Anaesthetics and ICM - Fluid balance-The consequences of getting it wrong
Summary
In this on-demand teaching session, Dr. John Vogel will discuss the consequences of mismanaging fluid balance in medical situations. He covers the three key factors of oxygen delivery, their sub-factors, how incorrect fluid balance can lead to death, exemplified by a true patient case, as well as an illustration of the normal and abnormal capillary networks in a cardiogenic shock situation. As doctors, it's important to gain a deeper understanding of the principles behind fluid balance in order to ensure proper medical care and avoid fatal consequences.
Learning objectives
Learning Objectives
- Identify the three main factors for optimizing oxygen delivery and their sub factors
- Describe the different stages of the Starling Curve and their relevant cardiac output levels
- Recognize the consequences of incorrect fluid balance in cardiogenic shock
- Interpret the anatomy of normal circulation versus one in cardiogenc shock
- Demonstrate the clinical decision-making process for assessing the risk/benefit of administering fluids in a critical care situation.
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The following transcript was generated automatically from the content and has not been checked or corrected manually.
Okay, so then that will stop when um comes in. Are you happy to me to start admitting people in and we can make it go away? But the first couple of slides there kind of sets. The pace is there's a dramatic story that so I'm I'm not. There's no problem at all for me to wait. If it's if it's okay with you, I'd rather you know, wait five minutes and get everybody in. No, that's completely fine. Want is I just introduced you. I'm usually I think we've got a lot of regular people on a cycle. See, in the in. The waiting rooms are just not admitting everyone. And then I'll just go over. Housekeeping was a swell just to give a couple minutes for people to start joining. Got some draining my eyes. Can you hear me? Yes, began. Well, welcome back to the last door for today by Dr John Vogel. My name's many showing moderating the chart today on Dad's always just going to quickly go over some housekeeping rules, So please leave your mic for meat muted unless you're answering question on. But some people have already started doing it, but yet had your name, medical school year group in the chapter. Sooner just join on. If you have any questions, you can either put it in the chart or at the end, you know, we can do an indirect recession. Were right. Uh, when you meet yourselves, I'll just keep an eye on the child in cases. Any questions? Um, I think so. So let me Just introduced are showing vagal. So today's talks on fluid balance on the consequences of getting it wrong on Doctor John Vogel. He's an I t u an anesthetic consultant. Also an avid volunteer, as you mentioned earlier on. And, yeah. So he's giving us a talk today. I'm on the anesthetics. Mighty side of things in terms of pilloried balance. Hope it and miss anything else. Did I? No, no, no. Um, yeah. So I think we're just gonna give it a couple minutes, because, uh, doctor was saying, uh, the start of the presentation is a bit of a story, so he'd like everyone to. I'm kind of join him on that. So it's gonna have a few minutes just with people start to come in on, then start in about 22 minutes. Is that fine with, you know, a bagel? Yeah, I can I can give a bit of an introduction. Yeah, good friend was anything. So the last talk I gave of those who were over attack attended was on the paradigm of oxygen delivery is the kind of, ah, simplest way of looking at a chaotic situation with the patient. You don't know what you know what to do, how to start with the stations of simplify ox and delivery. And of the three factors we talked about, um, we said cardiac output was there all important, but cardiocap it's the most important factor compared to hemoglobin oxygen saturation. Because hemoglobin, because cardiac output is rapid. Unlike, say, improving your hemoglobin if you go to altitude because you heard I was a climber and saturation is is plateaus. Because the oxygen association curve, where is cardiac output in the clinical does not. You can go 5 to 7 to eight times, uh, increasing cardiac output and of the sub factors that determine cardiac. Help it and you'll see this in a second. Um, the one that you probably will be dealing with the most often is is preloaded the words filling of the ventricle. And so the next three talks are gonna be about that. Fluids. And the reason I emphasize this so so heavily is because in my 41 years of experience, so many people basically just take a guess, and they don't really know what they're doing. And so too dot tonight's talk that will be followed by two other talks. Tonight's talking is going to try and convince you that if you do get and you get it wrong, and many times you do, um, there are serious consequence. Try and explain what they are and why they are. We even give you a bit of history of the end. Girlfriend quit Interesting. Yeah, So you let me know when it can start. Um, I think it's been almost five minutes since I started keeping. It actually could just start now. I think so. Let's start. This is just, um let's see. The consequences may surprise you. So this is just a recap of what I just said to you based on the previous talk. And I like to repeat this because it kind of fits these lectures into a kind of general scheme. Extensive kind of logical. So those are the three factors that you have to optimize to get someone's cardio oxygen delivery in the optimal state. That's well you can really do for somebody. So if you have somebody who's really traumatized, you're very ill with sepsis, those three factors, okay, you're okay. And those three factors could be broken down into their sub factors. This is all rehashing what I said last time, so I won't go through all the detail. But you can see that those sub factors could be broken into their sub sub factors. And the reason I Sure this is because if you're ever enough chaotic situation that you're not sure where to start, there's a lot of detail and people are screaming for tubes and blood and and drains Just step back. But you're thinking cap on and simplify. Go to the top of that pyramid if you like. Just remember the three factors, all the rest or details you work out later, but today we're gonna talk about probably the commonest sub factor that deals with the Communist most probably the most important factor. And that is preload so feeling of the heart and something you do all the time. So here's ah true story and it illustrates the civil Straight it to me, Uh, how important it is to get this right. And this is one case that I will never forget. And this was a 59 year old male. It was previously healthy. He was a builder. He was having routine surgery. In fact, was hemorrhoids of the whole thing. During the procedure, he had a sudden marry cardio infarction. Very likely secondary to an an inflect allergic reaction. So this man has had this massive myocardial infarction and he's taken to the i t. Where I was the consultant and he's in what we call cardio cardiogenic shock. In other words, his heart is so infarcted that his muscles aren't pumping anymore. His heart muscle is not pumping. And we know that for the last 30 40 years, the mortality if you have cardiogenic shock is at least 50% and it really hasn't changed a lot. The thing is that there's a reversible component, you may have a chance of seeing the person and the one reversible component in this case, we thought, was what he has included. Coronary artery So this man is taken to the intensive care unit. He has a very low BP. We had a cardiac output monitor into, and that was very, very low. His skin was modeled and blue, like rock four trees. And that's the terrible signs is what was interesting was his oxygen. Saturations were very, very low, and he had. He was intubated. His pulmonary demon was pouring out of his tubes so his lungs were destructed. Water and in the demon fluid, very low cardiac output model skin. So it's been a terrible perfusion, very low saturation and pulmonary edema, fluid pouring out of his tubes. So if you go back to the auction delivery paradigm, he's really, really in bad, bad trouble. He's on maximum doses of every heart stimulant every in a truck, which means that there's nothing else we can think of giving this man. No, if you're going to theorize it, theorize as to what he's like and whether fluid might be a noxious or not. This is a normal starling hurt on the X axis. You have the feeling of the ventricle, and you can either if you could measure the volume. But most often we measure the pressure. That's a CBP or the Rachel pressure on the, uh X on the y axis. You have the cardiac output, and normally and this is, I presume, the Cardec the starling curve of you and myself because we're healthy. We don't need more cardiac output. But if we did, because we're on the steep slope of this curve, if I were to give you fluid, you ought to increase your cardiac output with a relatively small