How does the coronavirus kill? • Hacker News Board

Re: How does the coronavirus kill?

#11

Post by yread » Sun, Apr 19, 2020, 2:43 PM UTC

ramraj07 wrote: post #7

Only one thing is clear about our immune system: it's extremely complex and even after a century of prodding it, we still don't know it well enough to prod it in targeted ways and know what to expect. Especially, suppressing the immune system is always dicey, since its not just one variable you tune up or down. However, there _is_ a magic bullet of sorts out there, Intravenous immunoglobulin (IVIG). IVIG is just conc…

I read a report on a GBS patient who recovered after getting immunoglobin

Edit: https://www.thelancet.com/journals/laneur/article/PIIS1474-4...

Re: How does the coronavirus kill?

#12

Post by usrusr » Sun, Apr 19, 2020, 2:43 PM UTC

nradov wrote: post #5

usrusr wrote: post #3

Regarding the oxygen saturation levels that have been so much in focus the last few days (the usual thresholds for starting intubation might be wrong for Covid-19 patients): is this a metric that is measured directly or is it usually derived from proxies? That's what my debugging instincts are shouting whenever I read something about the oxygen saturation mismatch, it would be easy to get misled of the proxies have n…

Pulse oximeters measure the light absorbed by hemoglobin. So that's pretty much a direct measurement, I don't think it could be wrong. https://opentextbc.ca/vitalsign/chapter/why-is-pulse-oximetr...

Couldn't there be a million other things that change light absorption?

Re: How does the coronavirus kill?

#13

Post by maxerickson » Sun, Apr 19, 2020, 2:45 PM UTC

ramraj07 wrote: post #7

Only one thing is clear about our immune system: it's extremely complex and even after a century of prodding it, we still don't know it well enough to prod it in targeted ways and know what to expect. Especially, suppressing the immune system is always dicey, since its not just one variable you tune up or down. However, there _is_ a magic bullet of sorts out there, Intravenous immunoglobulin (IVIG). IVIG is just conc…

Isn't the original use of IGIV as a supportive therapy for people not producing antibodies (for whichever reason)?

In the case of COVID-19, plasma therapy (which transfers antibodies from a survivor to an infected) is one of the more promising short term mitigations.

Re: How does the coronavirus kill?

#14

Post by ajross » Sun, Apr 19, 2020, 2:48 PM UTC

usrusr wrote: post #12

nradov wrote: post #5

Earlier quoted context omitted.

Pulse oximeters measure the light absorbed by hemoglobin. So that's pretty much a direct measurement, I don't think it could be wrong. https://opentextbc.ca/vitalsign/chapter/why-is-pulse-oximetr...

Couldn't there be a million other things that change light absorption?

Not inside a body, no. These aren't the most accurate tests (the big failure mode has nothing to do with the science, it's that the little clamp falls off the finger), but they are very mature technology with well characterized behavior.

Basically everyone who's been under anaesthesia of any kind (even stuff like wisdom teeth removal) for the past 3-4 decades has had one of these on them. We know how they work.

Re: How does the coronavirus kill?

#15

Post by ramraj07 » Sun, Apr 19, 2020, 2:50 PM UTC

maxerickson wrote: post #13

ramraj07 wrote: post #7

Only one thing is clear about our immune system: it's extremely complex and even after a century of prodding it, we still don't know it well enough to prod it in targeted ways and know what to expect. Especially, suppressing the immune system is always dicey, since its not just one variable you tune up or down. However, there _is_ a magic bullet of sorts out there, Intravenous immunoglobulin (IVIG). IVIG is just conc…

Isn't the original use of IGIV as a supportive therapy for people not producing antibodies (for whichever reason)? In the case of COVID-19, plasma therapy (which transfers antibodies from a survivor to an infected) is one of the more promising short term mitigations.

Yes, that was the original use. But turns out it has other effects as well, one of which is through the increased dosage of a small fraction of antibodies with increased suppresive activity.

You have to be careful with concoctions that have direct antivirus activity though, because it can have a dangerous side effect (ADE). However this is also a very important intervention possibility (probably more important than just IVIG), but it needs to be done in an extremely controlled fashion. But the two approaches are supposed attack in completely opposite angles so I think they should be discussed and tested independently.

