What is the oxygen flow rate for a nasal cannula?

• A. 1-6 L/min
• B. 0-1 L/min
• C. 7-12 L/min
• D. 15-20 L/min

Answer: (A)

The nasal cannula is a low-flow oxygen delivery method, designed to provide modest amounts of oxygen while allowing the patient to breathe ambient air at the same time. The typical flow range for this device is 1 to 6 liters per minute. This range is chosen because it reliably increases the fraction of inspired oxygen (FiO2) without causing discomfort or drying of the nasal passages. In practical terms, around 1 L/min gives a small FiO2 boost (roughly in the low 20s percent), and about 6 L/min gets closer to the mid-40s percent FiO2. When higher oxygen needs are present, or when very precise high FiO2 is required, other devices are used instead of a nasal cannula. Flows below 1 L/min aren’t standard for this device, and flows well above 6 L/min exceed what a nasal cannula can safely and effectively deliver.