increase in filling pressure. Well, what we expected with someone cardiogenic truck was they had a very low and flat curved to the right. So that's where they be situated on the very flat part. And you can see the cardiac output extremely low compared to the normal. And if you fill them because there's on the flat part of this very, very small flat curve 50th, the right, If you fill them, you're gonna get minimum with any increasing cardiac output. But you're going to get a meter increasing. Fill it. So what? That mean I'm feeling pressure. Sorry. What that means is you're gonna create more pulmonary edema. Now if you have this person who's got such severe come a Dema and they're really on a knife It if you give them. If you increase their pulmonary edema, you may well kill. So you can see this is weird. A really, really tough spot if you want to see what if you had what they called sidestream dark field spectroscopy. Don't worry about the term. It's just that if you had a window into the capillary network, this is what a normal capillary network looks like. Okay, you can see the nice rolling cells, big boulevards with small side streets that aren't too far apart. So oxygen and waste products convict use I/O to the cells. That's a normal circulated reflow. And this is what cardiogenic shock looks like. And when you saw this man's blue modeled legs, um, you can well imagine that's what it would probably look like. Okay, so here is the dilemma. And this was a really dramatic dilemma. This man was on maximal support. Everything we could think of his cardiac output was very, very low. He would not survive with that out Onley cats. And it's a small kits, but it's only cancer is that if we could transfer him to a church. Recenter. We has a coronary Catholic Catholic laboratory. We have one, but it was closed for repairs. So we had to get to another hospital where he might just might have a small, small chance of being able to open up his coronary artery. If that was the problem, we assumed it was. But the problem was this. The ambulance was not going to take him. He was too sick to transfer. They said if he is the way he is, you will die in the ambulance will not take. So we've got to get in just well enough to be able to get him to the ambulance to, given that minuscule counts off opening up a coronary artery. If we can't improve his cardiac output, he's going to die for sure in argued it. So how about fluids? Would you give this man fluids? Anybody very in mind that if we gave him fluid, we were expecting, given the Starling curb the very flat starting curve you saw we would increase his pulmonary edema. We reduce the saturation even further. We'd reduce his oxygen delivery even further and we probably kill them at the end of the infusion. So what would you do? Anybody? Can you give medication? If you can think of something else to give him? We had him on everything we could think of. Believe he was 60 diabetics too. Well, so the question is diarrhetics That might help is permanent demon, but it might also decreases. Palmer is a cardiac output, so we give him a blood transfusion. Well, it's fluids, if you like. Okay, First you got to get blood work done up time, but let's say you had blood handy. You're giving him fluid. And as I just said, that fluid may increase his pulmonary edema. So we're basically on a knife. It So what we did. What did we do? So question was fluid, you know, What do we do? Is there a way of giving him fluids safe without actually risking his life? Like seeing, you know, we had expected him to die from pulmonary edema. What we did was we raised his legs. We did with the Copaxone leg raise. We'll hear about that in the next lecture or 2nd, 2nd or third lecture. But that was a way of giving fluid without actually giving him fluids. So if he doesn't respond, we could lower his legs. And we did that. And to my other amazement, I really didn't expect this. His cardiac output massively increased. Um, and then we gave him fluid. He, um he did well enough to get transferred to a cath lab, and they found that his left main stem was blocked and they had the manic unblock it, so that saved him. So that was a dramatic example of where trying to guess how someone's gonna respond to fluid and what could happen if you guess if you get wrong if it's either too little or too much. So I was just to sort of, you know what your appetite. So we're gonna talk about what happens. You get too much fluid or you don't give enough fluid. So let's start with someone getting too much fluid. So this was a study that really surprised a lot of people. Now the circumstances are particular, but it's just that was very call into question. A lot of we thought we knew, and this was a study that was done in sick Children in Africa who had sepsis, often malaria, but not just pneumonia, diarrhea and vomiting. Gastroenteritis but sick killed it. Now, normally, what we do with someone is very sick. We give them some fluid to start with. And in this study they did. But they also gave nothing and looked at the difference in mortality. 48 hours. This is called the feast study. So there's they gave different fluids, albumin or stay in line. And as you can see, there was no difference in mortality it 48 hours and then they gave one of the groups nothing, and they had a much lower risk of dying. Know that again? The circumstances are very unusual. You know, most people are not in Africa with six Children with malaria, but it just called into question the idea that maybe just giving fluids or isn't automatically a good thing. So it just made you question that sort of dogma. And this is one study of many many studies, also the same thing that if you look at patients who are very sick and critically only with critical illness, and you look at their cumulative fluid balance over days and we do this quite frequently united you, we look at the accumulation of fluids. The more fluids less fluid you accumulate, the less cancer you have of dying. So the lower your fluid balance, more cancer surviving. Now you gotta be careful here. This is an observation study, as they all are and and fluid balance studies, and the reason that that's important is that it could be causing effect. So maybe you're getting fluid may cause harm, but it could be association. The sicker you are, the more fluids you need. So it's very difficult to parse apart the two. But there's a lot of biological plausibility as to why too much fluid need bad for Well, come on to that. So one of things we know is that too much fluid and dangerous your glyco. Okay, Alex, you're probably saying to yourself, Look like a what? So this is gonna be something that I hope it's going to open your eyes because I find that's probably the most exciting new organ we've discovered in the last 20 years. And a lot of people don't even know about this. We could really amazes me. So we all have learned about Ernest Starlings, vascular barrier, single vascular barrier, but hypothesis. And it's a hypothesis. So what did he say? And you probably won't remember memorizing this stuff when I was in medical school. You have? You're in red, the intervascular space. You haven't greatly interstitial space. So that's outside the vessel and green. You have the endothelium, and we all used to make my stomach hurt. How much pressure was forcing fluids out of the intervascular space? So that was causing transit eight. And we had, um, collide. Osmotic pressure. COPD, which was 80% was albumin, which is sucking fluid back into your getting to serve continuous circulation. And there was a little bit more transit date going out, then fluid going back in so that excess food would go down the lymphatics. And that was what Starling was was taught. We all learned that medical school, but there's interesting. There have been several aspects of this that I have called into question. So one of the aspects that scene in experiments is that if you make the charismatic pressure inside and outside the vessel the same, theoretically to treat nothing sucking fluid back in. But it's still it's still sucks it it. So there's something going on here, so the model isn't right. And here's the new model. It was proposed. So there's your intervascular space and I've Drawn album, which is the main card asthmatic molecule that sucks fluid back in, and I've drawn that density. We'll just represent the number of albumin molecules. There's your endothelial. Still, there's your interstitial space, and I drove on the molecules to be the equal equal density on both sides of the endothelial barrier. But there's one aspect that was missing with, um, with, um, start her and that is this. There's something called the glyco Kill X, and you can see it's, uh, it's kind of ah, trap for lots of albumin. And what is it? It's It's a mess. It's filaments of glycoprotein and proteoglycan Z, and they do a lot, a lot, and they're throughout the entire vascular system. So let's have a look at this in detail. So what's what's saying? Basically, is that because you have yes, you have equal amounts of albumin on both sides of the endothelial barrier, but because you have