Trump was given supplemental oxygen at the WH - NYT

[octoberlib]

7. You're probably right, because the weird thing about hypoxia in COVID

is it can get really low and people don't notice it unless they develop pneumonia or have lung damage.

In serious cases of COVID-19, patients struggle to breathe with damaged lungs, but early in the disease, low saturation isn’t always coupled with obvious respiratory difficulties. Carbon dioxide levels can be normal and breathing deeply is comfortable—“the lung is inflating so they feel OK,” says Elnara Marcia Negri, a pulmonologist at Hospital Sírio-Libanês in São Paulo. But oxygen saturation, measured by a device clipped to a finger and in many cases confirmed with blood tests, can be in the 70s, 60s, or 50s. Or even lower. Although mountain climbers can have similar readings, here the slide downward, some doctors believe, is potentially “ominous,” says Nicholas Caputo, an emergency physician at New York City Health + Hospitals/Lincoln.

https://www.sciencemag.org/news/2020/04/why-don-t-some-coronavirus-patients-sense-their-alarmingly-low-oxygen-levels