What is the maximum safe flow rate for most adult nasal cannulas?

• A. Up to 2 liters per minute
• B. Up to 8 liters per minute
• C. Up to 6 liters per minute
• D. Up to 4 liters per minute

Answer: (C)

The main idea is understanding how much oxygen a nasal cannula can safely deliver in most adults. A nasal cannula is a simple, low-flow delivery method that works well for mild to moderate oxygen needs. It can reliably provide supplemental oxygen up to six liters per minute. Pushing the flow higher than this doesn’t significantly raise the amount of oxygen the person inhales and increases the risk of drying and irritating the nasal passages, plus it may be uncomfortable or ineffective due to the way the device entrains room air. For higher oxygen needs, other devices like masks or high-flow systems are used. So, while lower settings such as two or four liters per minute are still safe, the practical upper limit for a standard nasal cannula is six liters per minute.