such a density in the glands. Okay, Alex, it sucks it in, irrespective of what the quantity of albumin is in the intervascular or space. So the density of albumin where it really counts is the glyco kicks. And as long as the glyco okay looks intact, you should still not leak fluid out. So that's going to question something that we've been talking for over a century. Does this glider kill it exist? Well, yeah, Let's look at it. So this is a electromyographs scope of the glyco. Okay, Looks of a blood vessel. And if you look closely, you can see these kind of filaments and they're a said. They're kind of a measure and they created drill. And there's your electrical. It's it's about 0.2 micro. So the's filaments have got various family members to them and the ones I've chosen and read by the most representative. You have Cindy camp, you have high or your rent and and you have heparin sulfate. Now Heparin sulfate sounds to me a little bit like heparin, doesn't it? And that's exactly what it does It Basically, you're steer, and the theory is Teflon, and as long as it's attack, it stops red cells or white cells and platelets from sticking. But if it's dislodged because it's safer, Glycolax is destroyed and the hep A and stuff. It floats down stream. You get something called auto heparinization, and that's quite serious. So time a little kids. Who What is that is our cartoons of the Glyco killer? So what's really amazing that this click of calluses it does so much. So let's go to the bottom left. It's it creates nitric oxide sentence. Now. What's really amazing is that those filaments are like small sapling trees, young trees blowing in the wind, and they have mechanics receptors at the base. So with the strength of flow, you're getting more of a bend in the like, the trees bending in the wind and that that's attached to a mechanic receptor. And those may be kind of receptors. Release nitric oxide, which controls the diameter of your vessels. You have one willebrand's factor in antithrombin, which also control the adherence of platelets and white cells. You have plasma proteins that are embedded in the blood circulates as you saw earlier, creating color as monitor pressure. Some flu doesn't leak out, so you can see they're multiple effects of this glyco. Okay, Alex, What's interesting about nitric oxide sentence, by the way, is one of the hallmarks of someone who's got septic shock when the first things you see is they're very dilated. And the reason is is because the septic shock damages the electrical it so they don't control the size of their blood vessels. And that's that's the whole market, someone who's very septic. So what happens if you destroy your glyco? Okay, looks well. You get some of the filaments. These proteoglycan Zwerg lack of proteins is a sugar proteins. Your protein trip. It's going to be simple. Float downstream in a closed damage downstream. You lose your nitric oxide sentence, and so you lose the control your blood vessels, your massively dilated, which is classic with someone who's accepting truck. You have inflammatory cells, which normally don't stick. Now there's nothing. There's no Teflon to a predictor prevent um, sticking. So you're going to get inflammation and you're going to get platelets. It hearings, you get thrombosis and you're gonna get because that you're losing that. That college asthmatic pressure, which is inherent to the glad for Calix you're gonna get leaking protein nations fluids you're gonna get exudates. That's all that's classic with someone who's in sepsis. So what are the causes of things that will damage your glyco Calix. Well, tumor necrosis factor. That's a cytokine. And the toxin that you get with grand negative veterans leukocytes ir That's a systemic reperfusion injury. You make something a scheming and you re perfused it. You get a release of oxidated oxidative molecules and a n p atrial natural like peptide. That's a peptides to create when your heart is over distended when your atrial over distended that will damage Requip Gilkes and you were to get a PSA said capillary leak. So does this actually correlate to anything? Okay, so in this study, they looked at one of the, um, one of the components the glyco kill. It's just a a zar a measurement, and they looked at high or your rent, and it could have used in the counter any of the other, Uh uh, parts of the blood circulates. They chose high all urine. And this is someone who's healthy. So there's a little bit nicked off and floating down street. If you're septic is more if you're severely septic even more, and if you accepted shock, it's off the scale. So what says is this is that it's It's not only part of the mechanism, but it's also a prognostic factor. The more you have your headed glyco okay, looks the less likely you are to survive. Now I'm gonna take it on a story because this this talks about fluids. And, um, I've been working for 41 years and I've worked on both sides of the Atlantic. One of the most boring debates I've heard over for decades and decades and depends on whether you're in the United States or they're in Europe is what is better to resuscitate somebody with crystalloids or colitis. So for decades, the Europeans let not exclusively but mainly by the British. Were coloreds our best. Because if you're someone interest us taken in theory, if you give a leader off the perfect Colyte of leader stays in the circulation. The Americans said, Well, that's true. Maybe, but there are disadvantages to that and less expensive to use Crystalloid. So what are we talking about here? So let's go through some very basic physiology. So if someone is about 70 kg, this is just just rough. Rough figures about 60% of your water, so your total body water is about 45 liters. Again, there's a rough figures. If you look at the interest, sell your volume of fluid of water, the interest. A lower spaces, about 30 leaders. So of the 45 m 30 leaders is the interest a lawyer space, which is by far the largest component. If you were to look at the extra cellular space, about half of the intracellular space, or 15 liters of the 45 is extra cellular. An extra cellular is comprised of two components. There's the intravascular states That's about three leaders. Don't forget. You have about a five leader volume of blood in your intravascular space. But much of that is within the cells of your red cells. Your white cells, your platelets. So we're talking about the fluid that's outside those cells, and that's in the intravascular space. We're talking about three liters and, um, and the extra and interstitial space sorry is is about 12 years, so that's 15 m minus three years. That's what's outside the vessels outside the cells. That's the extras extra vascular extra cell your space. So if I give you dextrous and there's nothing stopping dextrose free water to go right across all the compartments. It'll go away across all those faces if I give you Ah, electrolyte crystalloid something that has electrolytes in it. Those electrodes stop the fluid going across the interest cellular membrane. So it goes into the intervascular space and it goes right out and it fills up the extra cell your space. And if they give you the perfect Colyte, it will only stay in the intravascular space. Now, this is theoretical. This is what was the debate was. Why would you give, say, heartburn solution whereby you lose three quarters of it into the extra vascular extra cell your space and only a quarter of it stays intravascular when you can use colon when all of it stays in so you get more bang for your buck. And for years the Americans said no, no, no. Hartmann's is fine. You have to get four times more, Yes, but it still fills up the interesting space, and the European said no, no colitis better. And then around 2000, so everybody swapped sides and the American suddenly said no. I think you're right, College of Better and the European said, you know, colitis don't really do it. We thought they did. They don't stay in the past, your space And there are lots of reasons for this. Some of it had to do with the wars in Iraq and Afghanistan, where the soldiers and the leaders and leaders of fluid with them. And they thought, Why not carry less fluid? You know, to recess They are, or soldiers because it's very, very hot in those countries, as you know. So there was a squatting the side, so it's a bit of a mixture where the European simply say colds don't work. So let's look at this again. So if I have a liter of fluid that someone's needing resuscitation and I give him a liter of fluid. In theory, if I give you dextrose, one leader of dextrose only 70 mL stays intravascularly. The rest of it goes outside the vast vessels to the interest cellular into the extra cellular space, give you crystal light apartments again about a quarter of a theoretical state intravascular three quarters, or leave the vessel and stay extracellular. But it will be outside the vessel, so one quarter in the vessel and three quarters outside of this. If I give you the perfect Colyte. Theoretically, it all stays in. Now the question is this. Why did these two side swap? Most importantly, why