[FRIAM] COVID SaO2 at 7k feet

[uǝlƃ ☤>$]

Well, it's worth noting that SpO2 is *not* a good approximation to SaO2 under a pretty large variety of conditions. So, given that most of our electronic health record data is seriously dirty already, adding even more, dirtier, data doesn't seem all that useful to me.

Add to that the fact that normal people don't even use any health apps at all (e.g. <https://www.healthit.gov/data/data-briefs/individuals-access-and-use-patient-portals-and-smartphone-health-apps-2020>) and whatever data we do get from such devices will probably be too biased to be statistically useful, at least until we de-bias it.

But de-biasing data isn't very easy. Crossing threads back to the inverse map from phenomena to generator: https://www.thelancet.com/journals/landig/article/PIIS2589-7500(21)00137-0/fulltext
"Accuracy was greater in White (90%, 89–91) and Hispanic populations (91%, 88–94) than in African (84%, 81–87) and Asian populations (82%, 78–86; table)."

On 9/28/21 7:31 AM, Steve Smith wrote:
> 
> When COVID hit, I was using a fitness band that was *capable* of reading
> SPO2 but it required a deliberate "stop and hold the band tight against
> the wrist and trigger and take several readings but accept the
> highest"...  there were one or more new "fitness rings" out which
> presumably did better (better contact with capillary rich skin.   
> 
> It seemed to me that were such devices *widely* available, they could be
> used to predict COVID before other symptoms (it seemed like low SPO2 was
> an early symptom) grew noticeable.   At the time, we were most worried
> (and rightly I think) about RO numbers and fast self-quarantine would
> cut the contact-component down fast (for anyone out and about) down
> better than anything.
> If wishes were fishes.
>> Ah, I see. No,this infection is run of the mill. Just snort some salt water and wait it out. I monitored my SpO2 as a signal whether to get a covid test. Since it never dropped very low, I had no fever, no loss of smell/taste, etc., I didn't bother to get a covid test. Had any one of those obtained, I would have gotten a pcr.
>>
>> Thanks for the idea that low SpO2 might require more heartbeats. I hadn't thought of that either.
>>
>> On September 27, 2021 6:05:23 PM PDT, Steve Smith <sasmyth at swcp.com> wrote:
>>> On 9/27/21 4:11 PM, uǝlƃ ☤>$ wrote:
>>>> What am I struggling with?
>>> "But while fighting my infection"   I took this to mean you were "struggling" with an infection.  I understand/appreciate that your SPO2 numbers weren't necessarily causing you any symptoms... I assume you were measuring them for some reason though?   Curiousity I get... I used mine as crude biofeedback to (re)learn how to breath properly, but most of the time I was taking readings out of curiosity...  trying to understand correlations between what felt like a good, hard measure (SPO2) and various activities and symptoms.
>>>
>>>>  Thanks for the stories about SpO2. They nicely demonstrate that variation is normal. To be clear, when I talk about SpO2, I'm not talking about symptoms at all. I'm simply talking about the number that comes from the little machine. I've never had any symptoms that correlate with a low SpO2 measurement. And I think your (and Nick's) stories indicate that there's little, if any, correlation between the two (symptoms and low SpO2).
>>> I'd say that the effects of low SPO2 are less obvious (to a point) than
>>> one would imagine...  I can't say that when I was down in the 70s, there
>>> was no correlation with my fatigue, chills, blue lips and fingernails,
>>> etc...
>>>> However, what was interesting to me during this very normal cold was my elevated heart rate. Even though I quit running seriously about 5 years ago, my resting heart rate is ~63. I've never really monitored it through other infections. But because I happen to have that number along with SpO2, now, I noticed that at the nadir/height of the infection, my resting heart rate was ~100 or ~90 bpm. It's about 80 now, on day 10 since symptoms started. It just never crossed my mind that infections like the rhino would raise your heart rate. But I guess it's common.
>>> One might guess that low SPO2 might raise your heart rate to deliver the
>>> same amount of O2 per unit time?


-- 
"Better to be slapped with the truth than kissed with a lie."
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