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SICS EVENING EDUCATION UPDATE - vvECMO, Dr Ian Scott, National ECMO network

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Summary

Attend this educational evening update to learn from Dr. Scott from Aberdeen Royal Infirmary and the National Respiratory Echo Service on ECMO (Extracorporeal Membrane Oxygenation). This session will cover the technology and physiology behind ECMO, indications based on the UK network, evidence, background on findings during COVID, the data in Scotland since ECMO service was commissioned in 2020, and case reports. If you are a medical professional, this is the perfect session for you to stay up-to-date on ECMO as a life-saving technology.
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Description

Ian Scott, Clinical lead for ECMO from Aberdeen Royal Infirmary, will join us to give us an update on all things vvECMO from the nationally comissioned network service.

Learning objectives

Learning Objectives: 1. Identify the components and functionality of a respiratory ECMO circuit. 2. Understand the potential problems associated with the use of ECMO support. 3. Explain the indications for ECMO use in the UK network. 4. Analyze the data and evidence related to ECMO outcomes since the service was commissioned in Scotland. 5. Describe the safety challenges encountered due to COVID in decision making regarding the need for ECMO.
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The following transcript was generated automatically from the content and has not been checked or corrected manually.

Hi, good evening, everybody. Welcome to the June SI Ts education evening update. Um And we are delighted this evening to welcome Dr Scott from Aberdeen Royal Infirmary and the National Respiratory Echo Service. Um to give us an update on all things ve um just before we begin, uh the Scottish care know many of you will be members. But for those of you who have, who are joining us for the first time, SI CS is an organization which aims to improve the care delivered to critically ill patients throughout Scotland. And really we focus on free areas, education, research and audit and, and there are a variety of categories of membership available on the SI CS for SI CS. Um And there's a number of benefits that come with those including reduced membership, reduced attendance fees are in annual ad and meetings, comprehensive transfer insurance for anyone that does um uh transfers and there are various education and travel bursaries as well. So if you're interested in finding out more about SI CS and then please have a look at our website. Um So just introducing our speaker for this evening. Um So Dr Scott is a critical care consultant in Aberdeen and he is the clinical lead for the respiratory ECMO service for Scotland. He became a consultant in 2015 after graduating from the University of Dundee in 2005, and he undertook most of his training in the northeast of Scotland and, and spent additional time at the to gain experience. He's also worked for Sydney. He just after CC and has got experience in retrieval and prehospital medicine. He tells me he has a long suffering wife who puts up of them disappearing, uh, on retrievals at all hours. Um, and he's dad to two very awesome little girls and outside of work he enjoys outdoor pursuits and, and he plays a sport called underwater water hockey, which we were just discussing, I've lost about 20 minutes to Googling. Uh, so, uh, if, uh, we're so delighted that you're able to come and chat this evening, do Scott? And I'll hand over to you. Um, if you'd like to ask any questions, you can pop them in the chat box on the right hand side and we'll pop them to him at the end of the talk. Ok. So, um, thank you for inviting me to speak to yourselves tonight. Er, hopefully you can see my slides. I think I can cos I can see that screen. So what I thought I would try and talk about today, er, see if my slides when I move on. Er, was basically what is respiratory ECMO? Um in terms of a bit about the, how the technology works. A bit about how uh you can figure a circuit, talk a little bit about the physiology related to ECMO and some of the problems that occur between the patient and the circuit and that kind of interaction just for a bit of kind of background go over the indications kind of set out in kind of the UK network about what we kind of think would benefit from EC O and what the sort of criteria that we work to is um cover a little bit about the evidence. And I thought I'd cover a bit about the background of sort of VV originally where that came from in terms of commissioning service and what that was based on and touch on a little bit about what happened during COVID because I think that kind of maybe hopefully just explain some of the difficulties about decision making and kind of a new um pathology and how as a network, I guess we probably did struggle a little bit about trying to work out who would benefit from EC MO and who wouldn't. Um and how to undertake that. I thought it would be useful maybe to cover a little bit about since er Scotland actually commissioned the former ECMO service in the beginning of 2020 what our data and stuff has looked like after the last three years. Um and discussed a little bit about that just from information, just discussed about the UK network and how it's configured. And I've got a couple of cases and I'm sorry for the people who came to the SI CS and heard my talk before they are the same cases and partly just because of the permission, I got to discuss those cases. So I didn't really want to put cases after I hadn't got kind of formal consent from the patient. So they're kind of why I pick those cases more than anything. But I'm happy to kind of talk broadly about other either referrals or cases. Um you know, at the end, if that's helpful for people and gonna happy to take questions um throughout if need be, um I just make sense, I can see the chat, I suppose just so that if anyone does ask question, I can try and just answer that as we go. So I guess there answering in the first part, what is kind of ECMO? Well, essentially what it is is just removing deoxy blood from the patient and then passing it through a oxygenator using a kind of a centrifugal pump to basically drive the blood through the oxy and back into the patient. So it seems on the surface, relatively simple and essentially the technology that has been developed over the probably last sort of 20 or so years has really allowed ECMO support to um increase from a something that's quite difficult to deliver. And in terms of cause lots of problems in terms of damage to the blood itself and its blood cells to something that can be provided for prolonged periods of time. Now, people can be managed on eco support and you know, obviously the case reports and people