Certified Respiratory Therapist Exam 2025 – 400 Free Practice Questions to Pass the Exam

The non-rebreather mask is designed to deliver the highest concentration of oxygen among the listed options. This device features a reservoir bag that allows for the accumulation of oxygen, which is delivered directly to the patient. The mask is equipped with one-way valves that prevent the patient from inhaling room air and ensures that most of the exhaled air escapes without mixing with the incoming oxygen. This effectively provides a high concentration of oxygen, often reaching levels of 90% or more, making it suitable for patients with severe respiratory distress or emergencies where high oxygen levels are critical.

In contrast, other devices such as the nasal cannula and simple face mask deliver lower concentrations of oxygen, typically in the range of 24% to 60%. The Venturi mask is designed for precise control of oxygen concentration but is limited to specific FiO2 levels depending on the adapter used. Therefore, the non-rebreather mask is the only device in this list that consistently provides the highest amounts of supplemental oxygen.