Which device delivers moderate oxygen (6-10 L/min)?

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

Answer: (B)

Understanding oxygen delivery devices and their typical flow rates is essential. A nasal cannula provides the lowest flows, usually up to about 6 L/min, delivering modest increases in FiO2. A simple mask delivers a higher flow and a greater FiO2 when you set it around 6–10 L/min, making it a common choice for moderate oxygen needs. A nonrebreather mask can push FiO2 very high, generally requiring higher flows near 10–15 L/min to keep the reservoir full. A bag-valve mask is used for manual ventilation and can deliver high oxygen content, but only when actively ventilating the patient.

So for a delivered oxygen range of 6–10 L/min, the simple mask is the best fit because it reliably provides moderate oxygen delivery within that flow range.