Which oxygen delivery device can deliver the highest portion of FiO2 when used appropriately?

Which oxygen delivery device can deliver the highest portion of FiO2 when used appropriately?

• A. Nasal cannula
• B. Simple face mask
• C. Non-Rebreather
• D. Venturi mask with oxygen

Answer: (C)

The device capable of delivering the highest FiO2 when used correctly is the non-rebreather mask. Its design includes a reservoir bag and one-way valves that prevent room air from diluting the oxygen during inhalation. When you provide a high enough oxygen flow (typically around 10–15 L/min) and keep the reservoir bag well inflated, the patient can inhale near-ambient oxygen content, approaching 100% FiO2 in ideal conditions. The key is maintaining a good seal and sufficient flow so the bag doesn’t collapse during inspiration. Other devices inherently mix in ambient air or have fixed mixtures, so their maximum FiO2 is lower in routine use. A nasal cannula delivers oxygen through the nostrils and is limited by dilution with room air, usually about 24–44% FiO2 even at higher flows. A simple face mask can provide more than a nasal cannula but typically stays in the roughly 40–60% range depending on flow and fit. A Venturi mask can deliver precise FiO2 values by using adapters to mix air with oxygen, but its maximum FiO2 is generally around 50–60% (sometimes higher with specialized setups), which is still less than what a well-used non-rebreather can achieve.

The device capable of delivering the highest FiO2 when used correctly is the non-rebreather mask. Its design includes a reservoir bag and one-way valves that prevent room air from diluting the oxygen during inhalation. When you provide a high enough oxygen flow (typically around 10–15 L/min) and keep the reservoir bag well inflated, the patient can inhale near-ambient oxygen content, approaching 100% FiO2 in ideal conditions. The key is maintaining a good seal and sufficient flow so the bag doesn’t collapse during inspiration.

Other devices inherently mix in ambient air or have fixed mixtures, so their maximum FiO2 is lower in routine use. A nasal cannula delivers oxygen through the nostrils and is limited by dilution with room air, usually about 24–44% FiO2 even at higher flows. A simple face mask can provide more than a nasal cannula but typically stays in the roughly 40–60% range depending on flow and fit. A Venturi mask can deliver precise FiO2 values by using adapters to mix air with oxygen, but its maximum FiO2 is generally around 50–60% (sometimes higher with specialized setups), which is still less than what a well-used non-rebreather can achieve.