Gas Exchange and Altitude Acclimatization with Dr Patrycja Jonetzko

Patrycja
Often the fittest people were the sickest. Uh, and that’s because they were pushing themselves too hard and they were not paying attention to how their bodies were trying to tell them to slow down. So, it was almost like almost the opposite of what I was expecting.

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Steve House
Welcome to the Uphill Athlete Podcast. My name is Steve House. We have a really exciting episode for all the science geeks out there that are fans of the pod. Today, we are going to go deep into understanding the gas exchange and how oxygen goes from the air into the working muscles. And with us today, we have the incredible Dr. Jonetzko.

Steve House
Welcome.

Patrycja
Welcome, lovely to be here. They say never meet your legends. Hopefully this is going to be a different experience we’re everybody for both of us.

Steve House
Yeah, you get you can that’s a risk, right? You get could be disappointed by that.

Patrycja
Yeah.

Steve House
And i’ve I’ve had it go both ways myself.

Patrycja
Mm-hmm.

Steve House
So hopefully we are positive where we we leave I leave a positive impression. So um I want to frame this up for mountain athletes real quick, what we’re doing.

So whether you’re… as a listener, whether you’re planning on climbing Denali or doing a ski mountaineering event, you’re you’re running in the mountains, your performance ultimately comes down to how efficiently your body can extract oxygen from the atmosphere and get it to the working muscles.

Patrycja
Mm-hmm.

Steve House
Patrycja Jonetzko is a cardiothoracic anesthetist whose daily work involves managing this oxygen delivery to patients in highly critical circumstances during surgery.

Steve House
She has about two decades of supporting all kinds of Himalayan expeditions as an expedition doctor, and most recently was the expedition doctor for the historic, without supplemental oxygen ski descent of Everest done by fellow Paul Andrej Barguil just recently, just a few, just like few, it wasn’t that long ago, what six months ago now or less. So welcome Patrycja. And it’s really great to have you here, and I’m really excited to dig into your knowledge.

Patrycja
Thank you.

Steve House
So let’s let’s start off a little bit with your background. You grew up as a competitive ski racer in Poland. Did that exposure to a life in the mountains lead you into medicine and then into being interested in high altitude physiology or was is that connected at all?

Patrycja
um yes very much so so um yes I did a lot of competitive skiing until the age of about 13 then it ended because my parents didn’t want me to go to a boarding school for you know sports sort of boarding school and I often say that’s when everything went wrong in my life ah because I remember having this conversation with my parents at the end of grammar school, secondary school, trying to decide what to do with my life.

And basically all I wanted to do was be a ski patroller, you know, have a dog and be a ski patroller. And my parents said, oh, well, darling, you know, doing medicine or being a doctor is a little bit like that.

You’re helping people. um And I sort of went, oh, okay, yes, maybe I should go to med school. And I can tell you it’s nothing like that. ah You know, you don’t really get to be outdoors, know, or hanging out with dogs too much when you’re a medic, especially in intensive care and cardiac surgery.

um But I’ve been sort of trying to get back to the mountains ever since, you know, with very success. Mm-hmm.

Steve House
Yeah, that’s, having been in professional ski patroller a couple of years of my life, um You know, my girlfriend at the time, she wouldn’t let me, we’d get paid every two weeks.

She wouldn’t let me see my paycheck because I would get so just i would get so i would get so bummed and worried.

Patrycja
Yeah.

Steve House
because But so I think you probably in some way, of many ways, made it made a good choice. I see your parents’ perspective, and I see your perspective, especially hanging out with dogs as a dog lover myself.

It’s great. Your career has taken you through seven different countries for your medical training. You’ve worked in Afghanistan, Uganda, Nepal. Was there a particular experience along that journey that crystallized your focus on high-altitude medicine?

Patrycja
I think there were two key factors. So once I grew up in communist Poland, and until the age of, you know, 91, I’m born 77, we couldn’t really leave or travel.
So once I could do it, I just couldn’t stop.

You know, I found it absolutely fascinating and a huge privilege to be able to experience different cultures.
um And I’ve, The other thing is I’ve always loved physiology and the understanding of how humans function.
And then, because I’ve always loved skiing, we don’t have high mountains in Poland. You know, the Tatras are not very high. But once I traveled in Nepal and sort of experienced altitude myself, I started looking into the incredible way our body adapts to what is a very hypoxic sort of critical illness level environment.
um That was it. You know, I was hooked, and I was very lucky to be offered a job in Machermo, which is the parallel trek to the Everest trek in the Gokyo region in the Himalaya.
And I spent a whole season working there as a doctor in the rescue station at 4,600, and seeing a lot of altitude medicine daily, you know, it was, it sort of kept me hooked and interested my whole life because it’s so variable and our understanding of it is so poor.

Steve House
yeah

Patrycja
It’s amazing to be able to sort of dig into it.

Steve House
I think that that that’s an important point and we completely concur that particularly our understanding of acclimatization and how the body responds to and adapts to high altitude is I think we’re really in the dark for the most part but we’re going to get it into that so what kind of things were you seeing and treating and what did those things teach you about how the body responds to altitude?

Patrycja
So I think that the, you know, there are many tracks coming through and I think the biggest surprise to me, I remember at the time was um the fact that often the fittest people were the sickest and that’s because they were pushing themselves too hard and they were used to driving themselves and they were not paying attention to how their bodies were trying to tell them to slow down.
So it was almost like almost the opposite of what I was expecting and very often people who are very fit, and not very fit or with medical conditions who are a bit more maybe cautious or maybe listen to their guides a little bit more, but were actually adopting really well.
So I think that was probably, for me, the main learning point. And also how scary it can be when things turn badly very, very quickly.

We’ve had, you know, quite a few patients, clients with severe high altitude cerebral oedema and pulmonary oedema. So also the the sort of acknowledgement that things can be very dangerous potentially, and it can happen quite quickly.

Steve House
Yeah, I’ve certainly seen that. And but I’ve been on both sides of that myself in my own experiences in the high mountains.

Patrycja
Yeah.

Steve House
Let’s get into this core topic of gas exchange. So, for those of us who haven’t thought about this much since high school biology, could you walk us through the journey of an oxygen molecule going from the air outside of the body to actually being used in a working muscle?
I mean, that’s a huge question. But I let’s go just like kind of the summary, and then we’ll go into like some of the some of the different steps along in the ah oxygen cascade.

Patrycja
So I think the first key thing to say is, and it’s something that I think we often forget, that Humans have adapted to life on the surface of Earth. um And, you know, if the composition of our atmosphere changes, ah we would not be able to survive. Okay, so we’re very finely tuned to the earth to the air that we’re breathing that’s around us.
Um, just the very basics, and I think without getting too political, if we can stick to kilopascals, which is the European way of doing pressure, just because it’s easier.

Steve House
Yeah, let’s use the metric system. It’s also the standard for science. So let’s let’s see let’s use the metric system.

Patrycja
So if you imagine the earth is the bowl in the middle, and then you’ve got the atmosphere, which is essentially a mixture of gases rotating. Well, it’s not rotating; the Earth is rotating, so most of the gases are rotating around the equator. It’s the fattest bit of the atmosphere. And as you get closer to space, the gas mixture gets thinner and thinner and thinner, and eventually there is no gas. There is just space, there is nothing, okay?

So the mixture of gases that’s sort of sitting on the Earth, the gravity holds it close to the Earth, exerts a certain partial pressure. And when we talk about gas exchange, we shouldn’t be talking percentages.