have been supported for, you know, over almost a year now, I think on extra corporeal circuits. Now, whether that's the right thing to do or not, it's a completely different debate. But the technology has developed in a way that allows us to provide prolonged support for patients. Um If they've got er particularly what I'm discussing respiratory failure, but obviously can be used in the context of cardiac failure as well with slightly different configuration. So the divan in technology have really allowed that to happen. And I guess one of the key components of that is the pump itself. And again, something that when you pick it up looks relatively simple in terms of these kind of little veins and things within this plastic container. But essentially the design of it has actually allowed us to support patients in the way we can. And essentially, if you look at the pump itself, there's no bearings in it. So there's no bearing surfaces that have contact with blood, which often cause lots of problems previously. So this is essentially a magnet that floats in a magnetic field. And then you provide a different kind of magnetic force to it to make it spin. And these veins and things are designed in a way that will basically suck the blood in and then push it back out of the pump. And even these kind of gaps around the side are key to allowing effective movement of the blood kind of a sort of fluid dynamics. I mean, interestingly enough the sort of pump technology, the optimal flow through this is probably several liters. And actually when you drop to a lower flow, you actually get internal recirculation within the pump head itself, which can cause damage to blood cells. So often the belief that if you're running very low flow that's actually safe may not actually be the case. And this may explain of the reason why things like extracorporeal CO2 removal may not been successful as people had hoped for. Because often they've basically adapted kind of ECMO technology with high flow and made it go lower. And this can actually potentially cause worse like hemolysis and damage to things like your clotting factors at running at very low speed. So it's kind of designed to run a, you know, a specific kind of blood flow. And if you drop below that, that becomes a problem and if you go above that, it can also become an issue. So um this kind of technology has really allowed um ECMO to be much more successful. So these kind of what appear relatively simple um devices are actually relatively important for the ability to provide prolonged ECMO compared to things like previous roller pumps. So that's one of the key components in the circuit is the pump itself. Um There's different types on the market. Um We use a LEVO tonic system in Aberdeen, but there are different types of ECMO pumps, but they all work very similar in using this kind of technology. The next uh component to the circuit, which is key is the oxygenator itself. This is going to be our membrane lung, which is basically works in a very similar way to your normal lungs. It allows oxygen to diffuse from the gas side into the blood down, essential your concentration grade and CO2 to move the other way. So it's a polymethyl pen type sort of fiber, um which allows the gas exchange to take place. So it's what that basically is, it allows movement of the gas but doesn't allow kind of fluid to shift across it. And it's basically contained within this. If you unwrap it, it's got a huge surface area. So kind of a bit similar to the lungs, um is how it works and they even have similar kind of problems that start to occur with them. You can get essentially thrombus forming within the blood side of it, which would act a bit like having a pee in terms of gas exchange. So you'd have bits that might be ventilated, for example, but not perfused, you can also get um areas that are essentially perfused but not um sort of ventilated. So, condensation of the can start to form within your oxygenator, which can affect gas exchange. So they sort of have an aging process to them. So when you first go on, you probably have the best kind of a gass exchange that you have with the oxy. And as you kind of move through its life, they then begin to fail. So you can get thrombus forming in them, which can produce gas exchange, you can get condensation and things forming in it and the ways to kind of, you know, kind of mitigate against that such as this kind of anticoagulation you use and also methods to try and push out the things like the condensation that forms in it. So when you first go on, the oxy usually works pretty effectively but has kind of a life expectancy and that varies depending on lots of patient factors often early on. If you've got someone who's um very cat, um so inflamed, then they sometimes you find the oxidation may fail more rapidly than someone who's less inflamed. Um Also problems with, if you start developing thrombus within it, you can get um issues with failure and they can sort of appear in a number of different ways such as we measure the pressure across the oxygenator. So you can get an increased pressure gradient, which might indicate your oxygenator beginning to fail. You can get changes in gas exchange or probably the most common one is you see changes within the sort of coagulation state of the patient. They might start bleeding. You might see drops in things like fibrinogen, which might indicate you could of failing, ate it. So you might need to change it out um, during the run. So they're the kind of things that once we're on e when they sort of come back to us is that we're looking for daily and taking various blood assessments for it and measurements of the pressures across it. And we sometimes decide we need to change them out. So um we end up cutting away a circuit and replacing it with a new one predominantly for the oxygenator part of it. I just taking that in a little bit more detail. That's kind of what it looks like on the inside. You've got gas on one side of membrane and blood and you've got um gas exchange across it, you can run it sort of countercurrent, which theoretically make it more efficient. The important thing to remember essentially is that what controls oxidation in an echo circuit is the blood flow. So that's how much blood you're removing from the patient and putting back into the patient. And so essentially, if you have an oxidation issue, you need higher blood flow to compensate for that or you need to try and manipulate potentially consumption. So that's how you oxygenate it. So your blood flow is very much like your peep and your F two on a ventilator opposed to your carbon dioxide, which is actually very easily dissolved in blood and can be removed, relatively easy with relatively low actual blood flow. Hence the reason why CO2 removal doesn't need such big pipes and blood flow. But essentially that