A 65-year-old man with a long history of COPD presents to the emergency department with acute worsening of his shortness of breath, increased cough, and purulent sputum. His arterial blood gas shows pH 7.30, PaCO2 65 mmHg, PaO2 55 mmHg, and HCO3 30 mEq/L. What is the most appropriate initial oxygen delivery method for this patient?
✓ Correct Answer: Option C
In patients with COPD and hypercapnic respiratory failure, precisely controlled oxygen therapy with a Venturi mask (24-28% FiO2) is preferred to prevent worsening hypercapnia by suppressing hypoxic respiratory drive.