I often hear, oh, 21% and, you know, a third of that on Everest. The key thing here is partial pressure. So the partial pressure of gas is what keeps us alive.
And on average, when the weather is okay, it’s 100 kilopascals. That’s the total pressure of atmosphere. 21% it, so 21 kilopascals is oxygen okay so if we remember 21 kilopascals of oxygen from school and then the rest of it is primarily nitrogen and a bit of noble gases like xenon and so on but it’s essentially oxygen and nitrogen the other thing that always catches people out is there is no carbon dioxide in the earth in the air that we breathe okay so that’s why we need trees. Trees mop up the carbon dioxide and give us oxygen back. Okay. We give them carbon dioxide. They give us oxygen back. If we cut down all the trees apart from global warming and other, you know, like major issues, we will also rebreathe carbon dioxide, go into coma and all die. Okay. That’s another reason why we shouldn’t be cutting the forest.
So, when we take a breath, this mixture of gases essentially travels through to the 500 million bubbles called alveoli, which make up our lungs.
And if you take our lung out and stretch it, sort of alveolar thickness, so just one layer, it would be as big as a tennis court. You know, I always find that mind-boggling that you can have a huge surface area within our tiny, well, tiny bodies, right?

Steve House
Yeah.

Patrycja
And this is, I think, the first key thing. um And people often wonder, well, what’s the meaning of life? What’s the meaning of life? Well, the meaning of life is simple diffusion, okay?
So we only stay alive because of simple diffusion.

Steve House
And what is diffusion, and how does it relate to the MBLI?

Patrycja
Diffusion, essentially, it’s a very simple physical process where if you have a high partial pressure of gas on one side and low on the other, the gas will travel down the gradient and it will travel, you know, how fast and far it travels depend on what the gradient is, how thick the membrane is.
Okay. um And that’s pretty much it. So this little molecule of oxygen from atmosphere gets into the bubbles in our lungs and then travels farther, being carried by some hemoglobin into our tissues.
And then it travels to what’s called a mitochondrion. This is the engine of life in every cell. And it gets metabolized into ATP, which is the energy that keeps us alive.
Okay. It’s quite simple, it’s not terribly efficient and if the starting concentrate if the starting partial pressure of oxygen drops then there comes a point where there isn’t enough gradient to keep us alive essentially does that make sense

Steve House
Yeah, it does make sense. And so people think about climbers on Everest and using oxygen masks. um and then breathing ah more, like breathing a gas mixture that is higher concentration of oxygen.
And yet you also say it’s all pressure. So how do we understand the difference between like breathing a greater concentration of a gas at a low pressure, like what you have at the top of Everest, which is roughly a third of, I like to use, um 5,000 meters is half an atmosphere of pressure, roughly.

Patrycja
yep

Steve House
so so like and that’s maybe more relatable. Mont Blanc is almost 5,000 meters. It’s 4,800 meters. So, um, that’s about half an atmosphere of pressure compared to sea level. So how does that how does that work? How do we understand that?

Patrycja
So this is an excellent question. And um I would love to start using this more in that sort of altitude conversation.
So what you’re asking me right now is the difference the difference between normabaric hypoxia and hyperbaric hypoxia. Okay.

Steve House
Yeah. Mm-hmm.

Patrycja
So normabaric means normal atmospheric pressure. Okay. So let’s say at sea level,

Steve House
Normo, normal, baric pressure.

Patrycja
normabaric mm-hmm yeah so let’s say I am at sea level at home right now the pressure around me is 100 kilopascals okay 21 of it is oxygen so 21 kilopascals of oxygen if you put me in a hypoxic tent
or maybe use one of those masks people use for training, right?

Steve House
Mm-hmm.

Patrycja
Essentially what these devices do, they increase the nitrogen concentration, okay? So you’re dropping the concentration of oxygen. You get less percentage of oxygen, let’s say 17%, but the total pressure is the same, 100, right? So it’s 17 kilopascal. Now, when you go to altitude, let’s say, Let’s 5,000, let’s say Montblanc, more or less.
Your starting point is no longer 100 kilopascals; there’s 50 kilopascals, right? So 21%, so the mixture stays the same, but the kilopascals are less because 21% of 50 10, right?

Steve House
Yeah.
11 or 10 and a half.

Patrycja
And this is why. It’s not just supplementing oxygen if you go to altitude, because actually, what keeps the bubbles in our lungs splintered, it’s pressure. Okay, it’s atmospheric pressure. It’s not just supplementation with oxygen.
So when people climb Everest, when they breathe through the oxygen masks, okay, we increase the percentage of the mixture, so we add oxygen.
So you might be breathing 30% oxygen mixture effectively, but the atmospheric pressure is still lower. And that’s the one thing we can’t compensate for. So we’re exposing our lungs to lower pressures.
And that’s why, you know, for example, in hape high altitude pulmonary edema, it’s not the oxygen component as much that causes the flooding of the lungs. It’s the fact that the pressure that’s splinting the lung is not enough to sort of keep it open or keep the the fluid out.

Patrycja
Okay.

Steve House
And why can’t someone just like hold their breath and like increase the pressure in their lungs and pop all the vellio?

Patrycja
Well, they can, they can. It’s called auto-PEEP. Okay. And this is one of the methods, actually, there’s a really good paper about using it to treat early pulmonary edema at altitude. So essentially what you’re doing is you’re increasing your positive and expiratory pressure.
And it’s also, that is incredibly important in increasing the efficiency of your gas exchange at altitude, right? So when we’re walking at altitude, ascending, let’s say, we want to walk so slow that we can keep our respiratory rate, um you know, essentially normal.
That might not be possible, but as low as possible.
So, breathing in through the nose has many reasons for that. I can go into it, but breathing out through like a fish,
Sort of fish lips because that increases the positive end expiratory pressure in our lungs and it stops the lungs from collapsing.
It also makes us less likely to develop pulmonary edema and it helps the diffusion, simple diffusion in the lungs. So it helps the oxygen actually going into the ah circulation and then being picked up by hemoglobin.

Steve House
And this technique has actually been around for as long as I remember when I was a teenager, we I remember hearing about this and they would call it pressure breathing.
And even for people climbing like Mount Rainier in the United States, so about 4,000 meters, 4,300 meters, you know, that was the tip.
That was like when you purse your lips and create resistance when you breathe out. And that was called… the pressure breeding. i don’t think that we had like a good understanding of whether or not it worked.
I think that was one of those campfire conversations. Does that really do anything or not? I don’t think it does.

Patrycja
It does an awful lot.

Steve House
I think it does. um and and And now it’s kind of coming around to where we’re understanding that this may actually be a good idea.

Patrycja
So there are many physiological reasons for this. So I think one thing that is also really important and key to understand for people is that your performance and altitude.
So we’re talking about exercising in hypoxic conditions, right? At altitude.
That is not VO2 max-limited. Okay. So the, how fit your cardiovascular system is essentially doesn’t, does not determine how you perform at altitude.
So at altitude, any exercise is diffusion limited. So it’s the mechanics and the state of your lung, um, that is key to how you perform.
That’s going to limit the oxygen delivery. And if you think about it, every time we take a breath, we take about 450 mils of air mixture in, okay?
150 of it, it’s sort of wasted the the respiratory pathway. So that’s not gas exchange. It’s before you get it before it gets to the 500 million bubbles, okay, where it can go into the blood.

Steve House
Yeah, it’s the air that’s occupying your mouth and, you know, trachea and so on.

Patrycja
Yeah. Yeah.

Steve House
Yeah.

Patrycja
So if you want to be efficient in diffusing, the slower you breathe, the better, because then you don’t waste 150 mils every time you take a breath.

Patrycja
You’re much better off expanding your lungs more because then you only lose the 150 mils once.

Steve House
Hmm.

