Excerpts from Oxygen Therapy for the Emergency Medical Responder

Other oxygen-delivery devices are:

• The nasal cannula is used to deliver low concentrations of supplemental oxygen to a breathing patient.
• A non-rebreather mask that is used to deliver high concentrations of supplemental oxygen.

Now, which of these should you use and when?

Ideally, choose nasal cannula when patients are in mild to moderate distress and need about 25 percent to 45 percent oxygen. These devices can deliver oxygen at the rate of one to six liters per minute.

On the other hand, choose a non-rebreather mask when patients are in moderate to severe distress and need about 80 to 95 percent oxygen. These devices can deliver oxygen at the rate of 10 to 15 liters per minute.

Many times, you’d want to use the blow-by-delivery method for patients who will not tolerate traditional masks or cannula placed on the face. It is especially good for small children.