Which device delivers 1 to 6 L/min and up to 24%-44% O2 delivered?

• A. Nonrebreather Mask
• B. Nasal Cannula
• C. Bag Valve Mask
• D. Simple Face Mask

Answer: (B)

Oxygen delivery depends on both the device and the flow you set. The nasal cannula is a low-flow system that delivers oxygen through prongs in the nostrils. Its typical flow range is 1 to 6 L/min, and the approximate FiO2 it provides increases with flow—from about 24% at 1 L/min up to roughly 44% at 6 L/min. This makes it the best match for the given range of 1–6 L/min and 24%–44% FiO2.

Nonrebreather masks deliver much higher FiO2 (usually around 60–95%) but at higher flow with a reservoir, not the 1–6 L/min range. Bag-valve masks can deliver near 100% FiO2 but are used for ventilation, not routine low-flow oxygen. Simple face masks typically require higher flows (about 5–8 L/min) and provide roughly 35–60% FiO2, not the narrow 1–6 L/min with up to 44% FiO2 described here.