Which device is described as a high-flow oxygen delivery device capable of delivering about 95% inspired oxygen at 10–15 L/min?

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

Answer: (A)

Nonrebreathing masks are designed to deliver the highest concentrations of oxygen among common clinical devices. They use a reservoir bag and one-way valves so that most of the inhaled air comes from the supplied oxygen rather than room air, provided the bag stays inflated and a good seal is maintained. At flows of about 10–15 L/min, this setup minimizes entrainment of exhaled or ambient air, allowing inspired oxygen to approach about 95%. The other devices deliver lower FiO2: nasal cannulas typically max out around 40–50% at 6 L/min, simple face masks generally provide roughly 40–60% FiO2 at modest flow rates, and Venturi masks deliver a fixed, precise FiO2 usually in the lower to mid range (not near 95%) depending on the adapter. So the device described is the nonrebreathing mask.