is controlled by the flow of the gas through this side, maintaining a low concentration gradient. So therefore more diffuses out. So if you reduce the amount of flow coming through here, your CO2 builds up on this side and you kind of ripple it out and you don't remove so much CO2. So we talk about sweep gas. Um and the flow of the sweep gas is basically controlling our CO2 and our flow of blood is controlling our oxygenation in our patients. Um We tend to in sort of VV, ECMO tend to run 100% auction through here. Um We occasionally blend it for um a couple of different reasons for maybe you're weaning and things. But generally speaking, we tend to keep this at a kind of 100% and discuss the kind of physiology that kind of explains why you can get away with that really. And you don't end up with very high kind of um pa O twos and things. So they're the kind of the key bits of the circuit you have the pipe piping in between it. Um And then you need some form of interface with your patient. So in terms of cannula, and there's different ways you can cannulate patients. Um So you've got a duel lumen sort of configuration whereby essentially this puts the blood in and takes the blood out. Um And you're basically going to suck blood out of the superior vena cava and the inferior vena cava and then inject it back into the right atrium. So, you know, the different ones, these on the market, but essentially, you know, relatively large bore cannula for an adult. So an adult male, you're looking at something like 31 or 32 French type size Cannula, um other configurations you can go sort of in the femoral vessels, which most people will be aware. That's what we kind of do. So we use a fem fem. So we take the blood out of a femoral vein uh using a cannula like this, which is called a multistage cannula. So it can basically drain from the tip and also down its, you know, relatively large part of its length. The advantage of this kind of multistage approach is you don't have a single point of suction. So therefore, your overall negative pressure should hopefully be a bit less. These can still suck on to your Vena Cava, remembering that you're in a relatively compliant vessel and therefore the vessel can stick to the cannula and that can affect your flows and things. So again, that's another thing you end up kind of have to managing and trying to balance how much flow you want against. What you can actually weird is achieve without causing sudden drops in flow. So we may opt to have maybe a slightly lower saturation systemically, but with a more consistent flow and know we're not quite matching cardiac output as best as we might want to, but we can achieve a safe flow and actually a safe option delivery return Cannula just has a base ear holes at the end. Um It's got a couple of holes on the side, but predominantly at the end. And this, we're gonna place in the right h or as close as we can get to it. And again, there's other manufacture and you can a short a canyon if you go for like a fem jug. So you might drain from the femoral vessels and return into the internal jugular depending on um sort of preference. And also maybe, you know, access in terms of someone has a no access to a femoral um vein. You may have to, you know, on one side, you may have to go fem jug. And if you had, I guess no femoral access, you might end up being, you know, forced into using something like a bica or type Cannula in terms of benefit one over the other or which configuration is better. So I guess this is the configurations you've got there probably isn't a huge amount of difference between which one you go for. So thought that this duel lumen can, you would be maybe a, you know, beneficial in a sense you got one side of access. Maybe you can mobilize more easily because you're just using a neck. But in reality, that's not really been shown to be the case and you can stand people up with fem fem configurations, You know FE M jug, I find this 1 may be a little bit more just cumbersome in the sense that you've got pipes running from both ends of the patient. But generally, it's more what your center is used to and you can basically mobilize people with this, with this method or this method. So we pick this fem fem configuration because we find it's relatively straightforward in terms of cannulation, you're not often fighting with someone using the neck as well or up that end, you can just stand in one place to access it rather than having to use two sites. So that's why we predominantly chose it. Um There are other cost implications for using something like a duel lumen Cannula over the, the single cannulas. But essentially in terms of patient benefit, there's probably not much to choose from it. So that's the kind of circuit and um how the circuit is kind of set up. So I guess the next thing to kind of think about is that seems really straightforward. That makes a lot of sense. You can someone surely this would fit for a lot of people with respiratory failure. And why would we not do it for basically everyone, why an artificial out internal lung seems a great, you know, idea. So that what's the harm to it or why would there be problems with it? So I think what I like to think about ECMO is this kind of complex interplay between the circuit and the patient. And you can broadly split them down into, I suppose, three different areas. So I put the blood up as a an indication of what's gonna happen with components within your blood, probably not red cells predominantly. Now with kind of modern technology don't often get hemolysis, we don't routinely even really check for it um in terms of breakdown factors, whereas previously you probably would have done that. Whereas so hemolysis isn't a major issue. It's probably more to do with interaction with your clotting system. That is probably the biggest interplay in terms of blood with the circuit. That is the biggest issue. What I mean by that is that as soon as that blood comes out and goes on to the um circuit, it's basically a foreign substance and it's immediately trying to trigger um a clotting event in the patient. So you try to be on thrombus. And even if you got circuits that are more cleverly designed in terms of having you have heparin coated ones, various sort of protein coating ideas, all sorts of things people have tried. But essentially you are always fighting this in ability of the body to try and to thrombo once it comes into contact with a foreign surface. So you have to take um me to try and reduce that. And while circuits have got better, that still is a problem. And again, the longer you're on, you start to damage your clotting factors, particularly things like Von Willebrand's factor. So you almost get like an acquired Von Biran def deficiency, which can lead to a coagulopathy. And as soon as you start forming thrombus within your circuit, whether