is that? The European suddenly said, you know, colors don't work. Well, this could be one explanation. Okay, So this was a study where they looked at going tears, who transfuse with these these fluids, either Colace or Crystalloid, and they want to see how much would state in the circulation. But what they did was wondering of volunteers. They gave fluid without extracting food without extracting blood beforehand. So these people were made hyperbole. Me and the other group. Sorry. I got it back to front here. And the other group, we had extracted blood and they filled them with, um, with these tested fluids, whether it's albumin or head start, which are both coloreds. So they're they're normally, so they've taken blood out, and they've given food back. So the volume is normal. And if he modality because the cells that were left are being diluted with the clear a cellular fluids they're given. So they found that albumin about 85 86% stated head of starch, which is a Colyte 90% stadium. So that's more or less what everybody said for decades. That's, you know, that was acceptable. And I don't know where they got this idea that colitis don't stay in the circulation. What about ringers? Well, they found in this study was about about 20%. So about instead of quarter 25% is not 20%. So ringers did exactly what everybody expected. So most of it wreaked out of the intravascular space. Wouldn't about someone who gets fluid has not had food removed from them to their hyperbole? So they're got more fluid than when they started. Where do they find their? In that case, the coloreds were much less effective. Then people were predicted. Why? Well, because if you give somebody volume and they overload themselves, they secrete something called naturally peptides. In this case, a m p. Atrial, not your attic peptide. So could that be the reason that they're sick? A difference cause atrial? It's very picked up like brain metric BMP and A M p R. Hormones that's secreted by the heart and the response to acute volume loads. And so this just security Listen in the suddenness case, Siris of operations with a They get more or less volume to patients, and they measured and pee with low volume. You had low MP with higher volume. You had high empty, so it does what you expect it. It increases your ent if you give more fluid. So what is the NP do? The glycol kicks when we said these are the things that damage. We've got your kid extent all important. Glad you're Calix. What is an PDO? Well, here's a controlled model. This is an animal looking at the glyco kicks in black around this vessel, and now they're going to infuse recombinant and pee. Look what it does to the glyco kicks it strips at all. So if you're stripping off your bladder can, it's It's not surprising that the colon you're infusing, which is overloading you if you don't remove fluid. First, um, you're gonna get leaking fluids. It's going to leak out because they're glad you're kidding. That's what keeps your fluid in your vessels. Okay, and is it important? Yeah, it's really important. That's why I'm so I'm so excited off the subject. It's a vascular barrier, so it keeps your fluid in your vessels instead of leaking out, causing people to get massively a Demetrius. It's your body's test flown, so it stops thrombocytes of platelets and white cells that he's sticking to the sides of the vessels it controls. Inflammation cause. Don't forget, your monocytes will leak out through there and cause inflammation. It controls your vessel diameters we saw earlier with the metric oxide. And if you think this is not a hot topic, think again. So these are just some of the articles I found on various subjects. So whether it's preeclampsia, d I C renal injury, sepsis and magic truck, Alzheimer's disease, micro circulated problems, Crone's disease, coronary syndrome, trauma to lung injury, dengue fever, all these disparity medical subjects. If you look at the literature, they're all talking about the glucose, too. So it's important that, you know, that's I'm just to illustrate this. You heard of disseminated intravascular coagulation. Some people call D I C, and some people call it Death is coming because it's got a very, very poor prognosis. This is what it looks like. If you look back of those videos that sugar really look at that, it's absolutely terrible. So you got those black areas those air from boast vest microvessels. So you're getting get thrombosis and you're going to get bleeding because your damage or black or kill X number I told about the heparin. Is that started? Heparin is destroys the heparin sulfate to it's gonna anticoagulant you displace, you bleed and you're going to get you lost your Teflon, you're gonna thrombose You believe in your clot? D I sit? The other problem with overfilling Somebody were talking about the consequences. It was getting too much fluid at the moment is you get back pressure, you get like a dam damage back. Um, fluid. The damn we're talking about is the heart. So there's something called the Cardiorenal syndrome. And when I was in I t u and we'd get the cardiologists sending us patrons whose kidneys were no longer functioning because they were in ST heart failure. And they say we want you to dialyze them and we say, Well, the problem is that their kidneys, the problem is their heart. And we can't give you a new heart getting a transplant if you can. But we didn't do that. So they say, Yeah, yeah. The problem is, we always go back and forth. And so what is the cause of the Cardiorenal syndrome? The Cardiorenal syndrome? They're different types, but the commonest type type one is whereby you you're failing heart. Is it Zocor? Minal? It's end stage, heart failure and one of the last organs to be impacted by your feeling. Heart is your kidneys. Now we just to think for years. That's because your heart's not pumping enough blood to the kidneys. So your kidneys were starved. Blood? Well, it's not quite true. So here's the next years of study up. This has been through several times, Square into this. There's on the Y axis, the grill, your filtration rate. So how much filtrate You're producing your kidneys and on the X axis, we're gonna look at somebody who has a high cardiac output and a low central venous pressure. The CCP is the pressure in the right heart, so that's your damning back pressure if you like. The next patient's got a low cardiac output, but a low CBP. So those are two groups of patients. High cardiac output, low cardiac output, low cdp, look low, CDP. Then we have a group high cardio, but at a high CDP and a little card a cup it in a high CCP. And what is the common factor that explains all this? It's the high CDP, so the problem wasn't due to the heart, not pumping enough blood to the kidneys. It's the heart. Can't get blood out of the kidneys because there's a damming back of blood from the failing right heart that the kidneys can't get the blood out because the kidneys are in a capsule that's not distended ble. Um, it can't. It just gets the pressure inside, gets higher and higher, and so it can't get rid of the blood. If you like, can't create. Remember your filtrate can't you can't go. That's the cause of So it's venous Congestion is the cause of your worsening renal function when you have advanced heart better the cardio renal syndrome. So unless you get someone's heart republic again, um, your kidneys aren't the problem. It's your heart. There's also a backpressure on another word, and that's the liver. There's something called cardiac liver, cardiac cirrhosis, we call it some people call it much make liver because it autopsy. It looks like nutmeg, and again you get cirrhosis and liver not from alcohol or not from the metabolic syndrome, but from heart failure because there's so much back pressure on the liver and you get hemosiderosis of the red cells breakdown and the iron destroyed. It's very damaging to the liver, but it damages your liver. It gives you cardiac cirrhosis and last of all, not last. But we're the most important ones. I think is this is if your heart is failing your right heart feeling you're gonna get a raise in right atrial pressure or CDP the same thing you get. Venous congestion of the damning back of Venus blood that's going to impact on your intestine. Now your intestine is one massive abscess. You've got some people say, Ah, 100 times more microorganisms in your intestine that you have cells in the body, some thinning of the order of magnitude. There's a lot of cells, and there's something called the microbiome, which will hear a lot of. And the reason that those those microorganisms don't cause all kinds of damage to you is because you've got a serious about five defense defensive walls around your intestines. Everything from there's patches to lympho of Lymphatics. It's serious and serious and Siris of protective of, uh, elements to stop those microorganisms from causing damage to the rest of your body and leaking out of the intestine. But if you have that high venous pressure that will cause congestion that will damage your intestine. So what do you get? You get bacterial translocation. The bacterial of the