Which oxygen delivery device provides FiO2 approximately 40–60%?

Which oxygen delivery device provides FiO2 approximately 40–60%?

• A. Nasal cannula 24–44%
• B. Simple face mask 40–60%
• C. Venturi mask 24–50%
• D. Non-rebreather mask 70–100%

Answer: (B)

To deliver about 40–60% FiO2, you’d use a simple face mask. It sits over the nose and mouth and, when used at a flow of about 5–10 L/min, blends oxygen with surrounding air to produce roughly that mid-range concentration. Nasal cannula typically provides less oxygen (roughly 24–44%), so it often doesn’t reach the higher end of that range. Venturi masks are designed for precise, lower-to-moderate FiO2, commonly up to around 50% depending on the adapter, so they may not reliably hit 60%. Non-rebreather masks can deliver very high FiO2 (70–100%), which is above the range in question. Therefore, the simple face mask best matches an FiO2 of approximately 40–60%.

To deliver about 40–60% FiO2, you’d use a simple face mask. It sits over the nose and mouth and, when used at a flow of about 5–10 L/min, blends oxygen with surrounding air to produce roughly that mid-range concentration. Nasal cannula typically provides less oxygen (roughly 24–44%), so it often doesn’t reach the higher end of that range. Venturi masks are designed for precise, lower-to-moderate FiO2, commonly up to around 50% depending on the adapter, so they may not reliably hit 60%. Non-rebreather masks can deliver very high FiO2 (70–100%), which is above the range in question. Therefore, the simple face mask best matches an FiO2 of approximately 40–60%.