Patrycja
Do you see what I mean? So taking bigger tidal breaths is better.
And then the other thing that’s key is, so the red cells,
take about 0.25 seconds to get loaded with oxygen in our lungs. But they stay there for about 0.75 seconds.
And at altitude, you need a way longer time for equilibration.

Steve House
Oh, interesting.

Patrycja
So actually, big breaths expanding our lungs and then holding and slowing your heart rate down So the cells, you know, can sort of use the 0.75 seconds to pick up oxygen is much better.
So it’s almost like the opposite of people tend to do. People tend to push hyperventilate because they feel short of breath. You need to essentially slow your breathing down and slow your heart rate down as much as you can to make it more efficient.

Steve House
Yeah, that that tracks with, you know, even when I ask a mountain guide on Denali or places we would always be telling people to do like belly breathing, you know, move your belly out, get a really fill the chest, you’ll fill the upper part of the chest, like really fill the lungs, make those big, deep tidal breaths is your term.
um Let’s go back a little bit. And so now the oxygen molecule, let’s talk about this. let’s say, moment, 0.25 seconds, or however long it is, where the oxygen molecule that’s been pulled into the villi, and now it’s getting transported to the red blood cell. Let’s talk about that, like little, well, not so little, that very important interaction and exactly how that happens, and what gets in the way of it, and what the limitations are there.

Patrycja
So I think um oxygen cascade, okay? So how the oxygen sort of drops down from atmospheric partial pressure all the way to the mitochondrion. So every time we take a breath, and if we breathe through the nose, which is the most efficient way, the nose does two things. It clears the gas mixture, so it stops you from soiling your alveoli, so the little bubbles where it all happens.
In the nose and then in the pharynx, so the back of our throat, the air is also warmed up to 36 degrees. And what’s added to the mixture is humidity, so water vapor. So it becomes 100% humidify.
That’s key for the sort of alveoli well-being without humidification and the same temperature diffusion is very difficult. So again, when walking, it’s really important to not be mouth breathing.
because you then expose your alveoli to dirty air, cold air, and you lose a lot of energy, re-warming the gas all the time. So this is where the atrium masks come in or having a bath on your face and making sure that you’re always breathing, sort of you keeping the warmth and the humidification in your airways. You’re not using energy to do it every time.
um And then the air travels sort of through the trachea bronchi down into the alveoli. Now, what happens in the alveoli is we’ve got to have space for the water vapor. That’s about five kilopascals. Okay.
And also carbon dioxide shows up, right?
Because we’re the ones, we you know, mammals are the ones who are producing carbon dioxide. So the carbon dioxide comes out of the blood and goes into the alveoli. And there is something called Boyle’s Law. ah Divers will be very familiar with it. But essentially, it says that the total pressure of any gas mixture is constant, right? So if you suddenly have five kilopascals of carbon dioxide and five kilopascals of water vapor in the alveoli, there’s less space for the other gases. So that’s where the first major drop in oxygen happens and it drops about by about a third. So the oxygen doesn’t have as much space, right?
And this is key for altitude adaptation. So the main thing that happens when we go to altitude, where it’s suddenly hypoxic, we will be hyperventilating like crazy.
And we’re hyper-ventilating because we want to get rid of all of our carbon dioxide to make more space in the alveoli for the oxygen, so it has a bit more partial pressure to actually go through.
So it generates enough partial pressure to actually bind with hemoglobin. Okay?

Steve House
Can I pause you right there? Because I want to be clear. Can you explain why the hyperventilation you just experienced versus what you just said had these deep tidal breaths?
So make sure that people aren’t getting confused on this point because I think it can be confusing.

Patrycja
Well, it is very difficult. So we will all be hyperventilating. um And I just told you you should be taking very slow breaths, right?
Or um it’s very difficult to do.

Steve House
Right.

Patrycja
So um there is also a difference in how our respiration or breathing is controlled. So in hypoxic environment, which is high altitude, hypoxia drives hyperventilation. Okay. So that will be something that will be very difficult for you to control. There is a degree of ah conscious control over ventilation, but it is quite difficult. And you, when you go to altitude, you will hyperventilate and you essentially keep your CO2 level at much lower levels and you’ll reset your control to a lower levels of CO2.
But despite that, if you can add the deep breathing, so using of accessory muscles and splinting. So, you know, often if you’re walking with a backpack, if you put your arms on the belt, because that allows you to fix the frame and then use your additional muscles, not just your diaphragm and your intercostals to breathe, that helps you achieve sort of higher volumes.

Steve House
So put your hands on your on the hip belt of your backpack to sort of support your…

Patrycja
Yeah, do this.

Steve House
Yeah, okay.

Patrycja
Yeah. Because if you fix this frame here, you can use ah your interscalings and your sternocleid muscles, which are up here to aid your ventilation, because what you want to do is expand your lungs does as much as you can. So your diaphragm will move by about 10 centimetres maximally. But you can also lift your sternum and your clavicles if you use additional respiratory muscles. And what helps that is you essentially need to fix your arms to have a fixed frame to be able to do that.

Steve House
Interesting. Super helpful. Okay. So now, um, I understand. So I think that’s clear now, like, I mean, you, the goal is to take deep tidal breaths, but because there’s, you know, a buildup of a, correct me if I’m wrong, but because there’s a buildup of carbon dioxide, you’re triggered to like exhale that. And that sort of triggers the hyperventilation. Is that my understanding correct?

Patrycja
Yeah, so I think the the… Okay, this might be an easy way of understanding it. So hyperventilation essentially means increasing your minute volume.
Okay, your minute volume, so how much you breathe for a minute, essentially is your respiratory rate times the volume of each breath, which is the tidal volume.
Okay, so you have two ways of doing it, right? You can either do this…[quick shallow breaths]which is not very good at altitude because it’s shallow.
And it will increase your heart rate, your breathing through the mouth. So you use a lot of energy to warm up and so on. Or you can try consciously to take very, very deep breaths. So then you sort of achieve the same increase in minute volume.
By moving bigger volumes rather than increasing the rates.
Do you know what I mean? That’s a way more efficient way of achieving hyperventilation.
I think most lay people, when they, you know, hear hyperventilation, they assume it’s fast breathing. It isn’t. You can hyperventilate by increasing your minute, total minute volume.

Steve House
Got it. Okay. Yeah. That was my assumption. That was my confusion on this term. Okay. So,
like take us take us down to the red blood cell level where this you know the oxygen molecules diffuse across the aveli, why is it attracted to, why is it diffused?
Like, what is that like, negative pressure on the other side of the aveli in the blood, that it’s going from the air into the, to bond with the red blood cell?
What exactly makes that happen?

Patrycja
um well I mean, it’s it’s the, i you know, Newton’s apple, right? Gravity. Can’t do anything about that. Okay.
Physics.

Steve House
Right.

Patrycja
Everything is physics. um

Steve House
Yeah.

Patrycja
If you have a higher concentration of something on one side and lower on the other, it will travel. um It’s not more complicated than that.

Steve House
I understand that, but if it’s if it’s traveling from ah from a gaseous form into ah into the to bond with a red blood cell, like well

Patrycja
Yeah.

Steve House
What is there, what is the attraction? What is the, what is creating the slope? It’s not intuitive to me that I going from a gas into a liquid would create that negative slope.

