Hypercapnic Acidosis

The purpose of this study is to determine whether nasal high flow is non inferior to non invasive ventilation (NIV) in the early treatment of patients with acute exacerbation of chronic obstructive pulmonary disease (AE-COPD) and hypercapnic acidosis in the emergency department (ED). After obtaining informed consent, participants will be randomly assigned to receive either nasal high flow or non invasive ventilation (NIV, reference treatment) as respiratory support. Researchers will compare both respiratory support groups to see if their blood gas analysis and respiration return to normal ranges.