Using the FiO2 equation, what FiO2 would be predicted for 6 L/min?

Using the FiO2 equation, what FiO2 would be predicted for 6 L/min?

• A. 28%
• B. 44%
• C. 24%
• D. 40%

Answer: (B)

When using a nasal cannula, FiO2 rises by about 4 percentage points for each liter per minute of flow above room air, with a baseline FiO2 of 21%. So the estimated FiO2 at 6 L/min is 21% + (6 × 4%) = 45%. The closest option is 44%, which matches this common approximation. Keep in mind this is an estimate; the actual FiO2 can vary with cannula fit, breathing pattern, and whether the patient breathes through the mouth.

When using a nasal cannula, FiO2 rises by about 4 percentage points for each liter per minute of flow above room air, with a baseline FiO2 of 21%. So the estimated FiO2 at 6 L/min is 21% + (6 × 4%) = 45%. The closest option is 44%, which matches this common approximation. Keep in mind this is an estimate; the actual FiO2 can vary with cannula fit, breathing pattern, and whether the patient breathes through the mouth.