Patrycja
Okay, so any gas mix, any partial pressure of gas above the liquid, will make some of it dissolve in the liquid, okay? It depends on how soluble the gas is.
And the interesting thing is that CO2 is 20 times more soluble, carbon dioxide is 20 times more soluble than oxygen, for example.
Actually, the transfer of CO2 is way easier, way less sort of pressure gradient consuming compared to oxygen. Now, the oxygen is super interesting because we have hemoglobin, which is this genius sort of molecule, right? Um, it’s got four; each molecule binds four molecules of oxygen. It’s got this special heme structure. It needs iron to work well, but essentially, hemoglobin is like this Maserati for oxygen transfer. Okay. It’s highly, highly attractive to oxygen. And when you exert hemoglobin molecule to partial pressure of dissolved O2 in the plasma or in the blood, which depends on the alveoli partial pressure of oxygen, it will change its shape and mop up all the oxygen molecules it can.
Okay And how much hemoglobin mops up depends on what the partial pressure of oxygen is in your blood, which depends on the air mixture that you’re breathing and how much is in the alveoli.
And the other thing that’s incredible about hemoglobin is that it can shift its affinity for 02 So we can adapt and sort of make itself more sensitive to oxygen at lower levels.
pressure, you know, at lower partial pressures. And that’s where a lot of the adaptation to hypoxia and altitude comes in, and it does it by various things. So let’s say if you’re, if our CO2 levels are increased or we’re very acidotic because we’ve just exercised, it will make itself more sensitive to take more oxygen because it’s getting all these signals that we might need more. It also develops this 2,3 DPG.
DPG, which is a special cocktail that makes it more sensitive to oxygen. So a lot of the hypoxic training or intermittent hypoxic exposure in exercise or when people bring themselves just to the anaerobic threshold of exercise, it will be essentially sort of stimulating the hemoglobin A production, so hyperproduction, but also making the hemoglobin a bit more sensitive or a bit more keen to take oxygen at lower so partial pressures.
Okay, and most of the oxygen that’s in our body at any given time is bound to hemoglobin. So we’re talking 80%, 90% of oxygen is transported with hemoglobin. If we don’t have hemoglobin, we cannot stay alive. So just the dissolved oxygen in blood is not enough to keep us alive. okay That’s why hemoglobin is key
Um to to our survival and people with low hemoglobin levels. so you know, acute hemorrhage ah or a very severe iron deficiency, you know, will struggle with hypoxic or critical environment or a critical illness. And then the hemoglobin travels through the circulation, right? So six liters per minute, we’re pumping blood on average. That then goes to the tissues, to the capillaries,
And the environment in the capillaries is such that the hemoglobin is more keen to get rid of oxygen. So it sort of dumps oxygen. And then again, simple diffusion is everything. Okay, so whether or not the single mitochondrion that you need in your big toe will get oxygen depends in the peripheries on simple diffusion. And the key factor here is how dense your capillary network is, because that determines how far the oxygen has to travel, you know, from the capillary to the mitochondrion in the single cell. And, you know, professional athletes or people who are very, you know, who train a lot, a lot of their adaptation will be increasing the density of the capillary network, essentially. And then in the mitochondria,
um some of us are… just better at adopting to hypoxic conditions. I’m sorry, we can’t control. I know you’re training people.

Steve House
There’s a genetic component.
No, I mean, it’s 100% true, yeah.

Patrycja
There is a huge genetic component where some of us are less likely to die if we’re critically ill with shock in intensive care.
So we’re just more able to deal with what is, you know, the hypoxic sort of challenge to our organism. And a very interesting point in the mitochondrion is so-called Pasteur’s point. So if your partial pressure of oxygen drops to below 0.3 kilopascal in the mitochondria, that’s when you go into anaerobic exercise. Okay. So that’s the sort of cutoff point. So maybe like just one more thing, and I’ll try not to make it too complicated, but essentially there are these things called hypoxia-inducible factors. There are quite a few of them. And we have very little understanding of what they actually do and how they work. But um they trigger an expression of over 200 genes in our body. i mean, that’s how complex adaptation to. hypoxic stimuli is, okay, it’s incredibly complicated.

Steve House
Yeah. Before we go into hypoxic inducible factors, want to back up and kind of summarize some key points for people. One is that the oxygen is diffusing from the gas inside the viuli into the blood before it is bound to the hemoglobin, which is part of the red blood cell.

Patrycja
Yeah

Steve House
It’s… it’s always been my mental model that somehow the oxygen went like, I wasn’t thinking about the gas trans, um, uh, uh, transfusing.

Steve House
What’s the right word here? Um,

Patrycja
Diffusing, diffusing.

Steve House
Diffusing, sorry.

Patrycja
Mm-hmm.

Steve House
I wasn’t thinking about the oxygen diffusing into a liquid. and just thinking the blood is a liquid. So that also brings up the point of how vital hydration is and what a big role hydration can play because if we get dehydrated, especially on the more extreme ends, our blood volume is affected and the blood becomes less ah less liquid, more viscous, more thick.
And that also affects the ability of the oxygen molecule to diffuse across that barrier into the liquid in order to get picked up by the hemoglobin.
Is that correct?

Patrycja
That is correct. And it’s um, um, incredibly important. So there is a whole science of flow called rheology. And it has to do with how efficient flow is. And it’s that’s incredibly important at altitude because um we get dehydrated for many reasons, um or um maybe not just dehydrated, how thick our blood is increases a lot at altitude. It’s because we’re producing a lot of new red blood cells. So our blood becomes more dense But there is also a point where if you compare blood flow to a very busy, you know, like an American highway, right? You’ve got five lanes and imagine the red cells are cars, right? There comes a point if it gets too busy, it gets very inefficient, it gets slow. So you need to have, it’s called a hematocrit, which is sort of, it’s the proportion of ah Cells versus plasma in the blood. um You don’t want it to be too high because then it’s too slow to thick. It increases the risk of clots as well. And if you think about flow through the pulmonary capillaries, essentially, pulmonary capillaries are wide enough to accommodate one red cell. So you need to have enough sort of, you know, and it needs to be viscous so it can pass through the capillaries without getting stuck, right? Ah, our bodies are amazing at sort of regulating this, but yes, hydration is key. And this is where I would say, you know, people who tend to use acetazolamide or Diamox, what Diamox essentially does is bicarbonate wasting. So it makes you wee out bicarbonate, but you lose a lot of fluid with it because you need fluid waste you know what to wee the bicarbonate out so this is where if you’re using it uh you know it will help your adaptation but you sort of need to compensate for for for you know for being dehydrated

Steve House
Absolutely. Absolutely.

Patrycja
Can I just add one more thing because I also think it’s relevant, so you’re at, the atmospheric pressure also varies a lot depending on where you are on planet Earth.
So because the sort of at the the the atmosphere, because of rotation, is the thickest around the equator, that’s why we can climb Everest without oxygen. okay So the closer you are to the poles, the atmosphere is thinner.
okay And that makes a bit different. So people tend to think… oh, well, wincent Vincent is not so high or Denali is not so high, but get quite sick. That’s because there is a little bit of atmosphere above us when we’re closer to the poles. And also, seasons can make a big difference. So, you know, the spring and summer in the Himalaya is much better because atmospheric pressures tend to be higher, on average, than in the winter. And when you’re operating within margins, you know, that like that might make a difference.

Steve House
Yeah, 100%. Okay, so um let’s talk about red blood cells and hemoglobin a little bit more. There’s this perception that the body’s ability to create and generate new red blood cells and mature them and get the is a major part of acclimatization. This is what we’re all taught. But we also are taught that this takes a long time, that, you know, from the erythropoietin in the being, which stimulates the birth or the generation of new red blood cells to the red blood cell being, quote unquote, mature.
And I would like you to explain what that means to us. is like so six weeks, you know, and at most expeditions are only six weeks long. So we’re going to go into sort of pre-acclimatization strategies and some of that.
And I think that this is important to lay this foundation for like how that process works, how important are red blood cells, what conditions should we create within our bodies in terms of nutrition and hydration and exercise to to make sure that we are producing the healthiest highest quality, most abundant red blood cells.
And is there an upper limit like where we have too many red blood cells and is that possible without ah going going into you know using strong medical medications that are are aren usually not accessible or legal?

