[conradev]

On their best days, they're accurate to within 2-4%. But so many things can trip up the reading, like melanin:

  As a result, for darker-skinned patients, oxygen saturation readings can read as normal when they are, in fact, dangerously low.

https://publichealth.jhu.edu/2024/pulse-oximeters-racial-bia...

When everyone starting looking at every percentage point of their SpO2 during COVID as if it were life or death, the FDA had to remind people of this:

https://www.fda.gov/news-events/fda-brief/fda-brief-fda-warn...

You would be unable to read an accurate pulse oximeter at 80% because you would have lost consciousness. Doctors have to worry about false negatives just as much as false positives with those things.

[mint5]

80% at sea level is very bad. 80% while asleep at 11,500 ft is not unusual. Ref: https://pmc.ncbi.nlm.nih.gov/articles/PMC10157825/

There’s a chart somewhere in there on mean sleep so2 by elevation

[rafram]

Big news for the 0.18% of the world’s population that lives above 11,500 feet, I guess.

[skeeter_sky]

Or sleeps on a plane