that's in the piping, which is less common but can happen. But within your ate because of it's, I guess smaller size of um where the blood's running through and it's more likely to sort of cause a thrombotic event. You start getting thrombus fall and then, and it becomes a vicious cycle. You start getting platelet aggregation, you get the platelet plugs and stuff, start consuming your platelets, you start consuming clotting factors and then you start to bleed systemically in terms of the patient itself. So you start seeing them bleeding around lines and things like that caused by the fact you're consuming lots of clotting factors. So again, daily you're checking for this, we're looking for signs that's happening whether that's examination of the circuit, but also in kind of blood work. So you can kind of get an idea in terms of fibrinogen, often drops. And that can usually be a sign that you're getting consumption platelets again, are usually quite a good marker. Um If you start dropping your platelets, the concern is, is that circuit issue could be other things. Like it's quite common that you end up having or thinking it could be, but often it's actually just the circuit itself consuming um your platelets and again, removing the circuit usually solves it. So in those instances, we would cut away the circuit place a new circuit and obviously that would cure the bleeding issue. Often you find if you just start giving lots of factors and things, you're just chasing your tail all the time. And sometimes by just removing it can, can be the cure to it. The other thing that in terms of, I guess blood is that it does cause an immune response as well. So just going on to ECMO actually is hyper inflammatory. So just the ECMO itself can cause essentially an inflammatory response and that can vary from patient to patient. So it's another, you know, consideration actually going on to ECMO, are you going to generate some inflammatory, you know, process? Um Is that going to be a problem or not often it's not a huge problem. Um But it's something to also, to be aware of that. Actually, that going on to ECMO can be sort of hyper inflammatory. The other interactions in the middle. One is kind of mess off is the drugs, is that what does the circuit do to your drugs that you're giving? And this is maybe better understood. There's been some work particularly like in a team in Australia, looked into this and looked at what drugs are consumed by the circuit. And that's partly probably mainly due to the kind of protein layer that forms in your circuit will start to bind drugs to it. So the ones that are commonly used by us in terms of sedatives to think about, yes, they are bound to the drug some more than others. FentaNYL, for example, is very heavily bound by the circuit, maybe morphine a bit less, but essentially they are bound to a to a degree. What does that mean? Well, essentially, it often means you run higher rates of sedation because you're binding it into your circuit. Um So essentially because you're targeting, you know, a sedation level, essentially you're titrating to that how you want, how safe you want the patients, you end up just running higher rates which some people can think like I'm running, why are they running so high Alfentanil or Midazolam or prof whatever? Um And the patient is still a bit awake, but it's actually because the drug is now basically, basically increased your volume of distribution, it's being taken within the circuit. So you just to be aware that that happens. Um So they're one class sedation, we basically to date to a clinical effect. So I guess it's not so important really. Um, other ones, Heparin is bound to it as well. But again, we're targeting a specific measure. So again, you want slightly higher HEP and ECMO patient to a normal person to have the same effect because of this increased polym distribution. Not such an issue, I guess antibiotic class is the one that's making the more concerning is if you are basically your antibiotics get taken up by your uh circuit, are you actually providing a therapeutic level of it? Well, it's been shown that probably most antibiotics actually normal dosing is fine. The carmine, you have to be slightly careful that you probably want to aim for the higher level of those drugs because they are the ones that are probably the most consumed by your circuit. So it's just to be aware that that drugs um get consumed and it also varies over time. So depending on your age of your circuit will affect this as well. So, and the other thing is when you come off ECMO, at the end, you totally take away this circuit. Um And again, you can, you may need to adjust things just after it. So it's more of an awareness of it in terms of clinically, how does it affect us? Probably not hugely because most stuff we're actually targeting um to a patient effect which you can either see in them or you're taking drug levels for it. Um, but there are just to be aware that that's what happens. And then you've got basically a sort of complex interplay with the patient's own physiology. Um And I'll go into that a little bit more detail, but essentially, um, you know, you got your cardiac output and then the factors go with the circuit. So I'll just cover that in a bit more detail, um to try and explain it in more detail. So essentially, if you think oxygen delivery with no ECMO, um essentially your ventilation through your lungs, you do have some shunt and varies depending on disease states and things. Um And then obviously you got your oxygen in your blood, which you really want to think about oxygen content of that and then into play with cardiac output and ox delivery and sort of at rest and stuff, your oxygen delivery to oxygen consumption is a ratio about 5 to 1. Um And if you actually get your way, you want to maintain that ratio always at kind of like at least 2 to 1. Otherwise you will tip into kind of anaerobic respiration. So um these are things that you kind of try to try and balance that once you have the ECMO circuit on to it. So people have kind of worked out roughly what your oxygen consumption is within kind of critical illness and it does go up with, you know, things like sepsis work of breathing all those sorts of things. So once you start thinking about having the ECMO circuit on this is an area that we can potentially manipulate. Um And then obviously, your CO2 production is going to get taken out by your lungs again. So that's kind of simplistically how um option is delivered normally. Um probably knows that hemoglobin is probably the biggest component in terms of your saturation of hemoglobin is going to give you a most oxygen delivery. And obviously, we know in critical care that actually transfusing people doesn't appear to empire massive or isn't beneficial in the way that you would hope it would be. And I suppose that's