IIUC, what medicos have been seeing is deceptively high pulse oximetry, which can lead to the docs thinking the illness is less severe than it is in fact.
All the docs need to see is an obese diabetic female to be on alert. If the pt. has dark green nail polish, the reading is more problematic but these gals usually won’t have that nail polish.
This isn’t news. Why NEJM even published this article is strange.