Which device is described as delivering the highest typical oxygen flow within the provided ranges?

• A. Non-rebreather mask
• B. Nasal cannula
• C. Simple face mask
• D. Venturi mask

Answer: (A)

The key idea is how each device delivers oxygen flow, not just the oxygen concentration. Among common delivery methods, the non-rebreather mask uses a reservoir bag and one-way valves, so it can supply a high flow of oxygen to keep that bag inflated and to minimize room air mixing during inhalation. This setup typically requires about 10–15 L/min, allowing near-maximal oxygen delivery on each breath. Other devices cap their flow at lower levels: nasal cannulas max out around 6 L/min due to nasal passage limitations; simple face masks generally provide 5–8 L/min (sometimes up to 10) but can be less when the fit isn’t ideal; Venturi masks deliver a precise FiO2 with jet entrainment and usually operate in the 4–12 L/min range depending on the adapter. Because of these design constraints, the non-rebreather mask delivers the highest typical oxygen flow within the provided ranges.