corona virus actually kill people there's a 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 well it's the same exact thing

that happens with your lungs you've got an airway and then that airway divides

into a right mainstem bronchus and into a left mainstem 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

entire lung becomes inflamed not just in one area like you would have with a

pneumonia

or one particular area for instance on your finger and it would just stay in

one particular finger in your whole hand wouldn't swell no with a RDS the entire

lung goes crazy with inflammation and so what happens air instead of 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 instead of having

nice oxygenated blood this blood becomes hypoxic and you become hypoxic if you

have a RDS and you have a hard time breathing and that's 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 we have learned in the last 20 years 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 be respiratory

syncytial virus any other kind of virus for beating and getting better if you

have a RDS and you're on the ventilator so 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 and the ventilator puts a breath into their

Airways what we were trying to do is we were trying to make sure that we were

ventilating patients well and that's 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 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 in the hospital for

whatever particular reason if you ever look at 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 and so you can see here three

breakthroughs in treatment of a RDS the final common

pathway for morbidity and mortality in the coronavirus 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 what

it is that's going on because knowledge is power if you have any other questions

about this please visit my site at make cram comm thanks for joining us