What type of oxygen should be used for patients with serious respiratory symptoms?

• A. 50% oxygen via nasal cannula.
• B. 100% oxygen via nasal cannula.
• C. 100% supplemental oxygen via nonrebreather mask or BVM.
• D. No oxygen until symptoms worsen.

Answer: (C)

When someone has serious breathing problems, the goal is to deliver the highest possible concentration of oxygen to counteract hypoxemia. The devices that can provide near-100% oxygen are a nonrebreather mask with a reservoir and a bag-valve mask. With a proper seal and high flow, these setups deliver a very high FiO2, approaching 100%, which is crucial while evaluating and treating the underlying cause of the respiratory distress. A nasal cannula, even at its best, cannot supply that level of oxygen concentration; it typically delivers far less than 100% and may be insufficient for severe symptoms. Waiting to give oxygen until symptoms worsen would allow harmful levels of oxygen deprivation to continue. Therefore, using 100% supplemental oxygen via a nonrebreather mask or bag-valve mask is the appropriate choice in this scenario.