ABG interpretation

Question 1

In a healthy person, what would you expect the PaO2 to be, relative to the percentage of inspired O2?

Answer 1

PaO2 should be 10 less than inspired concentration.

So, on 21% O2 (atmospheric concentration), you would expect a PaO2 of around 11kPa.

On 40% O2, you would expect a PaO2 of 30kPa