Which device is described as a high-flow oxygen delivery device in the material?

• A. Nonrebreathing mask.
• B. Nasal cannula.
• C. Simple face mask.
• D. Venturi mask.

Answer: (A)

High-flow oxygen systems deliver oxygen at rates that meet or exceed the patient’s inspiratory effort, preventing large amounts of room air from diluting the gas they breathe. The nonrebreathing mask fits this role because it has a reservoir bag and one-way valves that minimize rebreathing of exhaled CO2. When supplied with high flow (around 10–15 L/min), the bag stays filled with near-pure oxygen, so the patient inhales mostly oxygen for a very high fraction of inspired oxygen, often approaching 100% with a good seal. That capacity to push a lot of oxygen toward the lungs quickly is what makes it a high-flow device.

Nasal cannulas deliver relatively low to moderate oxygen concentrations (up to about 40–44%) at modest flow rates, and simple face masks provide a similar range with less control and more dilution. The venturi mask can deliver higher and more precise oxygen concentrations by mixing with room air, but it does so through fixed nozzles and entrainment rather than a reservoir-based, high-flow setup, so it’s not typically labeled as a high-flow device in the same way.