A patient is placed on 50% oxygen by mask with some relief of her dyspnea. Another arterial blood gas is obtained to evaluate lung function, which shows a PaO₂ of 120 mm Hg. If the previous PaO₂ on room air was 85 mm Hg, has lung function improved from the previous assessment?

Question

Quizplus · Accepted Answer

The increase in PaO2 from 85 mm Hg to 120 mm Hg is due to the administration of supplemental oxygen, not an improvement in lung function. Lung function improvement would be indicated by better gas exchange efficiency, not just a higher PaO2 from increased oxygen supply.

A Patient Is Placed on 50% Oxygen by Mask with Some