
How does the coronavirus kill? - car
https://www.sciencemag.org/news/2020/04/how-does-coronavirus-kill-clinicians-trace-ferocious-rampage-through-body-brain-toes
======
m0xte
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.

~~~
e40
NYT just has an article about kidney failure being a cause of death for COVID
patients:

[https://www.nytimes.com/2020/04/18/health/kidney-dialysis-
co...](https://www.nytimes.com/2020/04/18/health/kidney-dialysis-
coronavirus.html)

~~~
dominotw
wow. How are we supposed to plan for future calamities like this we cannot
predict what we are going to need for the next pandemic. Looks like we should
overstock everything we could possibly ever need.

~~~
untilted
[https://en.wikipedia.org/wiki/Disease_X](https://en.wikipedia.org/wiki/Disease_X)

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

[https://twitter.com/cameronks/status/1251259213554335744](https://twitter.com/cameronks/status/1251259213554335744)

~~~
ramraj07
The hypothesis suggested in the science article sounds more plausible - these
patients are truly oxygen deprived, but potentially because of the vascular
Nature of the infection, the typical gasping response is not initiated

~~~
danenania
I know nothing about medicine, but is there any way to skip the lungs and give
patients oxygenated red blood cells directly?

~~~
jajag
Yes:
[https://en.wikipedia.org/wiki/Extracorporeal_membrane_oxygen...](https://en.wikipedia.org/wiki/Extracorporeal_membrane_oxygenation)

~~~
danenania
Interesting, thanks. Apparently it's already being used to treat covid-19. But
the potential side effects seem to be nasty and the survival rate not great,
so I guess it's only really a last resort treatment.

Human bodies are just too damn complex. Even when the problem is clearly
identified--a lack of oxygen in the blood--there's no way to just insert more
that doesn't cause a hundred new problems :-/ Natural selection seems to be
really bad at modular design.

~~~
ycombobreaker
> Natural selection seems to be really bad at modular design.

Or the other way around, modular design does not appear to be a requirement
for "success.". We like it for the reduction in complexity but that is
ultimately a tradeoff.

~~~
danenania
Well, it’s successful until it’s not. Nature’s primary approach to debugging
seems to be: you die. We clearly weren’t intended to open up the hood and fix
things.

~~~
pacala
Biology doesn't care about individuals. It cares about populations. The main
mechanism is exponential growth, capable of quickly filling carrying capacity
boundaries of arbitrary size. Individual death is a small setback, as another
branch of the exponential growth tree takes over shortly.

------
ramraj07
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 concentrated antibodies made from plasma of thousands of donors.
Its original use case was to clear out a patients antobodies to suppress any
antibody-mediated autoimmune response, but turns out IVIG can have global
immunosuppressive effects through other mechanisms as well. Importantly, it's
very "benign" \- almost no known side effects, and your general immunity is
still left intact. This has led to extensive use of this drug off-label for
anything dealing with excessive immune responses.

The more and more I think and look, the more I'm convinced IVIG might help
worsening covid patients. Indeed, a case study from China suggests it can be
beneficial (3 of 3 very sick patients fully recovered) but of course a proper
study is needed (IVIG is quite possibly the worst drug to try and ramp up
production). On the other side, a pre-covid trial of IVIG on ARDS patients
(already on EMCO) showed no effect, though I personally felt the study was too
broad. More studies are also needed, because I'm sure any _new_ IVIG made,
since it pools thousands of patients' plasma, is bound to have anti-covid
antibodies as well, and this could have some potentially dangerous effects as
well (Antibody-Dependent Enhancement). But I'm still cautiously optimistic and
am hoping to write to some experts after gathering more data to see what they
think.

~~~
maxerickson
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.

~~~
ramraj07
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.

------
usrusr
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 never been (noticeably) unreliable
before.

~~~
nradov
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...](https://opentextbc.ca/vitalsign/chapter/why-is-pulse-oximetry-
used/)

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

~~~
ajross
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.

~~~
wenc
I read that despite the simple measurement mechanism ("shine a light through a
finger"), the accuracy is generally pretty high (+/\- 2%). This document from
the American Thoracic Society does state some corner cases though [1]. Quote:

"How accurate is the pulse oximeter?

The oxygen level from a pulse oximeter is reasonably accurate. Most oximeters
give a reading 2% over or 2% under what your saturation would be if obtained
by an arterial blood gas. For example, if your oxygen saturation reads 92% on
the pulse oximeter, it may be actually anywhere from 90 to 94%. The oximeter
reading may be less accurate if a person is wearing nail polish, artificial
nails, has cold hands, or has poor circulation."

[1] [https://www.thoracic.org/patients/patient-
resources/resource...](https://www.thoracic.org/patients/patient-
resources/resources/pulse-oximetry.pdf)

~~~
wallflower
One very important thing to note is that the Oxygen - Hemoglobin dissociation
curve has a sigmoidal shape. It is not linear. After a certain point, around
90 %, there is a very sharp drop-off.

[https://en.m.wikipedia.org/wiki/Oxygen–hemoglobin_dissociati...](https://en.m.wikipedia.org/wiki/Oxygen–hemoglobin_dissociation_curve)

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Techasura
I'm not a science person nor do I know how a virus kills a human body but this
one is for sure something amazing. What we can't see can lead you to an
absolute death destroying your whole body, it certainly is quite shocking.
It's 2020 and we are still losing so many lives, yet we are still lucky to be
alive because of the advancement in medicine and health care.

~~~
usrusr
It's a virus that is completely unadapted to the human body, fresh off the
boat from whatever animal it evolved on. It's like an early prototype
medication: it already has the desired effect (reproduction in a body part
that serves as a launch pad for transmission to other hosts), but it's chock-
full off side effects. Unfortunately, it is so good at pre-symptomatic
transmission that those side effects impose very little selection pressure.

At this point we have an interesting link to the topic of contact tracing
apps: if we shift our countermeasures from wholesale isolation to fast,
computerized contact tracing that is fast enough to overtake the
infectivity/symptom last, it will increase the evolutionary advantage of less
damaging strains (asymptomatic cases don't trigger a contacts cascade)

~~~
raverbashing
If you compare it to MERS/SARS it is actually less harmful (at an individual
level) than those. But of course this ends up meaning more harmful at a
collective level since it takes a while for people to develop symptoms while
still being able to infect other people.

