What is the percent oxygen provided by a nasal cannula?

What is the percent oxygen provided by a nasal cannula?

• A. 24% - 44%
• B. 4% - 24%
• C. 44% - 50%
• D. 50% - 55%

Answer: (A)

Nasal cannula oxygen delivery is flow-dependent and mixes supplemental O2 with room air the patient naturally inhales. The common rule of thumb is about 4% O2 increase per liter per minute, starting from room air at roughly 21%. That means at low flow you get around 24%, and as you raise the flow up to about 6 L/min you approach roughly 44%. Because a nasal cannula can’t reach the higher oxygen concentrations that other devices can achieve, the practical range sits around 24% to 44%. So the range 24%–44% best fits the actual oxygen delivered by a nasal cannula.

Nasal cannula oxygen delivery is flow-dependent and mixes supplemental O2 with room air the patient naturally inhales. The common rule of thumb is about 4% O2 increase per liter per minute, starting from room air at roughly 21%. That means at low flow you get around 24%, and as you raise the flow up to about 6 L/min you approach roughly 44%. Because a nasal cannula can’t reach the higher oxygen concentrations that other devices can achieve, the practical range sits around 24% to 44%. So the range 24%–44% best fits the actual oxygen delivered by a nasal cannula.