New study tests gentler oxygen therapy for COPD patients after ventilator

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

1. Age ≥ 18 years. 2. Established COPD diagnosis (clinical history + prior spirometry confirming persistent airflow limitation, if available). 3. Recently extubated after invasive mechanical ventilation for an acute COPD exacerbation. 4. Mild hypercapnic respiratory failure post-extubation, defined as: PaCO₂ 45-60 mmHg (or ≥10 mmHg above known baseline) and pH ≥ 7.30, and Respiratory rate ≥ 20/min or increased work of breathing. 5. Hemodynamic stability: MAP ≥ 65 mmHg without escalating vasopressors. 6. Adequate airway protection: GCS ≥ 13, no active vomiting, manageable secretions. 7. Oxygenation compatible with noninvasive support (e.g., SpO₂ ≥ 88-92% achievable with FiO₂ ≤ 0.6 during screening). 8. Ability to give informed consent (patient or legal surrogate). Exclusion criteria: 1. Severe acidosis or severe hypercapnia: pH \< 7.30 or PaCO₂ \> 60 mmHg requiring immediate escalation. 2. Impending respiratory arrest or immediate need for re-intubation (severe hypoxemia, refractory distress, profound altered mental status). 3. Severe hypoxemia not compatible with trial modalities (e.g., need for FiO₂ \> 0.8 or PEEP \> 10 cmH₂O to keep SpO₂ ≥ 88%). 4. Hemodynamic instability: shock with rapidly escalating vasopressors, malignant arrhythmia, or active myocardial ischemia. 5. Severe encephalopathy (GCS \< 13) or inability to protect airway. 6. Massive hemoptysis, active upper GIT bleeding, or untreated pneumothorax. 7. Post-extubation laryngeal edema/stridor requiring immediate re-intubation. 8. Absolute/relative contraindications to NIV (mask-based): facial trauma/burns, recent facial/upper airway or gastric surgery, fixed upper airway obstruction, uncontrolled vomiting, severe agitation or mask intolerance. 9. Contraindications to HFNC judged by the treating team (rare; e.g., complete nasal obstruction).