something that in ECMO, I think has probably changed over time when, when I first started doing ECMO, we were targeting hemoglobins of 100 120 routinely. Whereas now we've realized that actually you don't really need to do that and probably taking and the problem is the evidence base in a different group, but actually is the transfusion actually beneficial. So, yes, sometimes I guess we will maybe target a high hemoglobin if we've got issues with oxygen delivery. But generally, we'll try and see if we can get away without doing that. So if we add the ECMO circuit onto it, what are the sort of things that happen? Well, ideally what you would want is that I would be able to remove all the deoxygenated blood from the right side of the heart, send it around my perfectly designed oxygenator, which would give me 100% oxygenated oxygen coming out here, which would lovely feel straight through into my right ventricle and would come back around here 100% saturated. Now, clearly, that's not what happens. So we are often just taking the blood out of the inferior vena cavus. So remember your blood coming back to your superior vena cavu may well actually have a lower saturation that's going to mix in here. So giving you this mixed content, which is going to be lower. My cardia output could be six liters and I could sit there at six liters thinking I've got a perfectly matched system, but in reality, there's gonna be this fraction. So some of the blood that comes back is gonna come straight back around my circuit and come back in here. This adds another area of kind of complexity is that my, now this has got oxygenated blood coming into it. So now my saturations here are higher. This essentially becomes I have less ability to deliver oxygen. So actually my oxygen delivery becomes less. So this circulating fraction, you have to kind of try and you know, if it becomes a big issue, try and deal with that by either change your cannula positions, change of additional cannulas or something. If you're trying to reduce the pressure, um you know, recirculating blood can be a sign you're getting right heart strain and possibly, you know, issues with your right heart. Um, if you can't sort of pump it forward effectively, so that can be a sign of right heart dysfunction, rather than just a cannula problem. Then you've got the interplay of your lungs. You got a, a guess on the, you may have a completely no, um, native lung function or you could have some lung, native lung function or potentially getting to a point when you got predominantly your native lung function, do all your ventilation um during your ECMO run. So it's just working out how much is provided by your native lungs. And you know, maybe you've done a bit of weaning and things and the patient is beginning to improve. And then if something happens to their lungs, they suddenly become profoundly what appears to be hypoxic. And that's because you're now no longer matching the amount that they need because you were actually providing some from their native lungs. So often we see that in a patient that may be beginning to wean and then maybe has a complication, such as a bleeding complication to their airway and you lose a native um lung component. Um And then you may need to try and increase your ECMO support the other bit that sometimes we might end up manipulating is obviously delivery and obviously, ideally consumption. So if the patient has got a high amount of oxygen consumption may be there, you turn the sedation down and you're suddenly struggling to match it because they've got a high work of breathing. You may need to consider whether or not you need to be sedate them at that point. While you allow for some more native lung recovery, if you can't quite match it with your circuit. So you have to kind of play with that, you know, that situation as well, that some patients you might be able to have fully awake and they are fully ECMO supported and have no lung function and they're fine. Other people have a higher um oxygen demand and you can't deliver it by your circuit. So therefore, you have to maybe try and reduce this. So things that we can do simply would be, you can call the patient through the circuit. So you might reduce their temperature to try and reduce the um oxygen kind of consumption or are essentially, you could obviously sedate them more, you could paralyze them that might help with things like worker breathing. And certainly I've seen that in patients where actually it looked like the oxy could be failing because suddenly they had, they weren't, we weren't quite able to have, you know, high SATS coming out of OXY, but actually they had a very, very low um saturations pre oxy and actually by just sedating and paralyzing the patient, this increased and then OXY was still actually working reasonably effectively. Uh It was just increased consumption that's causing the problem you can suppress the cardiac output. And it's kind of a double edged sword really you could that will often what appear to improve your oxygen saturations in your arterial blood gas, but you will be reducing your oxygen delivery. So it's kind of a careful play if you decide to manipulate. So sometimes we will start um like asthma or something infusions to dampen down kind of high cardiac output um state. But you have to in context make sure you're not suddenly providing essentially not enough oxygen delivery. You know, if you start getting a rise in lactase or something, then you might be worried that you're not really achieving what you want to with that strategy. So there are different strategies you can manipulate cardiac output, you can manipulate what you're consuming. You can try and increase your E ECMO um blood flow. That might be why putting another drainage cannula if you can't achieve it through the one you've got. Um there are stories in case what people putting additional oxidation stuff. And we used to do that when we had less efficient oxygenators, we tend not to do that that often because you can generate pretty high flow through the ones that we use. But you could add, you know, a different oxygenator to the circuit if you need to. So that's kind of a brief run through of, I guess, ECMO, a bit of physiology about it. Um And some of the issues that we kind of, um, have to deal with, um, with whether it's sort of bleeding complications caused by induced coagulopathy, managing your oxygen delivery from your circuit, I suppose. Then it comes down to the evidence for respiratory EMA and where does it come from? So you probably can't really read all these bits. They just kind of do like hints, ones to talk about. But the original ECMO comes from the Caesar study. So that's now, you know, pretty old study 2009. And did that really show emo as beneficial? We can debate this for a long time, but probably really showed maybe going to a center