factory and their products will leak out through the intestinal wall into the lymphatics and the lymphatics. Go straight to your heart to lungs, and you get all kinds of damage and you get side kind release, which causes inflammation and anorexia and basically your bloody ill. So these right particular failure is a a serious cause of intestinal congestion, which causes translocation of bacteria. So that's a really serious problem with too much fluid. Okay, what about Not enough fluid. So we covered too much food, and we're not Not enough. So what happens if you don't have enough? And sometimes it's obvious, but sometimes it's not. This was a really fascinating studio. This was done on volunteers. These were doctors. No, that Yeah, they're young doctors in London and they quote unquote volunteered, and what they found was this they were going to bleed them in a serious of to eloquence of two two sessions, we're gonna take 600 mils of blood from from them once, and then take another 600 mils of blood from such 1.2 leaders in total, out of roughly five liters. That's a lot of blood. And what they're going to do is measure some common cardiovascular parameters. So they were going to take the 1st 600 mils, and they were gonna make your BP. They're gonna measure heart rate. They were going to make her, um, cardiac output. They were using something called a superstar. It'll Doppler. So you have a nesting cardiac output? Doesn't matter exactly how they did it, but and most importantly, they did something that I don't want to go into detail with. But they had a way of measuring the blood flow to the to the stomach. So that's your four. Good. And the way they did that was using their mental. PH is of your stomach against your stomach because it again the the techniques a little bit complicated, but it's basically telling you, Is my stomach getting enough flow when you say, stomach. You're talking about your gall bladder, your liver, earlier upper intestine, all the four guys. So what did they find? 600 mils has taken off. BP, heart rate and cardiac output. What do you think happened to them? Thank you. Sorry. You think it's raised? Know degrees? Okay, well, nothing. Now, don't forget these. A relatively healthy young volunteers. It's not an 85 year old woman. Okay, but think about this. You want the ward, and most people don't have a cardiac output monitor on them. But the nurse will say to you, Oh, his BP is okay. Is heart rates okay? And yet this person may have, you know, in this case, 600 mils that are missing and they're still fine, the gut mucosa peak. So that's a measure of the flow to the gut. That's one way of measuring it went down. So so far, you've taken 600 mils off. The only sign that something's wrong is the flow to your gut is reduced. Everybody else is fine. Now, let's take another 600 mils. That's 1.2 leaders. That's, um, that's almost 25% of your bloodline. what happens? You get a picture in heart rate. What do you think? Drop? No, Surprising. I must confess. I find that surprising in this case. Young, healthy volunteers again. Don't forget that. It's not an old person. Um, stayed the same. But again, I find that really amazing because that means that if you're going to the ward and someone said, Oh, Mr Jones is okay. He's got a normal BP and heart rate. Well, in this example, uh, yes, he does. But he's already lost 1.2 liters. That's a lot of blood, Kartik. Help it? No, it dropped. And most importantly, no, not most importantly, expectedly, I'd say it may cause a peek sort of flow to the gut plummeted. But it was really interesting in this study, by the way. And it taught me a lot was I read the study, but I also met the authors in a meeting and we went for a drink afterwards. And then they told me something that was not in the paper. And I thought that was probably the most important and interesting aspect of this whole study was they said all the volunteers had their own blood re transfuse into them. Immediately afterwards, they were back to normal. And what did they find? They all had for about 48 to 72 hours. Flu like symptom. Now we don't know for sure why, Like, curious had could imagine that they probably got translocation of bacteria because their gut with suffering don't forget the gut suffers. You have to it float flood of blood because the damning back, the high venous pressures. But if you have not enough, that also will cause translocation and they get the release of cytokine is when you have the flu. Well, it's the side of kinds of make you feel awful. So is this logical? Is is possibly true. So this is a study They looked at hyperperfusion inpatient nothing patient patients and men who are exercising maximally, we're not actually 70% of maximum. So what they did here was they measured something different. They make her something called the 02 gap Again. It's another way of measuring flow to the to the stomach, and in this case, the higher the gap, the higher those numbers that you see on the left hand side, the more you're the less flow. Your stomach's getting so it's kind of the inverse. So the higher the number, the less blood flow into your stomach. So you see in green they're cycling to 70% of their maximum work. If and you can see the flow to their stomach is is dropping. When they stop, it goes down back to normal. Well, you can imagine, as the bloods going from there intestines to their legs, cause there they're exercising. Excellent. And there's something called I Felt Intestinal fat. Fatty acid Binding protein doesn't matter, but it's kind of like your intestines proponent. It's a it's a it's a a protein that leaks out when your intestines are suffering from ischemia. And again, when they were cycling to 70% 70% of the maximum put it went up. So it shows that your intestine, this suffering and when they start up, the came back to normal yet. So, yes, you will definitely get some intestinal suffering if you want to call it that. Uh, if you don't perfused your intestine adequately and what about two minutes? So we said Okay, so that's fine. But what about translocated? And what about feeling flu like illness, and we're extrapolating here well with this. So two gap again. That's a flow to the stomach. They measured tumor necrosis factor. That's one of the side it kinds that's released if you get translocation And look at that as that gap went up. So you're getting less flow to your intestine to your stomach. In particular, you're sighted kinds go up. So that's kind of collecting the dots, Isn't it saying yes. If we don't get enough flow to this, the four gut we're going to get translocation get translated, really Get side of country least cause you're gonna, you know, trigger your inflammatory system medicine make you feel ill. So this is kind of putting everything together again so you can see people that I've got people back to that study. They've lost 1.2 leaders. The blood and everything else looked pretty normal. What you can imagine, you know, if that was a patient and they're feeling bloody ill afterwards because they have this really society kinds. That's not a good thing. So there was a correlation between CO2 gap 200 s factor. So the hope, the correlation, the whole point of this is to say you may have someone who's relatively under filled, and you may think they they're okay, because your BP and heart or you're okay? Not necessarily. And, yeah, One last thing is, when they refill these patients, their their their chemo genetics did not return to normal. Immediate. Okay, So I'm gonna take you through some a bit of history here because I find this fascinating. So years ago, it was noted by, um, by surgeons in United States. But after a non operation, patients didn't pee. They didn't urinate, not much. And the question was, why? And there was a famous professor of surgery. And it's the surgeons, the United States who tended to set the standard, if you like, for everybody else and this'll famous certain. And Francis More said, I think it's because this is before 1965. Okay, it's a long time ago. I think that it's because your body's been traumatized by surgery. Shorter is nothing more. Anything less than controlled trauma. You get hit by a car. We have surgery to pay on this. You know, they kind of severity the surgery. It's the same. You've been trauma traumatized once controlled was not. But they're trauma and your body reaction same way with something called the Evan Flow of trauma. It's a classic model of of trauma. So he's saying, I think your body secreting There's a neurohormonal response to trauma, which means that your body is going to try and save fluid. But your body's not lacking flu. It's just that the way it's it's built to say fluid if you been traumatized. So, he said, if you want to reduce complications, give a little amount of fluid. You want to give a lot of fluids and get more complications because that fluid's not needed. It's just that you're gonna overload. So fewer complications you get to keep them dry. That was Francis more, and everybody followed his way of thinking. You're thinking because he was a famous surgeon. Every said, Well, Francis More says