiative for Obstructive Lung Disease (GOLD) guidelines.\[13\] 3. Diagnosis of COPD exacerbation at admission, according to GOLD guidelines.\[13\] 4. Arterial partial pressure of oxygen (PaO2) \< 60 mmHg in ambient air at rest at admission and arterial partial pressure of oxygen (PaO2) \> 60 mmHg in ambient air at rest at discharge, if not on long-term oxygen therapy on ventilation. 5. Arterial partial pressure of oxygen (PaO2) \< 55 mmHg on usual oxygen supplement (L/min) and arterial partial pressure of oxygen (PaO2) \> 60 mmHg on oxygen supplement at discharge, if already on long-term oxygen therapy on ventilation. g) Age \<= 90 and \>= 18 years old at randomization. Exclusion Criteria: 1. Heart failure as the main cause of acute respiratory failure 2. Acute pulmonary embolism/chronic pulmonary thromboembolism 3. Interstitial lung disease as the main cause of acute respiratory failure 4. Pneumonia as the main cause of acute respiratory failure 5. Chronic renal failure with dialysis dependence 6. Immunosuppression (i.e. cancer on treatment, post-organ transplantation, HIV-positive, on immunosuppressant therapy) 7. Progressive neuro-muscular disorders 8. Cognitively impaired, dementia or decompensated psychiatric disorder 9. Quadriplegia/Hemiplegia or quadriparesis/hemiparesis 10. Do-not-resuscitate order 11. Any other condition that in the opinion of the investigator may significantly impact with patient's capability to comply with the protocol