might be beneficial because actually not everyone got EC O went to Glen Field. Um and you don't actually have to have much crossover. I think one patient to make it a negative trial. So it didn't show a huge advantage to ECMO, but hinted that there may be some benefit to it if you look at that paper. Now, interestingly low, there's very low pron in both groups of the patients. So whether or not you would get the same result if you proned all the those patients. Now, I don't know, there's probably different other ventilatory modes that are used more such as APR V would that have an impact on it? And even patients within that group got oscillation, I think um more in the control group. So again, did that affect the control group in a way that the EC O group didn't, I don't know. So I think it provides some evidence but it wasn't absolutely clear and I think even from then there were the people who believe and the people who didn't, er, from that study, but that's probably the start of the point that really began to push that maybe EC O was beneficial. Um, I just mentioned the other big study, um, because the order did it in Ilia study. So this was a study in France more recently, which again, tried to answer the question, you know, as e more beneficial over the conventional, it was stopped early due to perceived futility. Again, there's lots of potential Christians with this study about their study design, there's lots of crossover, lots of people got ECMO in the control group arm. So you weren't probably testing what you think you are, especially doing sort of intention to treat analysis. I know it's been reanalyzed and maybe showed benefit to it. So again, even these studies haven't shown, you know, you know, absolute, it's definitely better than conventional. And, and that's probably the problem that ECMO has always sat is like, who would benefit from it, who wouldn't, who we better carry on conventional therapy? And I think some of those questions, we don't really have the full answers to, but there is some, you know, evidence out there that ECMO maybe infers um um survival benefit particularly in the more severe uh hypoxic group of patients. And I suppose the other thing is in terms of what evidence is there for lung rest. And is that what would really benefit is ECMO, really giving you the ability to provide very, very, um lung protective ventilation or essentially rest, um, the lung completely. And would that be beneficial? The answer is not really out there. I suppose the studies that tried to show did low tier volume, things like rest study and things using CO2 removal showed that yes, it was very possible to do that. But there were complications of the intervention now. Was that because rest uses CO2 removal. And as I mentioned earlier, is it the technology that we use? What's the issue rather than the theory difficult to know? But it hasn't been again proven clearly that that was um the best way forward. So how do we vent people on ECMO? Um What we do, we go to what we call rest settings. So we go to something like about pressure 20/10. Um And obviously just let the tide of volume but usually always less than six mils per kilo, sometimes none when you do that and then allow hope and lung recovery. But is that the right way to ventilate someone on ECMO? I don't 100% know. Um We often have actually moved to doing quite a bit more pron on ECMO recently. So we tend to prone most of our ECMO patients, certainly when we first get them and I use a kind of, do they get an improvement in compliance when I prone on echo? And then I might continue pron because I guess my belief or thought is that ECMO, you know, there's benefits benefits of pron which might be more than just oxy. Is that useful? There was a study done in the French group in COVID which maybe doesn't totally give us a clear answer either really that I was hoping. But it may be more clear. So that's the jury is out on that. So how she ventilate some we don't really know as a net, we're going to try and look into this and see whether or not full rest um and just side breaths on ECMO may be beneficial, but we still don't really know how to ventilate people on ECMO. And then, but the real ECMO, I guess benefit really probably did come in one of the first kind of H one N one or flu pandemics when appear to be clear, like Mrs or perceives viable benefit and certain case series and stuff did demonstrate ECMO did appear to be helpful, but again, no, not truly randomized control trials, but that's where the kind of wealth of um evidence started to build from. And then over the last however many years, you know, eco is being provided kind of in a a commissioned way within England for that period of time and then COVID came along and again, right back at the beginning, remember lots of network discussions about what we should and shouldn't do. Um but um you know, then data coming out around the world that may be very harmful wasn't beneficial. And we as a network with certain who we should put on, who we shouldn't put on. And, you know, there's been a couple of other studies that show that as the early in the pandemic, maybe more benefit as you went through the pandemic, maybe be less benefit. I think Allan from Pat was, wrote an editorial about maybe it's ECMO is, don't blame the technology. Maybe it's how we treat people when they're on it. Um They did behave very differently to other previous kind of uh pneumonitis is that you treated. So maybe it was our actual ability to treat people on. It wasn't as good as it could have been. I don't know, you know, maybe we've been more successful with, we had different regimes or treatment. We probably thought we were quite successful in wave one where we probably used a lot of steroid and stuff and people got better. Then we found that less successful as we went through the way. So then we kind of felt you weren't really had lots of people dying and things and really couldn't get people off. Maybe we didn't go long enough in some patients and some places went very long runs. Did finally get people off but how did they get on long term? We still don't really know. So it was, it was difficult as a network and as a provider, particularly us just coming into it, er, doing the referral part of it is who we should definitely offer heck mode to. Um, so that's some of the background evidence. So it's not clearly, there's not really good evidence that really helps, always tell who we should and shouldn't put on. And that adds to some of I guess the difficulties when people are referring. So just to zoom through a bit more before we get to some cases, so who to refer and who not to. Um It's kind of difficult if I'm honest in terms of answering this question. Absolutely. And giving you a perfect recipe about this person should definitely be referred and this person shouldn't be referred. And