Under what circumstance should a nasal cannula be used?

• A. Always preferred over a non-rebreather mask.
• B. Only if the patient will not tolerate non-rebreather mask.
• C. When the patient has a severe nasal injury.
• D. Only for pediatric patients.

Answer: (B)

Deliver oxygen in a way that matches both how much oxygen the patient needs and how well they can tolerate the device. A non-rebreather mask can deliver the highest oxygen concentration, but it requires a tight seal and can be uncomfortable or poorly tolerated. If the patient can’t tolerate that mask—due to claustrophobia, gagging or vomiting, facial injuries, or inability to maintain the seal—the nasal cannula is the next practical option. It delivers a lower but still useful amount of oxygen and is more comfortable, making it appropriate when tolerance or practicality limits the use of a non-rebreather mask. It’s not the choice when the patient needs very high oxygen concentrations and can tolerate the mask, in which case the non-rebreather would be preferred.