welcome to another medcram lecture. I hear this question a lot: how the crown virus actually kills people. There’s a new article in The Lancet which shows that of the 41 people admitted to the hospital, six of them they died and they were all fans and they all had something called ARDS. ARDS is the way the coronavirus kills. Not just him, but many other viruses, including the flu we have every year. This happens through Acute Respiratory Distress Syndrome (ARDS). I will explain how this happens, so you must first understand the anatomy of the lungs. So I want to show you a tree. There is a tree stem and then branch and then these branches branch further and further until you finally get to the leaves and those leaves they capture the sun’s rays that support photosynthesis and so the tree lives. What happens is that this tree grows through its branches the surface of the leaf. So if you pluck all the leaves and put them on the ground side by side the surface represented by these leaves would be larger than the shadow that the tree makes of the sun.
The same thing happens with your lungs: there is an airway that splits to the right and left main bronchus and then they are subdivided into the right upper, middle and lower lobes and left upper, middle, and lower lobes. So, this is the left side, this is the right, because we are against the patient. And then those things, of course, split in much smaller branches and instead of leaves at the end of it all there is something called the alveoli, which is a very tiny structure it resembles a grape berry, which is reached by air, which of course has oxygen. Here’s how the alveoli looks closer. How many alveoli are there in the human body? About 600 million. They are very very small. Their job is when oxygen-poor blood flows past them to take in the oxygen that enters in the alveoli with air and bring it into the blood.
When this oxygen enters the bloodstream, it goes back to the heart and then to your body and all of you muscles and so you get oxygen. You can imagine that this wall is many thin because the oxygen that comes in here has to pass into the blood stream. So far so good but what happens just like when your finger swells after you hit it in the door because it works inflammation, in the affected area, and inflammation of the lungs causes fluid to escape into the tissue space. What is happening here is, that you are getting a viral infection. The virus also affects your lungs from RDS the whole lung is inflamed not just in one area as it would in pneumonia or one specific area, like the finger example and just stay there One particular finger won’t make your whole arm swell.
No, but the ARDS whole the lungs go crazy with inflammation and what happens is that instead of there the thin area through which the air passes, because of the inflammation that spreads everywhere, a large barrier is formed, fluid that goes into the tissue space. Moreover, these capillaries they start to leak and the fluid starts to leak out into the alveolar space as well and this starts to fill up with a fluid protein fluid that prevents oxygen from entering the bloodstream and so instead of having it blood rich in oxygen, this blood becomes hypoxic.
If you have ARDS you become hypoxic and you find it difficult to breathe. When they do, they set you up and there is nothing that can speed up or slow it down. You must be assisted by a fan so you get enough oxygen and the machine can breathe for you, as after you hit your finger in the door, the inflammation passed away and this fluid eventually disappeared. The key is maintaining breathing during this period while the fluid is leaving. Then again oxygen will be able to pass into the system and you will get oxygen back into your tissues. Here’s another look at what’s going on: the oxygen that enters these terminal structures called alveoli causes the blood to be enriched with oxygen and this blood-rich blood then returns to the heart. Today I’ll show you three things we have learned in the last 20 years that can improve survival in patients who are on ventilators, help them beat the coronavirus or any other such virus, whether it be influenza, is respiratory syncytial virus or any other type of virus to win and recover if you have an ARDS and you are on a fan.
The first thing I’ll look at is surveillance from 2000 and actually before that when we put people the fan and the fan breathes in theirs respiratory tract, what we are trying to do is make sure we breathe patients well and this is important in some situations because oxygen-poor blood also has carbon dioxide that is released by muscle and this carbon dioxide will have to to be removed by ventilatory breathing by exhalation so that CO2 will escape. To do this, we need to make sure that enough air will circulate, with the capacity to remove carbon dioxide. The problem with this is that we we inflate these alveoli and when we release the pressure and let it out the air from them, they will collapse and nothing keeps them open. So they will open and close, open and close … and so we cause a lot of stress and, of course, the whole problem is, that we have inflammation that causes the problem initially and it causes these membranes to become very thick and oxygen cannot enter there, etc.
Breathing these patients with large ones tidal volumes, actually aggravate the inflammation And so the scientists began to wonder what happens if we just put in a lot pressure down here to keep the alveoli open and use only a small amount tidal volume for patients to breathe. Yes, we won’t be able to get that much carbon dioxide from them, but we don’t care as much as we don’t increase it inflammation. So, the first thing we looked at was the low tidal volume that came out at the beginning of the century.
That almost certainly would caused the partial pressure of carbon dioxide (pCO2) in increase the blood so that this is called a low tide strategy and has a 2000 article in the New England Journal of Medicine, which showed that we can influence change and reduce mortality at this time from 40 percent to about 31 percent mortality, which is a huge drop of mortality and all we did was breathe people in different ways using low tide volume. Now that we are breathing at low tidal volume it’s not very comfortable for people and they try to breathe more because they don’t like it increased levels of carbon dioxide.
So they will try to breathe over fan and they will try to breathe differently from what the fan does tells them to do and in these cases patients are usually given a sedative, but if they have been given too many, many bad things can happen to them. They could get it clots in the blood, their blood pressure would drop, etc. So, the second thing that scientists have actually studied paralyzing patients using medicines so that they are perfectly in sync with the fans. And so the second thing is paralysis. Paralysis requires a lot of intensive care in the intensive care unit: you need good support services, good breathing therapists, good care, something you may not get if there is a huge epidemic but you could get it if it paid attention. So this article also published in The New England Journal of Medicine and, by the way, I’ll give everyone a link these articles in the description below, in this article, lower mortality from 41% to 32% and this was published in 2010. What we also began to realize was that patients were in the hospital for some reason, if you ever look at the bed they are on they always lie on their backs and what we decided to do was turn them over and there were a number of reasons for this, so their belly was down and their back up.
We call this positioning on the belly and if done for about 17-18 hours a day can actually reduce the mortality rate, which is estimated to fall from 33 percent to 16 percent This article was published in 2013 and you can see three here breakthrough in the treatment of ARDS, common the path of morbidity and mortality in the coronavirus we are talking about. But the other thing that is interesting is that we can do a lot if we detect the disease early and get people into the hospital and into the intensive compartment and put them on the fans.
We have suitable ways for good treatment and three things, that really improve it. So we have a good chance of not increasing mortality statistics, but let’s survive. And so really the goal The point of showing these innovations is to make sure that people understand medical the context of what is happening. Sometimes these stories are about how emergency measures can to be very scary and for good reasons, but we have to understand what is going on medically, because knowledge is power. If you have other questions for that.