A non-rebreathing facemask fitted with a reservoir bag and functioning one-way valves, supplied with oxygen at 15 L/min, can achieve an FiO2 closest to:
- A 1.00
- B 0.80 to 0.90 ✓
- C 0.60
- D 0.45
Correct answer: B. 0.80 to 0.90
Explanation
With a fully filled reservoir bag, patent one-way valves and a tight fit, a non-rebreathing mask delivers an FiO2 of about 0.80 to 0.90 at flows of 10 to 15 L/min. It cannot reach exactly 1.0 because some mask leakage around the face always entrains room air. The valveless partial rebreathing and simple masks cap out around 0.6, which kills those distractors.
Reference: Morgan and Mikhail's Clinical Anesthesiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.