A 75-year-old man with COPD presents with acute onset of worsening dyspnea and agitation. ABG shows PaO2 40 mmHg, PaCO2 65 mmHg, and pH 7.25. The most appropriate management is?

• A. Oxygen supplementation with 100% non-rebreather mask
• B. Noninvasive positive pressure ventilation
• C. Endotracheal intubation and mechanical ventilation
• D. Emergency tracheostomy

Answer: (C)

In COPD exacerbations with worsening ventilation, the key issue is hypercapnic respiratory failure with an acidemic pH. Here, the patient has severe hypoxemia (PaO2 of 40 mmHg) and marked hypercapnia (PaCO2 of 65 mmHg) with a pH of 7.25, indicating that ventilation is not adequate to clear CO2 and maintain acid-base balance. Oxygen alone can't correct the CO2 retention, and giving oxygen via a 100% non-rebreather mask can actually worsen CO2 retention in chronic CO2-retaining COPD by altering ventilation-perfusion dynamics and removing the drive to breathe at a steadier rate.

The patient is agitated, which raises concern for an unsecured airway and reduces the likelihood of successful noninvasive ventilation, since NIV requires patient cooperation and stable mental status. In the setting of significant acidosis (pH 7.25) and airway protection concerns, securing the airway and providing controlled ventilation is necessary. Endotracheal intubation with mechanical ventilation allows precise control of ventilation, effective CO2 removal, and protection of the airway, which are essential to correct both the hypoxemia and the hypercapnic acidosis in this scenario. After intubation, ventilation can be tailored to a COPD-lung–friendly strategy with careful management of tidal volumes, respiratory rate, and PEEP to minimize dynamic hyperinflation while improving oxygenation.