Which statement best describes the nasal cannula's typical use?

Which statement best describes the nasal cannula's typical use?

• A. It delivers the highest concentration
• B. It requires a reservoir bag
• C. It delivers no oxygen
• D. It is typically used when long-term oxygen administration is required

Answer: (D)

A nasal cannula is designed for comfortable, ongoing delivery of supplemental oxygen at low-to-moderate flow, making it well suited for long-term use. It does not provide the highest oxygen concentration—that level is achieved with other devices like certain masks that can deliver higher FiO2. It also does not use a reservoir bag, which is a feature of some masks that store oxygen for delivery. Importantly, it does deliver oxygen at all, not zero. Because it’s lightweight and easy to wear for extended periods, it’s commonly chosen for long-term oxygen administration, such as at home or for chronic hypoxemia. In practice, FiO2 with a nasal cannula varies with flow (roughly 24–40% at typical settings), and humidification may be added at higher flows to improve comfort.

A nasal cannula is designed for comfortable, ongoing delivery of supplemental oxygen at low-to-moderate flow, making it well suited for long-term use. It does not provide the highest oxygen concentration—that level is achieved with other devices like certain masks that can deliver higher FiO2. It also does not use a reservoir bag, which is a feature of some masks that store oxygen for delivery. Importantly, it does deliver oxygen at all, not zero. Because it’s lightweight and easy to wear for extended periods, it’s commonly chosen for long-term oxygen administration, such as at home or for chronic hypoxemia. In practice, FiO2 with a nasal cannula varies with flow (roughly 24–40% at typical settings), and humidification may be added at higher flows to improve comfort.