Which oxygen delivery device is best for a patient with COPD to maintain a precise FiO2?

• A. Nasal Cannula
• B. Simple Face Mask
• C. Venturi Mask
• D. Non-Rebreather Mask

Answer: (C)

In COPD you want to deliver a specific, controlled amount of oxygen to avoid both hypoxemia and the risk of CO2 retention from too much supplemental oxygen. The Venturi mask is designed for that exact need. It delivers a fixed FiO2 using color-coded adapters that set the precise oxygen concentration and mix in room air to achieve that target. Because the FiO2 is fixed and the device isn’t highly dependent on how the patient breathes, it maintains a stable oxygen level even with changes in tidal volume or breathing pattern. That precision is what makes it the best choice when a clinician needs to titrate oxygen to a specific concentration, typically within a moderate range (about 24% to 50% depending on the adapter).

Other devices don’t offer the same steadiness. A nasal cannula provides oxygen with a variable FiO2 that depends on how much the patient breathes and can breathe through the mouth or nose, making the delivered concentration inconsistent. A simple face mask can supply more oxygen but still varies with breathing and is less predictable. A non-rebreather mask can deliver high oxygen concentrations, but the FiO2 isn’t as reliably fixed and it’s not ideal for COPD patients who require careful titration to avoid CO2 retention.