I think that probably is um borne out when you look at the data across all the UK networks across their time, they being commissioned. So obviously, the English network has been commissioned a lot longer than us and they still only have somewhere between about a 15 and a 20% conversion rate from patients referred, which would suggest that even after all that time, there's still uncertain because you would expect those numbers probably to come closer together in terms of referrals to actually taking the patient. If it was more clear cut, who should definitely be referred, but it stayed pretty much at that across certainly, most of the years I've been going to kind of meetings looking at data. So it's a reversible pathology of respiratory, which is obvious to say and we probably don't admit people to intensive care anyway, if they don't have a reversible pathology. But I suppose it's that gray area or borderline, maybe you might take someone and give them a chance, but you think they might not survive. And I suppose that EC A we're looking at, they probably should have a better chance to survive or due to kind of the investment you're putting into them. But it's difficult really to know where that cut off should be. And I think if you look globally, every country has a different cri you know, I guess that area where you're going to put people on is I think in the UK, we probably sit, add a more conservative where we put people on and that's, we reflected that our outcomes look quite good from ECMO and that might just be our patient selection that's causing that to oppose to, we're actually better at e um so be it has to be kind of severe type one respiratory failure or, you know, a combination of type one, type two respiratory failure or some like the asthmatic group who are just profoundly acidotic. And again, even that group is when you start nailing down into it, how much benefit does ECMO? Actually give because if you just manage that group, conventionally, they have a very high survival. You manage with ECMO, they have a high survival. So it's even trying to pick those out is not as clear cut. You look at the evidence base for it, Olia and things actually, you have to be quite hypoxic to get into it. So these are people who got relatively extreme hypoxemia. So po two is at 6 to 7 for three hours or so as the initial sort of criteria, po loa or a po two of great, less or 10 or less for kind of six hours or more. Um So again, relatively sort of hypoxic. So sitting up here at the top end of our management of A R DS, um so it still sits up here, I think, and I, I probably believe it's probably still up here. Um I don't think the evidence really supports putting people on who are less severely um hypoxic at the moment, you know, maybe that will change. Um But at the moment, I think it still sits up here and I think prone position and things um should come first and we should really try and make so we've prone to all our patients and give them a good opportunity to improve with that. Um You mu block moving up the the line. So I think it still sit up here. Um And I'm not really aware of any studies at the moment that going to really shift this in the short term, but I think it's going to sit up here. Um, and I think there's a bit of variation, people's practices from that, but look at the evidence base from it, it probably still sits up there. So what's the UK criteria, um, essentially taken from those studies PF ratio less than 6.7 for three hours or more PF and less than 10 for more than 10 hours. Um, the Murray score, which you won't really go into, but essentially this a way of trying to look at lung compliance, peak levels, chest x-ray changes, um and PF ratios so that I guess it takes out that you're not ventilating someone very effectively. Um You could give yourself quite a low PF ratio but um you know, they may not have the other features from it failed prone position. And I suppose that's also another one. We've, I guess it's difficult sometimes to always answer what is failed pro in position. Like how long do you have to be prone before you're failing? Truly say sort of six hours. I look for a 20% change in PF ratios to say maybe six, you know, that demonstrates pron success or pron may be working. Um But I suppose it depends what your starting point is to where you are. So and again, just because maybe you fail pron doesn't mean ECMO is needed, you know, if you're on the sort of 60 70% oxygen, you may not really feel those kind of PF ratios. Hypoxemia, you know, is ECMO going to be beneficial. It's kind of a bit gray area. So you might end up taking someone if they fail multiple times but not quite hit really the network criteria part or fail protective lung ventilation. So your peak pressure or your, your plateau pressures are high and you've got a large driving pressure and even we know that drive and pressure appears to have mortality associated with it is reducing, it actually improves outcome. I don't think the answer has really been answered in the literature. Um So again, you know, is e going to be benefit to a group of patients don't 100% know, but I guess we would probably push, you know, we probably would take people who are unable to be ventilated protectively. Um based on those thoughts. So just a bit about who we wouldn't take. This is more blurred. Hence I blurred the contraindications. So it's not really even, this is not as clear cut as it probably even used to be. So, I mean, no access, not the ability to be able to gain access is probably the key one. Like if someone's got vessels, you cannot access, they're not going to be able to get echo safely, but they're very rare. So I've had a few patients that have got missing kind of femoral vessels and stuff. But you can usually find a way of cannulated, whether it's fem jug or sometimes I had to go, you know, different, you can go like maybe the left side in the neck and all sorts of things. So access is often not um an absolute game changer physiological reserve, which is this diagram I put on here. It would suggest from the data that the older you are, the less P log reserve you have. But where that cut off is, is very difficult. And remember most of the studies only took people up to 65. So, you know, does that mean a 70 year old own benefit? I don't really know because they don't have a huge amount of data for it. 75 you know, 80 you know, where, where should that cut off be? Um So I think it's really looking at what do we think someone's biological reserve is um because you probably want someone who's got a reasonable amount of reserve before embarking on what it's probably going to be a long period of recovery, brain injuries and stuff like what severity of it? And think if you've got someone who's got clearly a neurological injury, that's unlikely to be, have a good outcome, probably offering