spectrum comparison
Oxygen Delivery Devices: Low-Flow vs High-Flow with FiO2 Ranges
The NCLEX gives you a target SpO2 and asks which device fits. Pick a nasal cannula when the patient needs 80% FiO2 and you've just killed them. Pick a non-rebreather for someone who only needs 28% and you're masking CO2 retention in a COPD patient.
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Side-by-side6 compared
Focus
Comparevs
Dimension
Nasal Cannula
Simple Mask
Venturi Mask
Partial Rebreather
Non-Rebreather
High-Flow NC (HFNC)
Flow rate
- 1–6 L/min
- 5–8 L/min
- Varies by adapter (~4–12 L/min)
- 6–15 L/min
- 10–15 L/min
- Up to 60 L/min
FiO₂ range
- 24–44%
- 40–60%
- 24–50% (precise, dialed)
- 60–75%
- 80–95%
- 21–100% (set independent of flow)
Key feature
- Patient can eat, talk, sleep
- Basic mask: no bag, no jet adapter
- ★Most precise FiO₂ — best for COPD
- Bag refills with first ⅓ of exhalation
- ★Highest FiO₂ of low-flow devices
- Heated, humidified
- Mild PEEP effect
- Patient can eat, talk, sleep
Key nursing care
- Each L ≈ +4% FiO₂
- Humidify if > 4 L/min
- Check nares for skin breakdown
- ★Never run < 5 L/min — CO₂ rebreathing
- Use correct jet adapter
- Don't block entrainment ports
- Bag stays ⅓–½ full on inspiration
- Keep bag fully inflated
- Still hypoxic: escalate (HFNC/NIV)
- Needs blender system
- Check nares for skin breakdown
Flow rate
Nasal Cannula
- 1–6 L/min
Simple Mask
- 5–8 L/min
FiO₂ range
Nasal Cannula
- 24–44%
Simple Mask
- 40–60%
Key feature
Nasal Cannula
- Patient can eat, talk, sleep
Simple Mask
- Basic mask: no bag, no jet adapter
Key nursing care
Nasal Cannula
- Each L ≈ +4% FiO₂
- Humidify if > 4 L/min
- Check nares for skin breakdown
Simple Mask
- ★Never run < 5 L/min — CO₂ rebreathing
★ marks the fact that sets a column apart.
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Clinical Pearl
4% per liter for cannula, Venturi for precision, non-rebreather for max FiO2 before intubation.
Component Topics
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