What is the maximum flow rate for high-flow nasal cannula?

What is the maximum flow rate for high-flow nasal cannula?

• A. 6 L/min
• B. 60 L/min
• C. 15 L/min
• D. 25 L/min

Answer: (B)

High-flow nasal cannula systems are designed to deliver heated, humidified gas at very high flow rates. In adults, the practical ceiling is about 60 L/min. This upper limit comes from the capabilities of standard HFNC devices and safety/comfort considerations for the patient. At these high flows you get nasopharyngeal dead-space washout and a small amount of positive airway pressure, which together improve oxygenation and reduce the work of breathing. Lower flows won’t fully exploit the benefits of HFNC, while going beyond about 60 L/min is not routinely supported by typical equipment and can cause discomfort or issues with humidification and airway tolerance.

High-flow nasal cannula systems are designed to deliver heated, humidified gas at very high flow rates. In adults, the practical ceiling is about 60 L/min. This upper limit comes from the capabilities of standard HFNC devices and safety/comfort considerations for the patient. At these high flows you get nasopharyngeal dead-space washout and a small amount of positive airway pressure, which together improve oxygenation and reduce the work of breathing. Lower flows won’t fully exploit the benefits of HFNC, while going beyond about 60 L/min is not routinely supported by typical equipment and can cause discomfort or issues with humidification and airway tolerance.