Patrycja
Well, this is a this is a huge subject.

Steve House
Yeah.

Patrycja
um So I think the first thing I would say is um
If there’s one blood test that one should have before sort of planning any major expedition, I think it’s a full blood count, including you know hemoglobins, ferritin, transferrin, and iron studies because it’s a simple thing to do and it would be really silly to to try to generate your own red cells if you don’t have enough iron.
Okay, so there are many there might be people who, let’s say, have normal hemoglobin levels but the iron stores are depleted. So they’re not depleted enough to show in the hemoglobin level.
But when you suddenly have a huge stimulus to produce lots of more cells, you need a lot of sort of iron stored in your body to to be able to do that, to be able to generate them. and So it’s always worth checking that.
In terms of increasing your HB levels, the best way to do it is for your body to do it on its own. Because the cells that you produce then are of highest quality.
So, um, and a lot of it has to do with, um, so sort of intermittent chronic hypoxia is a really good stimulus for your body to produce well-functioning cells that are sort of sensitive to O2 and will work better at altitude. So this is where you know either sleeping in a hypoxic tense or intermittent hypoxic training or training where you just bringing yourself into the anaerobic threshold essentially has the same effect will be will be very good.

Steve House
Mm-hmm.

Patrycja
Traveling to altitude frequently also does the trick. um Now, any pharmacological fixes, you know they always sound great.
But the issue is that ah the cells that are produced might not be ah of good quality and transfusing cells essentially gives you sort of fairly average red blood cells because the way we store them makes them deplete of 2, 3 dpg and make them work not very well. So if you compare oxygen capacity, let’s say of transfusers versus cells that we grew ourselves, and it’s you know it’s like 80%. So essentially, there are no quick fixes.

Steve House
Mm-hmm, mm-hmm. And I want to sort of reiterate just from my own experience some of the things that you said and how those manifest. And one of the things is
People often get really discouraged when they first go to altitude, and they think, Oh, I’m not good at altitude. I don’t acclimatize. Well, I can’t do that. And they, they check out, they do something else. And I, first time I went to 5,000 meters, I got sick as a dog.
And was like, yeah really sick, really like almost had hard time walking to get myself down. But I just also noticed through myself, the more I went to altitude, the better my body got, it became at acclimatizing.
And I noticed that with other people that I would climb with that were more experienced than I was as a young climber and be like, wow, how come they’re so fast at altitude, et cetera, et cetera.
And it’s like, that is earned, that’s part of the process of becoming an altitude, high altitude mountaineer, a mountaineer in general is you’re just going consistently as you said intermittent hypoxic exposure you’re repeatedly asking your body to do something it’s just like the training effect like we’re asking our body to build a capacity to do something like move uphill for a sustained amount of time and it will build that capacity we can’t expect it to build a capacity that it’s never been asked for before. It’s like giving somebody a test on on a subject they haven’t studied, they’re they’re going to fail, right? So I think that that’s ah really important. And I think it connects back to the the the philosophy ah behind a pill athlete, which is you know that this is not um these sports and these activities being in the mountains.
It’s not something we do like you know one week a year. It’s part of our lives. It’s part of our our whole trajectory of our life of of becoming a person that can do these things like climb high mountains.
And I think that that’s super important.
And I also want to get into a little bit something that you said, because I’ve seen some of the, from Dr. Robert Browning, we’ve discussed this briefly offline, who has been doing these studies, which he hasn’t been able to publish yet because they’re ongoing, just just the sheer scale of the research the way that the human genome reacts to high altitude is is really mind boggling.

Patrycja
Mm-hmm. Mm-hmm.

Steve House
It’s like you said, it’s it’s hundreds of switches on our genome are either up or down regulated. by a simple exposure to high altitude.
And a lot of these switches, we don’t even know what they do yet, right?
So there’s all kinds of things. What does that make you feel as a physiologist and as a physician, are you excited at the prospect of how much there is yet to know and understand about how we can better acclimatize? And what how do you think about that, where we are on the sort of the evolution of human knowledge around this topic?

Patrycja
Well, it makes me feel excited, I guess. You know, it’s, um you never stop learning, right? And I think all the methods that we currently have to help people adapt are fairly crude.
um I think a lot of the work will be probably about individualizing the process because people react in such different ways. You know, they there are um there are people where you recommend certain things, but it might be the opposite of what they need. so because the process is so complex and um and, but I also think it opens huge, new opportunities. And I think the key thing for me is that there is so much crossover in what I do in my daily work. So essentially, most of my patients, you know, are trying to deal with critical levels of hypoxia in one way or the other. And that is very similar to being at altitude in a way. So finding new ways of being able to support people is, is very, very exciting. And I think Just going back to what you said, how awful how awful you felt at altitude the first time around.
I really wish we could relabel acute mountain sickness, um you know, adaptation, altitude adaptation syndrome, because it does my head in, you know, sickness suggests that A, there’s a pathological process, something you need to be worried and scared worried about scared of and a bug, you know, a bacteria, virus, oh God, I have AMS, I have to take drugs, please help me. You know, all the symptoms that you describe are essentially physiological symptoms of your body gradually slowly adapting to it right it’s only the escalation that’s a problem so you know when you’ve got a little bit of a headache and you feel crap and you don’t want to eat and you haven’t slept well that’s a Lake Louise score of let’s say you know not so high that’s altitude adaptation syndrome. And that’s what everyone, 80% of people, will have. And it’s completely normal. It’s just your body telling you, Ooh, you know, this is not the environment I’m used to. I feel a little bit short of oxygen here, but actually i can cope with it. Give me time. Let’s take it slowly and we will be okay. um Yeah, I really think we should sort of try to change the way we think about it.

Steve House
I like that a lot. I like that a lot. I want skirt in this conversation because there’s so much else to talk about the idea the discussion around altitude illness and talk more about it stay focused on like kind of gas exchange idea.
So to go back in summary, the oxygen is binded to the hemoglobin. Hemoglobin is part of a red blood cell.
The EPO, the erythropoitin, is the key trigger that tells our body to increase the red blood cell count. and we need to have good iron stores on board before we start building correct new red blood cells. Okay, we got that. everybody or i’ve I’ve summarized those and i’m and I’m on track. Now I would like to shift as I think this is a good segue because we talked about like you talked about how we should reframe mild what we currently call acute mountain sickness to um altitude adaptation

Patrycja
Syndrome.

Steve House
syndrome or process. and so a lot, we we can agree that frequent bouts, whether it’s in the Alps or the Cascades, or you live in Colorado, or, you know, those places you’re going to have access, even California to a certain extent, you’re going to have access to 4,000 meters, let’s say.
But if you live in Poland, or you live in the UK, or you live in New York, or ah Florida, you don’t have access to that.
You live I’ve had the challenge and the and pleasure to coach athletes who are living in Mexico City and they had ample opportunity to get this intermittent exposure to altitude.
But also I’ve had athletes, one guy last I worked with last year, he climbed K2 without supplemental oxygen. He lived in Singapore. He never went above the top, you know, the highest altitude he reached was the top of a building, which was probably 100 meters above sea level.
So, a lot of people are bound by their location that’s far from real altitude. So let’s talk about some of the hypoxic training methods that might help us at low altitudes.
And there’s a few different ones. You want to kind of summarize what some of those different modalities, potential modalities are. And maybe we need to come back to that idea that you touched on earlier, of normabaric hypoxic conditioning versus hypobaric hypoxia.

