Blood oxygen saturation testing for COVID-19

City Journal ^ | April 26, 2020 | James R. Copland

[dpwiener]

FDA regulations block usage of a feature in Apple Watches that would help millions of users monitor their blood-oxygen levels. [Many Samsung cell phones have this capability, which is important for COVID-19.]

Millions of Americans own an Apple Watch, which commands roughly a 50 percent share of the smartwatch market. Among its many features, the Apple Watch can take your pulse. It also contains hardware to measure your blood-oxygen levels, and it has been doing so since the watch was released—but the hardware is not operable by the watch’s wearer, who thus cannot obtain the results. Under current FDA regulation, the function is disabled. It’s another example of how federal regulation of the production and distribution of pharmaceuticals and medical devices in the United States is less focused on stopping viruses and other diseases than on blocking private-sector innovators from developing solutions that may not work or might have harmful side effects.

This matters in the Covid pandemic. On April 20, emergency-room doctor Richard Levitan described in the New York Times what he’d observed treating patients in Bellevue Hospital in New York. Levitan had seen many cases of “silent hypoxia,” unknown oxygen deprivation in which “patients without respiratory complaints had Covid pneumonia”—even those admitted to the hospital for non-Covid-related health concerns. By the time most patients made it to the hospital, they had “remarkably low oxygen saturations.” Levitan’s recommendation: “Widespread pulse oximetry screening [as] an early warning system.”

[dpwiener]

Here's an interesting article about how FDA regulations/red tape discouraged Apple from enabling their built-in blood oxygen saturation sensor in Apple Watches. Those might have helped some people with early detection of COVID-19. I researched the topic further, and learned that my Samsung cell phone also has a built in sensor and app to measure that. I immediately used it to test myself (I had a 99% oxygen saturation level, which is fine). I then cancelled my order on Amazon from two days ago for a $65 pulse oximeter, which wasn't due to ship for another two weeks anyway because of the huge demand.

For those who have a Samsung phone with Android operating system (or want to download the Samsung Health App) you have to search a bit to locate the feature. After you open the app, scroll to the "Stress" option and press "Measure". It instructs you to put your finger on the sensor light on the back of the cell phone, and then performs the measurement which will take up to about a minute to complete. When done it displays your pulse bpm (beats per minute) and saturation percentage. I've read a number of comments which say that the measurements are surprisingly accurate, and correlate well with the more expensive pulse oximeter devices.

[21twelve]

THANKS!

I already had it on my phone - don’t recall if I knew that I had it!! 71 bbm and 97% O2. I’m guessing 97% isn’t too bad. (Off to see what good numbers should be.) It did say I had zero stress.

[TheConservator]

I believe anything over 95% is considered normal.

[21twelve]

From the web:

https://www.healthline.com/health/normal-blood-oxygen-level#oxygen-levels

A pulse oximeter (pulse ox) is a noninvasive device that estimates the amount of oxygen in your blood. It does so by sending infrared light into capillaries in your finger, toe, or earlobe. Then it measures how much light is reflected off the gases.

A reading indicates what percentage of your blood is saturated, known as the SpO2 level. This test has a 2 percent error window. That means the reading may be as much as 2 percent higher or lower than your actual blood oxygen level.

This test may be slightly less accurate, but it’s very easy for doctors to perform. So doctors rely on it for fast readings.

*****************************

The article said people with nail polish or cold extremities (I have the later) will get a lower O2 number. 95 to 100 is a good number.

[dpwiener]

My understanding is that anything over a 90% oxygen saturation level is okay. (My own reading has been varying between 95% and 100%.) If it drops significantly below 90% it would be concerning.

[wastoute]

Something people may not be aware of, this measures “Oxygen Saturation” by interacting with Oxy/Hemoglobin in the Infra Red. Which is not the same thing as the Partial Pressure of Oxygen, the number you actually care about. An O2 sat of 90 corresponds to a pO2 of 60. Which is Respiratory Failure territory. So the only numbers you care about on Oxygen Saturation are the #s between 90 and 100. Because that’s the way Hemoglobin Dissociation works. Most people that read these things think it is a direct relationship (which it is not) and that an O2 Sat of 60 means pO2 of 60. So they think a O2 Sat of 80 is OK. It ain’t 80 is DEEP into Respiratory Failure.

Common misconception that frankly makes an O2 sat dangerous in the wrong hands.

[21twelve]

Thanks! I looked it up in post #4, which also answers the question of “How the heck can my phone measure my oxygen level!?”

