F_IO₂ delivery increases during inspiration while the BirdMark 7A is operating using air mix. Which of the following contribute to this fact?
I. Increasing pressure in the pressure chamber decreases air entrainment.
II. At 12 cmH₂O, the venturi gate closes.
III. After about 12 cmH₂O, gas flow through the circuit is source gas.
IV. Excess flow (source gas) is directed through the timing cartridge.

Question

Quizplus · Accepted Answer

I. Increasing pressure in the pressure chamber decreases air entrainment, which means more source gas is used, leading to an increase in delivery during inspiration.
II. At 12 cmH2O, the venturi gate closes, allowing less air entrainment and more source gas to be used, which increases delivery during inspiration.
III. After about 12 cmH2O, gas flow through the circuit is source gas, which increases delivery during inspiration.
IV. Excess flow (source gas) is directed through the timing cartridge, which helps regulate the delivery and ensures accurate tidal volume. However, this does not directly contribute to the increase in delivery during inspiration.

FIO2 Delivery Increases During Inspiration While the BirdMark 7A Is

F_IO₂ Delivery Increases During Inspiration While the BirdMark 7A Is