To deliver the highest concentration of oxygen with a nonrebreathing mask, what should you ensure?

The correct choice emphasizes the importance of having the reservoir bag preinflated when using a nonrebreathing mask. The reservoir bag serves as a storage for oxygen and allows for a higher concentration of oxygen to be delivered to the patient. When the bag is preinflated, it ensures that there is a sufficient supply of oxygen available for the patient during inhalation, minimizing the risk of dilution with room air.

If the bag is not preinflated, the patient may not receive the intended high concentration of oxygen, as they could draw in room air through the mask while inhaling. This is crucial in emergency situations where maintaining the highest possible oxygen concentration is vital for patient outcomes.

The other considerations, while important in general mask application, do not specifically address the concentration of oxygen delivered. For instance, a secure fit of the mask and appropriate flow rate are relevant for ensuring that the mask functions correctly, but preinflating the reservoir bag directly impacts the efficiency of oxygen delivery.