I mean, I hope I’m not going to say anything too controversial. um I think there are many, many modalities that we can use None of them as good as are as good as going to altitude. And the reason for that is that essentially the the way we can generate hypoxia at sea level is by adding more nitrogen to the air that we’re breathing. So we are still at normal barracks or normal atmospheric pressure. We just have the oxygen, the the gas mixture has less oxygen in it.

Steve House
Isn’t it kind of the opposite of like using an oxygen mask and breathing a higher concentration of oxygen?
Having the oxygen that’s on Everest, you’re breathing through an oxygen mask, and you’re breathing 30%.

Patrycja
It is exactly the opposite.

Steve House
And that’s displacing nitrogen. And now we’re taking nitrogen and displacing the oxygen molecule.

Steve House
So it’s the the opposite of that.

Patrycja
It is essentially the opposite of that. However, you know, if you look at what you can modify before you travel to altitude, you know, if you look at the EPO response and the making of the new sales, as you said before, that takes most of the time. OK, so that’s the thing that’s really worth doing before you go, because you are sort of starting the process that you would be having at altitude anyway. You’re just starting it sooner.
And red cells tend to live for 21 days. So a lot of it is about timing as well. um And this where, you know, the main modalities we have essentially is sleeping in hypoxic tents.
So you either have a tent on your head, or you have a tent that your whole mattress is in.
Before going to Everest this year, I, you know, I slept in a hypoxic tent. ah I absolutely loved it because there’s a lot of white noise. There’s the constant buzzing. It’s nice and warm.
Some people hate it because it’s too loud. So again, you know, this, how you cope with this depends very much on. whether or not you get on with the technique. But I think here we say that you need to sleep in it for at least 250 hours. So, you know, we’re talking four, six weeks of of eight hours of of sleeping in a hypoxic tent. And you can go up to as high as 6,300 in these tents. Okay. So you monitor your sat overnight um and it works very well for some people.
The other thing you can do is you can have short hypoxic bursts at rest.
I think most of us feel that um it is much better to do hypoxic bursts exercise, that that tends to work better in stimulating EPO than just doing it at rest. So that’s the classic, you’re on a treadmill and you have a nitrogenator next to you.
and you have a mask and then you breathe, you know, again, ah mixture with higher nitrogen concentration and all these things, essentially what what it does, it it stimulates the hifs, so hypoxia-introducible factors, and it mostly stimulates your EPO into generating your own red cells. Many athletes I know or work with, sort of can sense it when they’re getting themselves to that point. if you think about it, you know, if you train and you bring yourself into the anaerobic threshold, but not so far that you get a lot of lactic acid. So, you know, you don’t, you will know more about this than I do, but essentially people can sense when they just get to that point and they do it intermittently many times, you know, that’s sort of similar to breathing a hypoxic mixture.
Um, so, you know, Andre who I work with, uh, you know, he just has this incredible innate intuitive ability to know when he’s hitting that point and he will be doing it intermittently and actually, you know, doesn’t use a tent, but essentially achieves the same thing, right? It’s the continuous sort of hypoxic inducible factor stimulation. uh, so, you know, all of these are great. Um, and I’m sure. With more research there will be more things that we might be able to do to prepare better to climb safer essentially.

Steve House
And this is something that we’ve worked with at Appalachy. We have a program that runs parallel to our existing coaching where we will do the hypoxic, normabaric hypoxic adaptations. And we’ve done it with people in tents, as you described, with the and interestingly, like I had an athlete that I worked with on this couple of years ago, Climb k two also without supplemental oxygen. We couldn’t get a tent to Australia because they don’t have a distributor there.
So we only use the exercise ah induced, you know, with ah with a nitrogenator on on the stationary bike and also used a
breathing or restricted breathing mass on some of his other workouts. And it seemed to work really well. And he he did really, really well in the mountains. So there is certainly something. It takes a lot more effort than for those that live in the mountains and have the ability to go up to the top of Mont Blanc or whatever easily. That’s relatively easy. That’s always always better, as you said, but it’s it’s remarkably effective. I
have to say, like I’ve said this on the podcast here before where I first tried it in 2001, believe. It was 2003 for an expedition to Mashabrum, which is about 7,800 meters. for an expedition to go to Masherro, which is about some thousand eight hundred, and it didn’t feel like it worked. Like it was a lot of work ah to do the thing. I was in the tent for a couple, like eight weeks.
I think that back then the problem was it took us 10 days to get to base camp. It’s just like, by the time I got to base camp, I hadn’t been in the tent for over two weeks. You know, I’ve been traveling, I’ve been and buying potatoes in the market.
I’ve been doing all the things that you know, have to, had to do for expeditions, especially a small, low-budget expedition back then.
And by the time I got to base camp, there was probably not much of the acclimatization left, and it didn’t feel like I was any better than I felt like I was the same. And so I was for a long time for that reason, kind of like, you know, dismissive of the technique.
But I think one thing that’s happened is we’ve gotten much better at understanding, like you said, how many hours do we need of these different stimuli?
What are we actually doing? And so now I want you to talk about the hypoxic inducible factors and what those are and what we understand about them because I,
I think we can agree there’s probably a bunch of things going on that we don’t understand, but there are some good ones that we’ve understood. And we and we we’ve come a long way, I’d say, in the last…
For sure 10 years, but even in the last three years, I feel like in the in our sort of community of practitioners in this space, we’ve come a long way in understanding what these hypoxic inducible factors, the HIFs are and how we are affecting them.
What this what what what stimulus we’re giving the body through the the let’s say fake altitude or the stimulated altitude and what reaction we’re getting out and how highly individual it is.
So let’s talk about that.

Patrycja
There are people in the you know, in the community, who might have chronic illness, whether it’s heart failure, whether it’s severe, you know, chronic obstructive pulmonary disease, pulmonary hypertension. So there, you know, there are people out there who are able to adopt and sort of survive. In conditions or, you know, so on the edge in terms of where they are with their oxygen delivery, that if you, if you know, if you put you and me in that situation acutely, we would just die, right?
So, um and that’s achieved through the sort of chronic stimulation or chronic hypoxia and all the different adaptations that happen that allow our body to function. And that’s why we can function at high altitude. Aou know, apart from what we’ve talked about, which is the hemoglobin, right, that’s that’s ah a really… You know, a big part of it, but also the way, let’s say, even if you look at how, um, our ventilation and, uh, the function of our cardiovascular system is controlled, that sort of learns and adapts as well. So, you know, you, um, let me just find a good example.
I think what I’m trying to say is that it’s, you know, there are so many levels at which they work that it’s almost impossible to explain it.

Steve House
Is there like a, are there layers?
Is there like a base that like is a mostly hemoglobin and then the next thing is like, I don’t know, like, um, ah blood acidity, a pH, ah like, are there, like, there a way you can break it into layers

Patrycja
I mean you’ll be adapting you’re sort of adapting at every level so you’re you know the way your central nervous system controls your respiration and your cardiovascular system sort of resets, right? So it’s almost like AI, it learns to um sort of act to different triggers, right? So let’s say if you.
You have very high CO2 levels because your lungs are not very good, then the sort of acidity of your brain changes, but your brain will learn to sort of reset its control to different pH levels and at different CO2 levels. Um, it will, ah, the way your lungs work will adapt. But I think that the other, you know, key thing is that, um for example, your mitochondria will reset for a different, like a different level, they can learn to function in a more hypoxic environment. We don’t have any good ways of measuring this. This is maybe the, you know, the other important thing is like that EPO you can measure, hemoglobin you can measure, but yeah, we don’t really have a good way of measuring what HIFs do.

Steve House
Mmm.

Patrycja
So, like, you can use lactate thresholds, but that’s a very crude way of measuring it.