Re: How does the coronavirus kill?

#16

Post by ajross » Sun, Apr 19, 2020, 2:51 PM UTC

ramraj07 wrote: post #7

Only one thing is clear about our immune system: it's extremely complex and even after a century of prodding it, we still don't know it well enough to prod it in targeted ways and know what to expect. Especially, suppressing the immune system is always dicey, since its not just one variable you tune up or down. However, there _is_ a magic bullet of sorts out there, Intravenous immunoglobulin (IVIG). IVIG is just conc…

I don't see how that's going to be meaningfully useful in a pandemic. We don't have anywhere near the infrastructure required to harvest plasma on that scale. It's possible it might be a useful treatment once we get back down to a stable baseline but before a vaccine is available.

I just don't see how the number of lives this will save is going to be significant vs. other more obvious mitigation strategies.

There's a deep temptation among the technical set here to look for magic bullets. There isn't one. Stay home.

Re: How does the coronavirus kill?

#17

Post by ramraj07 » Sun, Apr 19, 2020, 2:53 PM UTC

yread wrote: post #11

ramraj07 wrote: post #7

Only one thing is clear about our immune system: it's extremely complex and even after a century of prodding it, we still don't know it well enough to prod it in targeted ways and know what to expect. Especially, suppressing the immune system is always dicey, since its not just one variable you tune up or down. However, there _is_ a magic bullet of sorts out there, Intravenous immunoglobulin (IVIG). IVIG is just conc…

I read a report on a GBS patient who recovered after getting immunoglobin Edit: https://www.thelancet.com/journals/laneur/article/PIIS1474-4...

Issue with this report and others from China is that they seemed to treat all patients with a concoction of antivirals, one of which is not even available outside of China and russia. No way we can make fully conclusive inferences from this data :(

Re: How does the coronavirus kill?

#18

Post by ramraj07 » Sun, Apr 19, 2020, 2:55 PM UTC

ajross wrote: post #16

ramraj07 wrote: post #7

Only one thing is clear about our immune system: it's extremely complex and even after a century of prodding it, we still don't know it well enough to prod it in targeted ways and know what to expect. Especially, suppressing the immune system is always dicey, since its not just one variable you tune up or down. However, there _is_ a magic bullet of sorts out there, Intravenous immunoglobulin (IVIG). IVIG is just conc…

I don't see how that's going to be meaningfully useful in a pandemic. We don't have anywhere near the infrastructure required to harvest plasma on that scale. It's possible it might be a useful treatment once we get back down to a stable baseline but before a vaccine is available. I just don't see how the number of lives this will save is going to be significant vs. other more obvious mitigation strategies. There's a…

Of course stay home. No one's saying we found the cure. We still want to know what can help patients who get sick anyways (given what's happening in the US now, stupid people make stupid choices but doesn't mean they shouldn't be treated).

Of course I flagged that IVIG could be the worst thing we can try to scale up. Doesn't mean we shouldn't find out if it works or not.

Re: How does the coronavirus kill?

#19

Post by stuff4ben » Sun, Apr 19, 2020, 3:09 PM UTC

m0xte wrote: post #10

Interesting read. My father-in-law died of Covid-19 last week. The thing that got him in the end after a 9 day battle was kidney failure. He had heart problems and diabetes already as underlying conditions. There’s one thing I take away from all of this and that is to eat and live healthy to reduce the things working against you as you get older. Age is bad enough on its own.

Sorry for your loss. You're right about age being bad enough on its own!

Re: How does the coronavirus kill?

#20

Post by joezydeco » Sun, Apr 19, 2020, 3:12 PM UTC

Cameron Kyle-Sidell is a New York ICU doctor that has been trying to help figure out why treatments aren't working as expected. His videos are highly technical but interesting to watch.

Kyle-Sidell believes it's a diffusion hypoxemia problem, leading to pulmonary edema (which is something you see in high-altitude sickness)

https://www.youtube.com/watch?v=NmRlvX3VrAQ&feature=youtu.be

https://twitter.com/cameronks/status/1251259213554335744