that that must be the way to go and guess what? In 2018, there were studies that confirm this. In fact, two studies I could picked out I picked out saying all your after surgery is a non renal stimulus. It's not because you're lucky and fluid. It's because it's the trauma of surgery, and a second study in 2018 said the same thing. Not only is that part of the recovery period, it's to be anticipated and permitted, because it's not a matter of losing fluid. It's because your body's reacting to its normal, the normal traumas and neurohormonal responsive trauma. Okay, that's fine. So it's confirmed. We know about that, right? Well, maybe not. So there's a thing called the third space, which you may have heard of very simply. If I take a hammer and smashed my elbow and I break some of the bones in my elbow, you're going to see my my elbow swell. And that's swollen elbow is got fluid in it. That's not taking part in circulatory functions, not part of my body. If you like, It's sequestered in my elbow, and that's what is called the third space. And of course, the more the trauma, the greater the third space, so sequestered fluid. So it's almost like you're not blood, but you're so much like you're lost fluid. It's, um, it's, uh, you've hemorrhaged inside yourself. If you want, it's fluid. That's not taking part in the normal exchange of fluid fluid. Strange. So what happened here? This was a man named Thomas IRS who is a professor of surgery. Exactly where I worked in Seattle, and he was just after 1965 and he was very important man, he said. He challenge a more and said, No, no, no, I think it's the opposite. I think the problem is that these patients are relatively hypovolemia because yesterday have the most blood but the fluid sequestered within their traumatized tissues. So we've got to give something to compensate. So his theory was that the more fluid to give lower the complication and Tom Cars is also known for something else. He was the resident who received President Kennedy when he was shot in Dallas, and I just put that down because that's how I remember Tom Charge. So what he did was interesting. So he did a experiment on each of dogs, and he bled them until they were to shock. And the first group he gave the same blood volume that he took off of that the second group, he gave the same blood volume he took off, plus ringers lactate, and he found that in the first group. Just the blood that's that given back. 20% survived in the group that got the extra fluid in addition to the blood. 70%. So he's basically saying, When you've been traumatized, you need more of just what you draw. So if I've lost your blood, you don't need just leader of blood back. You need the leader plus ringers, lactate or some crystal light or some fluid. Now he did a major study, and this is a landmark paper. It's a long time ago. He he labeled, um, extra cellular, uh, electrolytes. So Sofie and he was able to measure the extra cellular fluid. And he found that the greater the trauma, the greater this food was sequestered and the functional extra cellular food was diminished. So, basically, as we just said, you're losing fluid into your damage to foods. But he made one big problem, and they said, That's why you have old your it because you're not. You're not. You're You're lacking fluid. It's inside you, but it's in the traumatized. So you've gotta replace that third space Now. There was a problem, and the problem was this, um, he, his study was, may have been qualitatively correct, but quantitatively, it was way off. He extrapolated this mass was way off. We don't know this now, and he basically said And again, he was a surgeon who set the pace for the United States at the time that if I lose a leader blood, I will give you a leader blood, and I'll give you seven or eight leaders of crystalloid. Now, I worked in the trauma center working the second largest trauma center in United States. I came from your well in American black team. Was training York. I couldn't believe how what fluid. They gave people there that people would just blow up like balloons after being traumatized, hit by a car, gunshot wound, stabbings. They just, you know, if you lose the leader blood to give you your blood and they gave you, like, eight leaders of crystalloid is amazing. Now, this had major consequences during the Vietnam War. So this is a normal looking woman I don't talk to. Okay. Nice. And pigs like a sponge. This is what a very a demons'll, um, looks like And so what they found was during the Vietnam War. But this also happened in civilian casualties and trauma centers in the United States, Shock Lung seemed to follow. We didn't know what chocolate was. It does that in those days, it seemed off, came out of nowhere, came out of successful resuscitation from Circulated, collapsed. And they think it was due the overzealous administration of liquids, which caused the pulmonary edema. So in some ways, what I'm saying is there the fluids were trying to solve the problem of the circulating recibe, and they probably did as they were successful in assisting a lot of the soldiers. There's something called Denying Lung is the soldiers and denying where the hospitals were located during the Vietnam War were being resistant and lots and lots of fluid, thanks to tires experiments. But they had this new disease, if you want to call it that called the 91, which is basically pulmonary edema, shocked when they call it. So you're solve one problem, but you create another by getting too much fluid. And guess what? His experimental, uh, hypothesis again in 2018 was confirmed. They said if you restrict fluid, you're gonna get a higher rate of kindred, So this is kind of, um see, you got two things going on here. So 2004 to 1965. Talk to more pressing work. He said, Keep them dry. You have fewer complications afterwards, people, um wet. Keep them dry. 1018 going back and forth, back and forth. So where is the sweet spot where we really want to be? So if you're confused, don't worry, you're not alone. But there's another approach and this was interesting. That's the thing. So they said what said was guessing how much fluid to give. What if we measure starlings curve and what if, before safe trauma before surgery we were to fill you, we'd measure cardiac output. We fill you until you make the top of your starling curve, okay. And which case you're fluid. Responsive. You're responding fluid by increasing your cardiac output, and we take you right to the top of your starting her. Okay, Means we take is that red dot until you're no longer food responses. That means if I give you more fluid, you're not gonna increase your cardiac output. So we've taken you as much as you can as high as you can go without damaging yourself. So you're not overloading. You're just giving him. You're feeling you're feeling the tank up to maximum baseball. That makes sense. That's some people were saying That's what you could do before surgery if you want to reduce complications, so it's like an intelligent way of trying to determine where you are. Well, there was a really interesting study done, and what they do is they took pigs and the measure of the cardiac output of these picks, and they gave them pancreatitis experimentally. Pancreatitis is a burn inside your retroperitoneal state space. You lose a lot of fluid. So what they did in the first group of pigs the normalized stroke volume. So, basically, you lost fluid from the pancreatitis, and they just gave you enough fluid to get you back to your starting point. Okay, In the second group of pigs, they've lost a lot of fluid from the pancreatitis. And then they gave enough fluid to get them to the top of their starling hurt. So they maximized. Stroke. Strovite is cardiac output times as per beat. Okay. And where did they find? Remember our old friend heparin sulfate? One of the elements that constitute the glyco. Okay, Alex will in a normal stroke volume. That's what they found. Maximize stroke volume. And don't forget these are both inflamed pancreas. So there is not the pancreas per se that's causing the release of heparin Celtic. To some degree, it would be. But the only thing of distinguish between those two groups of inflamed pancreas one was taken to the top of their starting career on the other. One was just taking back to normal where you and I would be today right now. And what about I'll six, which is one of the site of kinds again? Yes, they're cytokine release because they're inflamed pancreas. You have a massive inflammation, so that's high in a normal stroke. Fine. But look at that. The maximum stroke prime. So the fact that you're maximizing the stroke Ryan, you're increasing to the top of the starting. Her has an effect on your glyco can. It's and on your inflammatory side car and interesting. When they looked at the pancreas pancreas under microscopy, they found there was much more a demon inflammatory Dema in those pigs that were normalized to the top of their starting. So to recap Elice, if you under assess state or over assessed eight. You're probably gonna run into trouble. And so if you under assess state, you're going to