[Aiden]

My phone has this too, however be very careful as they are not always accurate. My old Samsung S6 was wonderfully accurate. My latest S10+ is terribly inaccurate, often showing me at 72% or lower. I would be having organ damage at that point. I do believe it is a known issue with them, so don’t freak out if it reads low like that. The heartbeat monitor seems to be ok though.

I did notice that when I had the virus, it raised my heart rate from the usual 74bpm to 145bpm for about 4 hours and I averaged 120 for the day. It slowly came down over the next 2-3 days, though a persistent fatigue set in during that time that lasted for a week or so. If you are familiar with your regular heart rate, that may be another way to spot infection *if* you get that symptom. Of all the other folks I know that have had it (7), I was the only one with the raised heartrate. I do not have any other underlying health conditions, but if I did, something like tachycardia (145+) could be a real problem.

[Oscar in Batangas]

Outside of the phrase “an apple a day...”

What the HELL is “FDA regulations” and “Apple” doing in the same conversation???

The SWAMP has overflowed its banks. We’d better find the drain plug pretty soon!!!

[Mom MD]

depends on where you live your age and other health conditions. usually 90% and above is ok thrrr are conditions where 88% is acceptable.

[MAGAthon]

AUDIO: 13m02s: 26 Apr: 3AW: Luke Grant: “Effects of the lockdown are worse than the virus”: The real dangers of COVID-19 could still be ahead of us
Is it really better to be safe than sorry? A leading UK pathology professor warns us that the ramifications of a country going into lockdown could cause more damage than Coronavirus.
Professor John Lee is a writer for the UK Spectator, a retired professor of pathology and a former NHS consultant and he joined Luke Grant on Australia Overnight to give some perspective on the further reaching effects of COVID-19.
“The trouble with it is that they (government) have erred on the side of better ‘safe than sorry’… it’s a general principle of medicine, that when you’re giving a treatment to people, first do no harm.”

Professor Lee shines light on the fact that nations have overestimated the dangers of, and underestimated the danger of a population going into lockdown.
“The lockdown has side effects. From the economic side effects, from direct health side effects… people aren’t accessing health care, to health problems that were storing up for the future like people not coming in for their cancer screenings, not presenting themselves early enough when they have got chest pains for heart attacks.”

Professor Lee also touches on the murky origins of Coronavirus and if we may ever have a cure for the deadly disease.
https://www.3aw.com.au/podcast/effects-of-the-lockdown-are-worse-than-the-virus-the-real-dangers-of-covid-19-could-still-be-ahead-of-us/

[for-q-clinton]

Samsung Galaxy phones have an o2 saturation meter on it. I’ve been using it.

[Mom MD]

depends. At 14000 feet 80% is fine... The real issue is there are 2 components to respiration. — Oxygenation and ventilation. You can die from respiratory failure with a perfectly normal O2 saturation if you are not getting rid of CO2. A pulse oximetry does not measure CO2. there are conditions such as emphysema where we want the pulse ox lower than normal to prevent the build up of CO2. it it takes a blood measurement and experienced physician to determine if you are at risk. For those that retain CO2 too much oxygen is deadly

[Mom MD]

145 is a problem no matter what your underlying health. You could be in a fib and need lifelong anticoagulation to prevent stroke. You could be dangerously dehydrated , low on oxygen or be septic. A heart rate that high should always be a trip to the ER

[Mom MD]

I’m not sure what that has to do with my post but I am no fan of the lockdown

[mrsmith]

Oximeter readings are a lagging indicator of the virus.
You’ll have other symptoms first.
Cool device though.

(Yeah, and I don’t have the source to hand.)

[Eagles6]

How do you access it?

[wastoute]

I’ve never used a pulse ox. The only experiences I have heard about with these things has been anecdotal. Bad anecdotes.

[Texas Fossil]

These guys get it.

COVID-19 Briefing: Current Quarantine Approach Wrong Based on Science | Dr Erickson & Dr Massihi

Part 1
https://www.youtube.com/watch?v=vJprwe_rWeM

Part 2
https://www.youtube.com/watch?v=zb6j7o1pLBw

Full Video
https://www.youtube.com/watch?v=cmjYRJXKixY

[wastoute]

By the way, everyone seems to know that you don’t want to put someone who has “become O2 dependent” for Respiratory drive on a high FIO2. Can you remember ever encountering anybody who was actually dependent on O2 for Respiratory drive? Anybody who actually quit breathing because they wee put on Supplemental Oxygen? Is this one of those things “everybody knows” that may not be true?