To reliably deliver an FiO2 approaching 1.0 during manual ventilation with a self-inflating resuscitation bag (Ambu bag), which setup is required?
- A Reservoir attachment with oxygen flow of 10 to 15 L/min ✓
- B Oxygen flow of 5 L/min without any attachment
- C PEEP valve attached with oxygen flow of 6 L/min
- D Any flow above 2 L/min provided the mask seal is tight
Correct answer: A. Reservoir attachment with oxygen flow of 10 to 15 L/min
Explanation
During re-expansion a self-inflating bag draws in ambient air unless a reservoir bag is fitted. With a reservoir and oxygen flow of 10 to 15 L/min the delivered FiO2 approaches 0.9 to 1.0. Without the reservoir, even high flow gives only about 0.4 to 0.6 because air enters through the intake valve. Mask seal affects tidal delivery but cannot compensate for air entrainment into the bag itself.
Reference: Morgan and Mikhail's Clinical Anesthesiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.