get the organ is skinny. We saw on the translocation we saw earlier. If you're over assessed eight. You got the two problems of damning back blood. Remember? We told it, Denny, back into your kidneys and to your liver, a cardiac cirrhosis, cardiorenal syndrome and translocation of bacteria from your intestines because they're congested. And if you overload, you're going to damage your glad your kid because of the atrial metric peptide, which again will cause all kinds of damage. So you probably want to be somewhere in the middle. Know where that is When you find out. Please tell me. Okay. And don't forget, as usual, if you're not sure if you have two opposing views which we seem to have here, the more likely answer is somewhere in the middle. And as of today, I just say be reasonable, but least you know where we are. Okay, That's all I have to say about that topic. If there any questions, I'll be happy to try and answer. Um, thank you so much dot Political Think someone asked if you could week up that side when you're talking about Vietnam? Uh, you know, uh uh, yeah. I mean, is this slide you talking about? Oh, my. You're not sharing in the moment. I'm not sure. I'm not sure you know again, we tried sharing your screen. Uh, any questions? Please don't play the chapped or can under your senses. Well, can you see it? You know? Yeah, I can see. So is that it? I I think it was the one before, but this is the next one after that. So, yeah, just trying to see who asked that question. Now, is that a slightly talking about? Yeah. Yeah. So what we're saying is that oh, doctor shares certain from United States who had his theory and probably is correct. But he misinterpreted his own experiment Mathematically, he did it wrong. So, yes, In his case, if I'm guessing right, if you lose the leader blood, you're traumatized. You give the blood back, but you probably do need some extra fluid to replace the third space. The problem was quantitatively instead of saying it's I don't know, I'm guessing. No said this thing. You need an extra leader he was. Then you need an extra eight leaders. So people would be getting massively resuscitated or lots of fluid for their cardiovascular system. And that because in Vietnam where they have young, healthy soldiers, they probably survived, you know, improve their survival because of the resuscitated or circulator the system. But this the doctors it in Vietnam, but also in the trauma centers in United States, cause they were doing the same thing as the military found that Yeah, we're doing okay from the cardiovascular side, But this flu, we're getting so much fluid and believing when you saw this, I saw this myself off the very first time I was working trauma and I saw the qualities of fluid they gave This goes, I just thought, Wow, you know, in Europe you'd never get damaged fluid. And so the new illness that they were C was this pulmonary edema. So based what I'm saying is that if you give too much fluid, there are consequences if you don't give enough their consequences. But you give too much. So you're trying to get somewhere in the middle, and they're just saying it's trying to heal, you know, the consequences of giving excessive amounts of fluid. In this case, it was the overzealous admit, Stryker fluid causing permanent deal. Thank you. I think that did somewhere is what? We have a question from Lowell. I was asking, how do you, um how do you know how much fluid to get up during surgery when they have been no by mouth? For some hours? They had to be. Honestly, I can give you the shorter, long answer. The short answer is, um there are people that give, you know, say ah, as I said, take him to the top of the starting curve. So make sure your cardiac output before you start and then fill them and fill them until they don't fill them until they no longer improve their cardiac output and stop there so they lose a bit of fluid. You're always interesting. In fact, one of the talks third talk. I'm giving not tomorrow. But the day after the next talk will be on how to assess fluid responsiveness. But to be to be very honest, as I tried to fill in with those last line is you probably want to be somewhere between the two not too much, not too little. How you get to that isn't always easy, but there are ways of doing it. That's what we'll talk about the last of those fluids. Food talks get larger. We have a question from Hugh. Just got pregnant. Um, so with the shock long study, we gave luck that tainted ringers. Would it be different if we gave them quote Lloyd's instead? Would a shock long still be present? Or is it not be such know it be the same thing? Is that again what I said to you? It initially was. There's been for decades a debate between us and Europe. Crystalloid colon Europeans were colitis, and they never gave tones and tons of Coca Cola. The Americans. Where they said, basically, is that because on Lee, one quarter of Colyte stays start one quarter of crystalloid. As you saw earlier stays within the intravascular compartment, they were used to pouring in crystalloids that if I if I lost leader of Intravesical volume, the American model would say you have to give four li at least four liters of crystalloid to compensate that one leader because you're losing three quarters of the of the intravesical part. So in the in a nutshell, what I'm saying is that most people in Europe never gave 8 10 liters of excess fluid, and I say so they did. And that excess fluid, we almost always be crystal never called. I think the point is trying to make is that the whole point is not to get into too much in the history was to say that you know too much or too little is bad for you. So I think along the same lines of the virus asking, um, in the first case, I think he missed stakes. Do we give somewhere in the middle the first case, Any discounts? The cardiogenic shock case? I believe that's irony is not the case you're referring to. Yeah, yeah, Well, what I said there was that this was a patient who's margin for error was unbelievably narrow. I mean, everybody thought this guy was going to die, and the point was that as I said, it was very dramatic, because if we did nothing, he was going to die for sure. We had to do something to get him well enough to get him transferred to a hospital. that could give him a minuscule cancer, arriving by doing cardio coronary catheterization and to get him well enough. That was the whole goal, and no one thought he's going to survive this. We had to know when he respond to fluid or not. But the problem was given his circumstances. We were were saying his cardiac is starling current would be so flat, and he's so far to the right. If we gave him even a drop of fluid, he probably poured into his lungs. And if you remember the oxygen delivery paradigm that I spoke to about last time, that would drop his saturation and further with a low cardiac output, he would die. He wouldn't improve his cardiac output, but he get a lower saturation would kill him at the end of our future. But we had to do something. And so we thought, Let's give him fluid without giving him fluid, and we didn't really lifted his legs, and I said, We'll talk about that the next lecture to but that's a way of transfer. You're infusing some fluid, transfusing somebody with their own blood, and if it doesn't work, you lower the legs you've gained and lost nothing in his case to my other. Amazing. I must confess I was totally surprised. Is cardiac up? It massively increased. So he was definitely responding to fluid. So his card, his starling curve was not flat as I thought it was. It was it was quite steep. So that was great. And he went to the cath lab, and he was. They found the art of the coronary artery was was blocked off in the state. That so? That was a good safe. Sometime I see someone's, um, muted themselves. Is that because you have a question? Yeah. Yes. The pressure in the boy that you people survive meeting to survive by lifting the leg. Yeah. Um, they called the cough the most off the cuff off the leg, the two legs, their second half. Those are don't know. Head where some blood more. Oh, yeah, But he was He was not pumping any blood. I mean, his legs were He was flaccid. He was intubated. He was ventilated. He was. This man was hanging on blast, you know, but his fingernails, Um no, that that's I mean, when you're walking, you have course it does it helps a bit, but we're talking about someone who's lying in the bed, who's totally immobile. So he lifted his legs about 45 degrees. In fact, there's a whole technique to it, but I didn't want to go into. I will talk about that in next lecture to. But in this case, I just wanted, you know, just explain to you that sometimes you you're not sure what how someone's going to react to fluid, that's all. In this case, it's stages. Like I was totally surprised. I didn't think he would react with fluid. I thought getting food would kill. And so I'm just noticing a little straighter. Okay. Thank you. The memory. Your question was answered by Dr Phil. And just now, when he was answering the Russian about So she was asking how much did you raise that you