How Corona virus Kills: Acute Respiratory Distress Syndrome (ARDS) & COVID-19 Treatment
how does the corona virus actually kill people ?
The recent article in The Lancet that showed that of 41 people that were
admitted to the hospital six of them died and all of them were on ventilators
and they died with something called a RDS and a RDS is how the corona virus
kills it's not just the corona virus but many other viruses including the
influenza virus that we have every year how is it that this happens it's
through acute respiratory distress syndrome and I'm gonna explain to you how
that happens so you first have to understand lung Anatomy and to understand
that I like to show you a tree so a tree has a tree stump and then it branches
and then those branches branch and then further those branches branch until
finally you get to the leaves and these leaves capture the sun's rays and
that's what gives you photosynthesis and that's how the tree lives and so what
happens is that this tree and the branches increase the surface area of the
leaves on the tree so that if you were to pluck off all of the leaves and you
were to put them on the ground next to each other the surface area that is
represented by those leaves would be larger than the shadow that is produced by
the Sun on that tree.
what happens with lungs when corona virus enter ?
The same exact thing that happens with your
lungs you've got an airway and then that airway divides into a right mainstream
bronchus and into a left mainstream bronchus and then you have a right upper
lobe you have a right middle lobe right lower lobe left upper lobe and you have
a left lower lobe so this is the left side this is the right because you're
looking at the patient and then these things of course divide into much smaller
branches and instead of leaves at the end of all of these things what you have
is something called an alveoli which is a tiny little small grape like
structure that the air gets into and the air of course has oxygen so what does
this look like on a large scale here's what an alveolus looks like how many
alveoli are there in the human body well there's about 600 million of them
these are very very small so what happens is deoxygenated blood comes by and
its job is to pick up the oxygen that comes in to the alveoli and then when
that oxygen comes in it oxygenates the blood and then that blood goes back to
the heart and then to the body and all your muscles that's how you get oxygen
and so you can imagine that this is very very thin because the oxygen which
comes down here has to diffuse into the bloodstream so far so good but what
happens well just like when you hit your finger in the door your finger swells
that's because there's inflammation occurring where you hit your finger in the
door and inflammation causes a leakage of fluids into the tissue space so what
happens here is that you get a viral infection.
the
virus affects your lungs and with a RDS the whole lung becomes inflamed not
just in one area such as you would have with a pneumonia or one particular area
as an example on your finger and it might just stay in one particular finger in
your whole hand wouldn't swell no with a RDS the whole lung goes crazy with
inflammation then what happens air rather than having a nice thin area
inflammation goes everywhere and you get a large barrier a fluid that goes into
the interstitial space furthermore these capillaries start to become leaky and
fluid starts to leak into the alveolar space as well and this starts to fill up
with liquid proteinaceous liquid liquid that prevents oxygen from getting into
the bloodstream and so rather than having nice oxygenated blood this blood
becomes hypoxic and you become hypoxic if you've got a RDS and you've got a
tough time breathing and that is when you get placed on the ventilator there's
really nothing you can do to speed this up there's nothing that you can do to
slow it down you have to be supported on the ventilator so that you're getting
enough oxygen and that the Machine can breathe for you until just like
everything else after you.
hit
your finger in the door and the swelling goes away this fluid will eventually
go away as well the key though is keeping you supported during that period of
time until the fluid goes away and then once again the oxygen will be able to
go back into the system and you will get oxygen back to your tissues so here's
another look at that we get oxygen that's going down into these criminal
structures called the alveoli they go in to these alveoli and they cause deoxygenated blood to turn into oxygenated
blood and then go back to the heart .
so I'm
going to show you three things today that can improve survival in these patients
who are on ventilators to help them beat coronavirus or for that matter any
other virus whether it be influenza whether it's respiratory
syncytial virus the
other quite virus
for beating and recuperating if you've
got a RDS and
you're on the ventilator therefore
the first thing
that look at is what they noticed back in 2000 and actually before is that when
we put people on the ventilator.
how ventilator work ?
The
ventilator puts a breath into their Airways what we were trying to try to to is we were trying to form sure
that we were ventilating patients well and that is important
in some situations because the blood that is poor in oxygen also has carbon
dioxide which is given up from the muscles well this carbon dioxide would need
to be ventilated to be taken out on exhalation so co2 would be coming out well
in order to do that we got to make sure that enough volume of air was going
back and forth back and forth the problem with that though is that we were
inflating these alveoli and then when we were releasing the pressure and
letting the air out these alveoli would collapse down and nothing was keeping
them open so they would be opening and closing opening and closing shutting and
opening and so that was causing a lot of shear stress and of course what's the
whole problem here that we've got inflammation is what's causing the whole
problem here in the first place and that's causing these membranes to become
very thick and the oxygen can't get in there and so by ventilating these
patients with large tidal volumes we were causing the inflammation to actually
get worse.
than it
would have been if we hadn't done that and so the scientists started to look at
this and say wait a minute what happens if we just put a lot of pressure down
here to keep these alveoli open and only use a small amount of tidal volume to
ventilate these patients and yes we won't be able to get as much carbon dioxide
out of them but we don't really care so long as we're not adding more
inflammation to it and so that first thing that we looked at this is back in
the early 2000s that is came out is low tidal volume and that would almost
certainly cause the pco2 or the partial pressure of carbon dioxide in the blood
to go up so this was called a low tidal volume strategy and sure enough paper
was published in 2000 in the New England Journal of Medicine that showed that
we could affect change and we could decrease the mortality at the time from 40
percent down to about 31 percent mortality so that was a huge drop in mortality and
all we did was we just ventilated people differently using low tidal volume now
when you're ventilating people with low tidal volume it's not very comfortable
they're trying to breathe more because they don't like that increased carbon
dioxide levels and so they would try to breathe over the ventilator and it
would try to breathe differently than what the ventilator was telling them to
do and in these cases we would usually sedate the patients but if we sedated
them too much bad things could happen to them they could get blood clots their
blood pressure would go down and so the second thing that they came up with was
actually paralyzing these patients using medications so that they were in
perfect sync with the ventilators and so that was paralysis paralysis requires
pretty intensive care in the intensive care unit.
Intensive care required ?
you need good ancillary services you need good
respiratory therapists you need good nursing something that you might not get
if there's a huge outbreak but you could get if attention was made to this so
this paper also published in the New England Journal of Medicine and by the way
I'm gonna give links to all of these papers in the description below they were
able to drop the mortality from 41 percent down to 32 percent and this paper
was published in 2010 so far so good what we also started to realize is that
patients within the hospital for whatever particular reason if you ever check out them
in bed they're on their back and what we decided to do was flip them over and
there was a number of reasons for this so that their belly was down and that
their back was up we call this prone positioning and if you do this for about
17 to 18 hours a day you can actually decrease the mortality they found from 33
percent down to 16 percent and this paper was published back in 2013 then you'll see here three breakthroughs in treatment of a RDS .
The ultimate common pathway for morbidity and mortality within the corona virus
that we're talking about but the other thing about this that's interesting is
we can do a lot if we catch it early and we get people into the hospital and we
get them in the intensive care unit and we get them on ventilators and we're
able to appropriately treat them with good quality medical care and three
things that really make a difference then we've got a good chance so that
they're not another statistic of mortality but they survive this and so really
the purpose of putting these updates on is to make sure that people understand
the medical background of what's going on sometimes these stories about how
brakes can be very scary and for good reason but we need to understand
medically.






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