What is a con of a non-rebreather mask?

• A. Need for humidification
• B. High cost
• C. Bulkiness limits mobility
• D. Risk of asphyxiation

Answer: (D)

Non-rebreather masks are designed to deliver very high concentrations of oxygen by filling a reservoir and using one-way valves to keep exhaled gas out of the reservoir. The major risk with this device is that if the oxygen flow isn’t kept high enough or the bag collapses or valves fail, the patient can end up rebreathing exhaled CO2. Breathing in CO2-rich air reduces ventilation efficiency and can lead to hypercapnia, and in some cases can contribute to dangerous levels of hypoxia—essentially a risk of asphyxiation if the device isn’t supplying sufficient fresh oxygen. To prevent this, set an adequate flow rate (typically 10–15 L/min) to keep the bag inflated and monitor for signs of poor oxygenation or CO2 retention. Other potential downsides like the need for humidification, cost, or bulkiness exist, but they are less directly tied to safety than the possibility of CO2 buildup when the device isn’t delivering enough oxygen.