The trial aims to evaluate whether the Airvo 3 device in OptiO2 mode can maintain patients' SpO2 levels within the target range better than manual oxygen titration in hospitalized COPD patients with hypoxemia/respiratory distress.

Inclusion Criteria:

• Has cognitive ability to provide informed consent
• Aged 22 years or older
• Hospitalized with hypoxemia/respiratory distress
• Diagnosis of COPD
• Candidate for/currently prescribed nasal high flow (flow rate of at least 25 L/min) with supplemental oxygen, as assessed by the investigator
• Expected duration of oxygen and nasal high flow therapy >24 hours (not necessarily continuous)

Exclusion Criteria:

• Receiving Non Invasive Ventilation (NIV) or indicated for NIV as per European Respiratory Society /American Thoracic Society guidelines
• Hemodynamic instability (systolic blood pressure <90mmHg or requirement for vasopressor or inotropic support)
• Patient receiving end of life care
• Nasal or facial conditions precluding use of nasal high flow
• Pregnancy or breastfeeding
• Cognitive impairment or impaired consciousness precluding informed consent
• Unsuitable for adhesive finger pulse oximetry, as assessed by the investigator
• Any other condition which, at the investigator's discretion, is believed to present a safety risk to the patient if included
• The presence of any active comorbidities that affect the patient's condition importantly in the next 30 days, as assessed by the investigator
• Has already participated in this clinical trial

Sensitivity of data, data will be used for FDA submission