Steve House
There’s no measurement for the efficiency of the mitochondria’s use of oxygen in a hypoxic environment.
Or in a non-hypoxic environment for that matter, right? Like there’s no there’s no chest strap that we can put on that would measure that.

Patrycja
Oh, the other thing that I think is important is how much oxygen we extract.
Because people… i don’t think people know that there is a lot of oxygen in the venous blood as well. So we cannot extract more than 50%.

Steve House
Hmm, mm-hmm.

Patrycja
As in so the hemoglobin is always, there’s always some oxygen on hemoglobin.

Steve House
Yeah. Yeah. And that’s interesting, right? I mean, I think that when I learned was a kid and learned CPR, that was one of my first questions. Like, how does breathing into this person help them give them oxygen if I already pulled all the oxygen out of the air?

Patrycja
It doesn’t.

Steve House
But it doesn’t, right?

Steve House
Like, we’re we’re actually pretty…

Patrycja
That’s why we don’t do it anymore. Yeah, yeah, yeah.

Steve House
okay

Patrycja
We just do chest compressions because you have enough, you still have some, unless it’s, you know, avalanche burial, because the asphyxia might be a big part of it. So you tend to give rescue breaths.

Steve House
Oh, okay. Well, so I’m so out of date on all my medical stuff. um

So, look yeah, look why don’t you walk us through… The oxygen extraction and how we measure that. And, you know, these people are obsessed with their O2 sat measurements and they all, everyone’s carrying a little O2 sat measure around the neck these days or on their watch.
Let’s talk about that. Tell me about oxygen extraction and how that works.

Patrycja
So as we said before, most oxygen content or carrying capacity is determined by how much hemoglobin you have and how well that hemoglobin functions, how healthy your red cells are, essentially.

Steve House
Yeah.

Patrycja
The interesting thing is that, so if you have enough partial pressure of oxygen in the plasma, then 100% of your hemoglobin gets saturated, right?
So that means that all the binding sites on hemoglobin are saturated with oxygen. So that’s oxygen saturation.
And this is what we often measure: what our watches measure is oxygen saturation. Now, the way that’s measured, it’s by shining an infrared light through tissues and so oxygen saturated with chemoglobin absorbs some of the red ah infrared lights.
So then, you know, the clever computer calculates sort of how much of the infrared got absorbed and it gives you a fraction. So oxygen saturation is a fraction.
And what most people don’t know is that venous blood also carries a lot of oxygen. So in normal conditions at rest, we only extract about 25% of oxygen that’s bound to hemoglobin.
So your venous saturation is 75.

Steve House
And the venous blood is the blood returning to the heart and lungs.

Patrycja
Returning to the lungs, yeah, so the the the that’s the blood that’s sort of given the oxygen to the tissues, to the mitochondria, and it’s returning to the lungs to pick up more.
And um the way we can tell how sick people are or how critically challenged from the hypoxia point of view they are is by testing venous saturation. So maximum human body can extract in the peripheries in the tissue is 50%. So venous saturation of 50% means you’ve just run a marathon, climbed really hard, or you’re critically ill, essentially.
Okay.

Steve House
But the O2 sat meters are measuring venous saturation or arterial saturation?

Patrycja
Arterial. They’re very clever. So they can tell the difference between a pulsatile signal and a constant signal. So venous sats have a constant signal because it’s a non-pulsatile flow, and arterial sats have a pulsatile flow.
Okay. So, um, the measuring device can tell the difference. So it only tells you the saturation of the pulsatile flow. So the arterial saturation. Now, important to understand about pulse oximeters is that there are huge limitations to what they measure.
So let’s say if you have one on your finger, that does not give you the full body picture. It gives you, you know, the O2 saturation in that finger.
Okay. So if your blood flow is not good, let’s say you’re cold, you’re dehydrated, you’re you know, you might have a little thrombus here, then the reading that you’re getting might not actually represent what’s happening in the body.
And that’s where the sort of holistic assessment, how the climber is, or your patient is, is really, really important. And often, I see it very often that people get very hyper-focused on one number and you know, a question that I get often is like, well, what O2SAT would you be worried? And I’m like, I i can’t answer that. I mean, I would look at, you know, is someone conscious? Do they look like, does it work? Like they’re working really hard. Their work of breathing is through the roof. You know, do they make sense? Either tachycardic, what’s their blood pressure? What are the other things doing? You know, I wouldn’t just sort of say based on this one number that someone is sick or not sick. It’s more about trends. Mm-hmm.

Steve House
If someone’s at ah at, I don’t know, Everest Base Camp and they or Camp 3 for that matter, and they have a certain O2 sat compared to, you know, and it’s, let’s say, relative to their other climbers, it’s higher or lower. Does that correlate to someone’s acclimatization status? Is someone acclimatizing better or acclimatizing worse? Or is it again, just one data point among many?

Patrycja
It’s one data point among many, which has, you know, a fair amount of measurement error.
And I think this is where having experienced guides is so impulsioned. I mean, I often say you don’t need a doctor on an expedition. You just need an incredibly experienced guide who can tell that someone’s cognitive function is worse.
They’re starting to trip, they’re sort of starting to lean, and you know, against walls, maybe losing coordination a little bit, right? And then you’ve got that number and it’s worrying.

Steve House
When people what is there a big difference between the different devices? Because you can order these things on Amazon or something for $10 these days.
Are there medical grade? Are there non-medical grade? is the is the um pulse oximeter on your Apple watch work as well as something on your finger. I mean, understanding that it’s limited to measuring the O2 sat at that point of measurement, whether it’s your finger or your wrist, but is that something that people need to be concerned about in terms of selecting a device?

Patrycja
I think most of them, I mean, it’s sort of, it’s been around for such a long time, and it’s so simple that most of them work very well. I don’t think you need, you know, um, you need anything too sophisticated. I mean, they are helpful, I think, if people use O2SATS to guide their adaptation process. I tend to say, you know, please take the measurement at the same time of day in a similar sort of circumstances. Let’s say after breakfast in the morning, when you’re sitting in the warm tent, and you’re at rest, and then compare it day to day. So you have comparable trends, you know, do it along the Lake Louise score.
And let’s say what’s your heart rate variability, which is probably a better marker of how stressed your body is at the time.
Ah, and you know, peak monitor these trends every day, and then we can have a conversation.

Steve House
Yeah.

Patrycja
I mean, clearly, if someone is an extremist and they’re sat at 65 and they’ve got frothy, you know, they’re coughing up sort of frothy sputum, you know, that’s life-threatening.
But I think that and a number on a to its it tells us very little.

Steve House
You’ve worked with elite climbers, but you’re also frequently working with patients, as you said, in various states of hypoxia. Are there things from your clinical practice that you have learned that apply well to the high altitude medicine practice?

