What piece of equipment is shown below? Outline the principle of operation of this equipment.

 

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College Answer

Non-rebreather or partial rebreather oxygen mask

Reservoir bag attached to FGF
One way valve between reservoir bag and patient which prevent expired gas entering the reservoir bag.
Usual FiO2 reached is between 60-90%. Achieving 100% FiO2 is difficult because of valve inefficiency and lack of a tight fit around the face thus entraining room air.

Discussion

This question closely resembles Question 15.3 from the first paper of 2012.