PaO2 of 286... is that even possible?

[KDalmostRN]

I am working on a care plan and interpreting lab results. I wrote down that my client had a PaO2 of 286 mm Hg. But is that even possible? Normal PaO2 is 80-100. Also, I wrote down that his base excess was 100, which is way out of the normal range. His pH was only 7.34, which isn't too far from normal. I've been looking through my books and searching the internet, but I can't seem to make sense of it. Any help would be appreciated! :)

(These were admission values on an older man with HTN, COPD/emphysema, and arterial occlusive disease who came in d/t ischemia of his BKA RLE, which was then revised to an AKA)

[twss2323]

Yes it is possible. There's a formula and I wish I could explain it better without looking it up... But long story short, PaO2 should be about 5× more than Fi02 in a healthy person. Room air is 21% Fi02, so a person with perfect lungs theoretically should have a PaO2 of 105.

I'm guessing your patient was on oxygen of some sort?

[KDalmostRN]

Thank you! Yes, he was on O2 BNC at 3L/min. But I don't know if he was on O2 at the time his admission labs were taken. I was taking care of him 2 days post-op. All I could think is that they may have been giving him a high concentration of supplemental O2 at the time the labs were drawn.