Patrycja
I think so. So for me, I think it all boils down to expenditure or energy management. Okay, so it’s like, how much is your body paying to get to where you want to be? Okay, so…
Is the effort and the sort of O2 energetic cost of you going higher, such that it is actually making you unwell?
And that’s the very fine balance where you work with people who are critically unwell or who have severe heart disease and need operations, you become, I think, with time…
You know, it’s sort of pattern recognition. You become it you become very sensitive to picking up the little clues when people are, you know, sort of almost going over the edge because ah it’s, um how can I explain it? So, so let’s just, let’s just take the work of breathing, okay? So when I’m sitting… here now talking to you, I am a little bit stressed, but essentially I’m at rest. Okay. So my work of breathing right now is less than 5% of my total auto consumption, or what my body is using. But if I am in a hypoxic environment, exercising or trying to ascend, or if I’m critically unwell, the work of breathing itself can be more than 30% of all of your O2 consumption. You know, that pretty much means that even the effort of respiration can take you over the edge and make you sort of fall off the cliff, right?
If you’re operating within very small margins.
And it’s all about explaining to people that you work with or at work treating the people, you know, treating the patients to sort of pull them back to a slightly more comfortable position.
And I think that’s key. And the elite athletes that I work with, their skill is, I think, intuitive sort of energy expenditure management where, you know, if you think about Andre climbing start, you know, he was above 8,000 meters for 16 hours.
You know, he is right on the edge of what is humanely achievable if you look at physiology, but he, he can manage his own sort of exercise expenditure

Steve House
budget

Patrycja
like minimum, budget well enough to be able to sort of continue with what he’s trying to achieve. And that is a very difficult thing to do because once you sort of cross over, it spirals out of control very, very quickly. And I think that’s maybe the crossover for what I do in my daily work and, and working with, with clients at altitude is like how, how to keep someone in that comfort zone, which is,
You know that’s a very limited space, but it is there, and you can find it, know him yeah, okay

Steve House
Very interesting. So let’s wrap this up with kind of a lightning round of a couple of questions that I want to ask to sort of summarize some of the key things that you communicated today.
um First off, give me a good summary of the oxygen cascade concept.

Patrycja
Okay, so the oxygen cascade concept essentially is the flow of partial pressure of oxygen from atmospheric to the mitochondria.
Okay, so we take a breath, we expose our lungs to atmospheric pressure of oxygen, starting with 21 kilopascals, because that’s 21% of 100 kilopascals at sea level.
The air gets warmed up, so water vapor squeezes in, CO2 squeezes in. By the time we’re at the alveoli membrane, partial pressure of oxygen is about 13. So, you know, we have a full of a third by the time we get to the alveoli.
That determines how much binds to hemoglobin. That travels to the peripheral tissues and then by the time hemoglobin offloads in the tissues and it gets to the capillaries and then to the mitochondria, which is where it has to get you, get to to keep you alive, it’s about three kilopascals.
So, you know, I will often ask people, well, would you buy a car that essentially has seven fold? You wouldn’t. It’s not a very efficient engine, isn’t it? If you’re starting with 21 kilopascals and then you’re down to three, and the three kilopascals are what keep you alive.
You probably wouldn’t.
So it’s a very fine balance. And that’s why our adaptation to the conditions on Earth is so important.

Steve House
Give me a summary of acclimatization and the process of acclimatization, and what that means to you.

Patrycja
So acclimatization is essentially a physiological, so a normal natural process in which your body will, if given time, slowly adapt to hypoxic environment, to not having enough oxygen.
And it will happen at so many levels. It’s of which most of them we don’t even understand. But the primary thing will be hyperventilation, so getting rid of CO2 so you have more space for oxygen in your alveoli.
You will then increase your oxygen-carrying capacity in many ways. That has mostly to do with red blood cells and hemoglobin.
You will increase capillary density, so your peripheral resistance will decrease.
There’ll be more capillaries closer to the mitochondria, so there’s less road to travel to get there for oxygen. And through the hips, your mitochondria will cleverly your reset to function at a lower partial pressures of oxygen. And a lot of it is genetically predetermined in how you’re going to adapt. But there is there are big areas where that’s modifiable. And the more time you give your body to achieve that, the better it will be. So it’s the acute hypoxia that’s a problem. You know, that’s a critical illness or climbing Everest without acclimatization with six liters of oxygen, suddenly you lose your bottle or your apparatus freezes. You know, you’re in the worst-case scenario where you’re essentially not pre-acclimatized in a hypoxic environment.

Steve House
Great. Summarize for me so the individual factors in acclimatization and what some of them, what some of the big variations are between individuals and how that changes over time.

Patrycja
So, the individual factors, I think this is what we know today, and I’m sure there will be much more, and hopefully we’ll be able to do genetic testing for this one day. It would be very exciting. It’s so-called hypoxic ventilatory response.
That is essentially how much your minute ventilation increases when you’re exposed to hypoxic environment, that predetermines how you will adapt or whether you’ll be able to to adapt to altitude. Other individual factors, obviously, if you have certain diseases like pulmonary hypertension, it’s a no-go, you can’t go.
A lot of the genetic adaptation again that is something that’s predetermined we can’t do much about it but um I’ve taken many people with very severe diseases to altitude people with bone marrow transplants and I think if you go slowly and carefully you can actually achieve the objectives if if you do it sensibly so a lot of it is about monitoring the response,
What I call, you know, altitude adaptation syndrome, essentially, response and and slowing things that things down if you need to. um I don’t know, does that answer the question?

Steve House
Yeah, yeah, no, that’s great.
And I think the last question I have is the role that self-awareness plays in going to altitude.

Patrycja
So this is… I think this is probably the imperceptible, you know, sort of non-technical skill, you know, the human factor, which is key.
It’s, and that’s why how you cope mentally with that exposure is so important in your drive.
And the ability to keep your body quiet, not sort of sympathetically overstimulated to keep your respiratory rate down, you know, despite the fact that your brain is screaming, please hyperventilate and trying to keep your, you know, your heart rate down so the cells have load longer time to load and in in the lungs, right? If you’re able to do that, you actually can master that ah environment. And, you know, the interesting thing is like the the way we control ventilation, part of it is sort of conscious. A lot of it is automatic, again, at central level, chemo, baroreceptors, receptors in the lung and so on. But emotional state also has huge impact. So, for example, you know, fear will make you hyperventilate, very difficult to control. And we talked about it already that actually increasing your respiratory rate is not the most efficient way of doing it. So, you know, if you’re able to contain your fear and slow the rate down by make the tidal volumes bigger, that’s actually way more efficient. So it’s the fine ingredient of being able to manage an environment where you are not in a happy place, right? Because you’re short of breath, but you’re able to stay calm and and continue and be reassured that sort of you can do it is, I think, probably key. And that’s why, you know, Messner could do it.
Messner was not an elite athlete. There was a brilliant paper comparing his VO2 maxes to, you know, other people. He’s not superhuman. He just has that incredible ingredient where he can work with his body, his own body and recognize where he is and sustain that challenge.

Steve House
Yeah. And dial it, like if the maximum is 10, he can set it at 9.9 and stay there all day, right?
Like, and knows where that is, like what you were saying with Andre.

Patrycja
But also the consistency, I think the consistency of that, you know what I mean?
To be able to maintain it for prolonged periods of time. And this is where I think training comes in, and you know, using heart rate variability, using heart rate zones as a guide to, okay, how stimulated am I? Can I bring, turn this down a bit and actually, you know, go calmer, but more efficiently?

Steve House
Very cool. Yeah. How can we put in the show notes some links to some of the places where you’re showing up online, and you do a mountain high altitude medicine course that you offer.
You work with the altitude center in London, which whom we also have us a partnership with.

Steve House
And you are also at altidoc.org where you’re consultations for people going to high altitudes or treks or expeditions, expedition medical services and i think that that’s you know for for a lot of people that’s ah a really great service for them to be able to connect with you for that individualized support because a lot of times what I tell people with regards to training is there’s easily 50% of the people that want to train just need a training plan and they can follow the training plan and they kind of do it themselves.
And then, but as you like, get into that other 50%, there’s more people who have, you know, I don’t know whether it’s ah um a medical issue or a historical, you know, experience with high altitude illness or any kind of variety of things, you may need some more individualized support and they can, they can find you for that. So I think that’s great.
Thank you for bringing your expertise today and all your decades of knowledge.

Patrycja
Thank you.

Steve House
And it’s been, and I’m sure we’re going to chat again. Thank you so much.

Patrycja
Thank you so much, Steve. Thank you.

Steve House
Thank you for listening to the Uphill Athlete Podcast. We’re not just one, but a community. Thanks for listening.

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