------
coldcode
I wonder if there is something in your immune system, maybe genetic or your
viral experience, that determines how well your body will cope with this new
virus. There are reports of really old people (I read a 103 and 99 year old's
stories) who recovered from a bout, yet my niece lost a 30 year old friend.

I guess its like debugging an app you have never seen and the source code is
in a language you barely know; everything seems like a clue as to what is
going wrong, yet much of what you think it's doing is simply a mystery because
you don't understand enough.

Even in 2020 there are mysteries in the human body we simply don't understand
yet.

~~~
ramraj07
This was very true for the H1N1 epidemic but it's not clear something like
this is happening with Covid. If anything, the opposite might be happening
where prior infection with a related virus makes the current infection much
worse.

~~~
cblum
Do you have any sources for that last sentence?

~~~
cowboysauce
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7102551/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7102551/)

~~~
cblum
Thank you, that is super interesting.

I wonder how valid this bit still is:

> the discrepancy between the severity of cases observed in the Hubei province
> of China and those occurring elsewhere in the world

I think at this point we’ve already seen very severe cases in many other
countries, no? I don’t have proper sources though, just thinking of misc news
articles I’ve read.

------
pleasereadthis
please read this report by dr sherif sultan based on consultations with
frontline doctors and postmortem examinations. it forms a coherent picture of
symptoms and medication trials that we keep hearing about.

[https://www.facebook.com/ProfSherifSultan/posts/319343963736...](https://www.facebook.com/ProfSherifSultan/posts/3193439637368071)

Here is a treatment protocol that is being regularly kept up to date with
latest information

[https://www.evms.edu/covid-19/medical_information_resources/](https://www.evms.edu/covid-19/medical_information_resources/)

i fear that well meaning doctors are killing their patients because they don't
have updated treatment protocols: even though so much of this information has
been released in chinese treatment protocols many weeks ago, i still keep
seeing "news" articles with these "new discoveries".

i fear a tragedy of the commons situation where everybody assumes the next guy
already knows. who is responsible for keeping treatment protocols updated and
propogating this information to doctors? much of this information is readily
testable, why are we not hearing either positive or negative feedback to this
data?

please help me get this information out to doctors. even if it is not all
accurate, they can make a better informed judgement. please help me understand
if my understanding of this reality is correct, or how to get more information
about this. thank you for your attention.

~~~
rurban
The updated protocol to change Ventilators to ECMO was distributed at April
11, yes.

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rurban
Latest theory is high correlation with air pollution. NOx and tiny dust
particles.
[https://www.sciencedirect.com/science/article/pii/S004896972...](https://www.sciencedirect.com/science/article/pii/S0048969720321215)

This would explain the extraordinary high death rates in Lombardy, Spain,
Styria, Wuhan,... compared to other regions with worse ICU situation and more
seniors.

~~~
rurban
And esp. Belgium. The highest outlier without proper explanation so far.

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webappguy
I am putting this here to help others. Fry me whateveter. I'm no medical or
WHO but I also prepared and knew it was coming week 1 of Jan. I have made many
accurate predictions weeks or months ahead this while time so time it for what
you paid. It's pulmonary edima 'esque yes, but it's an underlying issue that I
think is a big determining factor in who lives and who dies. Lung capacity
sure is important BUT the lungs strangle themselves by on over immune system
response to fight this aka inflammation. And that's it. Most Americans eat
tons of sugar and carbs. They are walking around already in a state of heavy
gut inflammation unknowingly. Chrone's and IBS are rampant too. I have seen
several people who say the 'normally' struggle with lower immune responses get
through it ok. Because the start with a lower inflammation baseline. Others
are starting already heavily inflamed due to diets, and then when they get
COVID it the lugs over inflame as well causing medicinal issues I don't know
the specifics of but that I think can be deadly. Over inflammation has a name
and it's not good. It can cause all sorts of other issues and being over
inflamed in your lungs well we know what happens then. Fast. Do a prolonged
fast for a few days. Only black coffee and water. This will create new white
blood cells. This will eliminate gut inflammation. It will reset your old
immune system with a healthy new one. You go 72hrs you will also get Autophogy
and new stem cells. I can go on but if my post Sparks your interest, and you
might agree what do you have to lose? A few days without food I do it all the
time. If I'm wrong why not try and save your life by giving you a heads start
with no already in state inflammation? It will be healthy for you either way.
Also look at the curves and national diets.

~~~
jniedrauer
Proposing intermittent fasting as a cure for COVID-19 with no clinical
research is dubious. This is the same as any other quack medicine.

Ironically carb consumption is important to maintain immune function in very
active individuals.

~~~
bodeadly
The poster did not claim it was a "cure". The way I read it was that if you're
gut biome is dysfunctional because you eat too much, that is a factor in the
immune response to SARS-CoV-2. That is actually possible. Resetting your gut
biome with a 72 hour fast is known to provide significant health benefits.
Clearly the poster is not a medical professional and states that fact. But
everything stated is reasonable advice. It's certainly not "quack medicine".

~~~
bb123
That’s an interesting idea. Could you point me at any papers on the subject?

