A simple mask can deliver what percentage of FIO2 at how many liters/minute?

a. 0.24 to 0.44 at 1-6 L/min c. 0.40 to 0.60 at 10-15 L/min
b. 0.35 to 0.50 at 5-10 L/min d. 0.50 to 0.80 at 5-10 L/min

ANS: B
The simple mask can deliver a higher concentration than a nasal cannula because of the volume of the mask itself. That volume serves as an extension of the anatomic reservoir. The simple mask is generally said to be able to deliver 0.35 to 0.50 at oxygen flows of 5 to 10 L/min.