mention? It was 45 degrees. Does anyone else have any questions at all? Feel free to meet themselves or again, drop it in chart. Um oh, we've got one from Lona. Why do you get a high BP reading? If you checked on legs compared to a young ah ah, that's a That's a really good question. So it's not if it's kept on your legs. It's kept on your legs if you're standing up and if you want. If you want to make some money, I always do this with the register residents I was with. I make him a bit, you know, you buy me a sandwich for lunch. What's your BP? I'd say they say, Oh, it's 100 20/80. Okay, I'm gonna take it at your ankle. Which book is going to be? Oh, it's gonna be also use lower or they'll say, Oh, it's 1 30/80. Okay, write down on a piece of paper what I think it's gonna be and they write down where they think it's going to be, and I would write down. So let's say that's 1 2080. Okay, I'd write down is going to 240. So we take the BP and it comes back. It's 24 because your BP is measuring your BP, but also it's a calm of blood and, you know, like any call, um, it's gonna have pressure, too, and that's why if you take it standing up, it's going to be very, very, very high, and there's a very practical There's a very practical aspect of this. I remember I once got into a fight with the surgeon. Why? Because he was doing breast surgery and he liked his patients to be sitting up at about 70 degrees, and he had the BP cuff on Hey, didn't want it on the arm because he felt it bothered. You want it on the leg? And I said No. And the reason I said no, it was for exactly that reason, because there was a case where I was working where, uh, somebody a woman was having minor breast surgery. They did exactly what I've destroyed and he didn't wake up. And it's perfectly logical because the pressure that you're caring about when someone sitting up is the pressure in their brain. And if you take it at the ankle, you're going to get that call my blood so you can have a blood work. It's relatively high, or least okay, but the pressure in your brain, which is above that is gonna be very low. That could be very low. So I said to her, I said, No, I'm not gonna do that. And he wasn't happy, and I wasn't happy. And we both decided not to work with each other. But, you know, try it on yourself, get a BP cuff, put it on your ankle and stand up or not to you do to somebody else and say, Write down your BP. Do it when they're flying flat. What's your normal BP? It's 1 2080. Okay, I will bet you I don't know a couple coffee and you write down on a piece of paper. What do you think It's gonna be standing up, okay? And you put it on the right ankle, and I'll bet you'll be 220 to 30 every time. Hum plans. Um, next question is from Marines asking d also need to give somewhere in the middle for hemorrhagic or septic shock. Ah, request it will. Uh, those are two different types of shocks. So hemorrhagic Chuck, you are hypovolemia and you're 10 to be vasoconstricted. Okay, septic shock. Remember, we saw about the glyco. Okay, Alex. And how you lose the production of nitric oxide. And you you lose the control. Your very dilated I was gonna talk about this the next talk, but I can give you Ah ah bit of a taster if I So let's say your BP is 1 20/80 okay? And you're healthy and you're young and I start taking blood off of you continually. What's the very first thing you're going to see in your BP? As I take Maura more and more and more and more blood reduction of your BP? No. Your first thing you're going to see is your diastolic BP is going to increase. Your systolic pressure will stay the same that I'm seeing the very first thing, which means that your pulse pressure gets smaller, but the diastolic goes up because you're vasoconstricting and vasoconstricted is one of the aspects that determines your diastolic BP. Now let's say you've got someone who's got septic shock. You come into the accident since department and their blood pressure's say, 75/38. Well, right away, I would say to myself, That person is septic. Why? Because if you're dilated, as opposed to constricted, your diastolic pressure drops. So it's a person who's in septic shock, has a dilated vascular system, so their diastolic pressure is low. And somebody who's in hemorrhagic shop, at least initially tends a high diastolic pressure because you're vasoconstricting when you're trying to compensate. Speaking of your young and fit. So the difference treatments are different, I think is much. Next question is from up the largest, ask him would pushing the patient on to their back on but circling what quickly could also do the same thing regarding can't project out. But I think this was last. When you question before when you're explaining the, um, BP readings. Okay, I'm not sure I understand that. Yeah, if you think I don't know if you can, um, elaborate. Well, so you know how the movies about lifting their legs, Um, whether they because it will also pressed a patient back. Yeah. Okay, that's a very good question. So, um, I didn't want to go into, um too much of the detail how you do that. It's a very important technique. If you do it absolutely correctly, the person could be at 45 degrees sitting up and their legs are flat. And what you want to do is tilt the bed. So there they're thorax is flat on their legs. A row reason is your, um your, um, in court, you're not incorporate What's weird thing? You You're mobilizing your your splanchnic vessels as well. So yes, you can just lift the legs, but to get the most blood if you like, you gotta do flatten of thorax, Lift the legs at the same time. So the detail I don't wanna go into details that it wasn't the point of this talk. They'll be we'll talk about another section. But the point was just that, you know, that was the That was the point. Was that you? Never You never Sure. Whether someone needs more or less fluid. That's why I'm saying, Well, we'll talk about the details that next, but the time someone on make themselves just now I'm sorry I interrupted you. No, thank you. Um, no, thank you dot Struggle. I think you said you don't want to go too. Too much detail. I think there was a question asking why raising the leg helps called back up. Well, raising your legs, okay, Do, simply if I raise my legs, um, your auto transfusing something of the order of 300 mL of blood into your It's your heart. I'll tell you where it's again. I didn't want to go into this now because I have a couple other examples. Clinical examples that will, um, we'll talk about next time. So I didn't want, you know, I don't know. You know, you won't want to come to the next lecture. I tell you, I'm dozing, um, increased venous return. Yeah, you're increasing the nystatin. Oh, I hope that answers. Your question is an expert next lecture. We're gonna go into detail about the physiology of venous return, which is often very brilliant. So don't worry. We'll answer those questions, so I'm any other questions here? That was the last one I saw in the chart. Um, I have for the feed metformin. The chance for a couple times, please. Do you feel that out? Um, I am aware of kind of slightly one over Aziz. Well, but thank you so much. You're staying on the local. Um, so, yeah, this would be like, a bit of change. Too often Questions, if you do have and again, please brief. Feel free to on me years olds doesn't seem like they're hiding the questions. Thank you so much. Up to my goal. Um, before taking your time out of your Friday night home to teach us today and Gangelhoff Banky's in. The challenge is large and if you can see them, but it's very appreciated. Amazing. Exaction. We'll see you all tomorrow. Right? By the way, for around two around three or Yes, I think you I believe you said it was like to the four in her toes. All right, well, I did one on oxygen delivery. That was a doctor. A lecture, As I felt That feeling of the heart is the commonest thing you're going to do. Um, and it's something that's often not really well understood. At least the people I've worked with, I'm going to spend it. A total of three lectures on filling one on the consequences. One on the physiology and the third one on how to actually assess. And if you don't understand the physiology, you understand how the assessment works. And after that, we got the lectures on acid base and hyponatremia. You know, different Anything. You could wait for the next session, Teo, but yes, thank you so much. We won't keep you any longer. Have a lovely rest of your home. Uh, we hadn't. I mean, I don't know. We'll see you tomorrow, but enjoy the must be a week and nearly, um and guys, I'm just gonna put the feet back one more time. So please do start that out. Um, so you can use it if I have a tendency and also appreciate feedback as well. In General Onda. Yeah. Pleased to join us for, um, sessions tomorrow. Let me just check what the first one is starting at 10. AM tomorrow. We have talk about contraception from Doctor Jonah Kirkcaldy. We'll be posting the time people assume usual in there. 11 chance. But you Thank you so much. Um, actually, go again. Thank you. Hi. Thank you, Professor. No. And the cool in about a minute.