ECMO is probably not going to benefit. But again, that's quite difficult sometimes to answer. Um and how you judge that and again, you know, that is difficult. You know, if someone's got something that could be reversible um what evidence do you use to try and answer this question? So, before it would have been a clear, no, now it's a gray area like most other stuff. So we have been, we have taken people with traumatic brain in and stuff and it's just the fear of like, could I do harm by doing this if I get to it conventionally, you know, which is gonna be worse. So again, it's that kind of balancing up bleeding disorders used to be pretty much clearly sometimes a now, whereas now actually quite good at managing the circuit without maybe anticoagulation or trying to manipulate um sort of clotting and things. So it's not an absolute, it's a concern because you're probably going to have issues if you try and run fully heparin free or things like that. But, you know, there are ways around it. So it's not an absolute no. So ventilation, how long, so high f two prolonged ventilation, high pressures, but, but how long is harmful? Seven days, 10 days, 15 days, all the studies pick seven days actually may be a bit longer is probably ok in certain instances, depending on how hard you've been ventilated. So again, it's another sort of gray area. So it's try and take that all into consideration, you know, when you take someone or do you get referred at day six, do you like, except a few more days of attempting prone position of certain things before you might then take them, do you then fall out criteria? What should you do then? You know, so they're the kind of dilemmas about these because they're just really unanswered in really the literature to help us, you know, terminal illness. I thought this was quite clear cut until probably the first, the weekend I had, you know, someone with malignant melanoma seems that on the face of it probably shouldn't take the person. But now we're using biological drugs and things that can suppress these diseases for a prolonged period of time. So, could that person benefit from it? How can I find that out? You know? So do you take a punt on that sort of patient or do you, do you not, you know, what's he going to affect that person who's now, you know, maybe heavily immunosuppressed you is my circuit going to cause more harm than just trying to manage them conventionally. So these are the kind of dilemmas that aren't answered clearly in the literature. So as, as a question here, so it does seven days cut off include duration of NIV two. Probably, I think in COVID, I would say we started really getting concerned about things like NIV use. Um And how much sort of self induced lung injury had happened. And I think we were then counting that in it. In reality, it's difficult to really know. I think if someone has been really heavily ventilated NIV for a prolonged period of time, then that must probably weigh in something to it. Exactly how, you know, strict you're gonna be on. That is a difficult one to answer. I think it will be in the context of the patient itself. I suppose my question would be is why did someone persists with NIV for a very long period of time before opting for intubation? If you felt that patient was a candidate to be intubated. And I guess my feeling was in people with kind of pneumonic change. A I is NIV beneficial over intubation. And again, we probably could debate this for a long time, but I would have thought possibly have some bearing on it. I wouldn't say it's an absolute cut off. Um, maybe in COVID, we were more strict with that and that was partly managing. Um, you know, fears of actually the survival rates weren't actually that great. And we've seen those people having very, very stiff lungs that didn't seem to get better. So I don't think it's an absolute, but I think it is important to consider what ventilation they may have had prior to intubation. And I have to say we don't get many. Um, um, so in terms of any concern of self induced lung injury on NIV to put on. Yeah. So that's the concern, you know, do they have a self induced lung injury that's going to be an issue in terms of their ability to actually come off ECMO and then come off conventional ventilation in the long term. And I don't think again, there's little evidence um to really help us with that. So that is our concern. It is a self induced lung injury that you just don't know how much harm you're doing. What the, you know, pressure gradients across your alveola are hope that answers the question. So no longer a definite. No. So, um what I mean by these funny pictures, I put up so neurological things, as I mentioned before, probably not an absolute no, particularly sort of brain trauma and things we've put people on um with that and we've had some success with it. There's always the fear of them bleeding into the head and you making the situation worse. So we, you might try and manage a bit more conventionally before you opt out. But then it's a balance between whether their CO2 is out of control and things like that. Are you causing more harm by that strategy than going for ECMO? So they definitely something to consider trauma. Again, the fears are just causing, you know, large hemorrhages and stuff in this creep, but it's probably not true. And actually, ECMO probably is helpful and we've certainly taken some particularly chest trauma um and had reasonable success. We've done rib fixation and stuff now on ECMO with people with chest trauma. So again, I think there are people group that we actually are more likely to consider. And the previous historical thought of bleeding is probably not an issue. If anything, it's actually a hypercoagulable state. That's an issue that you have to manage with your circuit interstitial lung disease. Yes, if they got fibrotic changes, clearly they're not probably going to be a candidate if they're in the early phase. Um, and you want to get immunosuppression and things during it then, yes, they're a group. And again, we haven't done many of those people. We have done some kind of weird and wonderful ids and allowed immunosuppression to take place with, you know, reasonable uh success in that group of people because essentially, once you get the immunosuppressed, they could potentially get back to a reasonable, good quality of life. Um HIV again, was a almost an absolute no to ECMO going back. But now we've realized actually these patients, um if you support them through their, I guess P JP often uh component, you can get immunosuppression, you know, so you can get um antivirals on board. Um eventually and you can kind of get these people back and we've done a few. Um we one did very well, one unfortunately had a complication from of ECMO and she brought hemorrhage and stuff, but actually got better from a chest point of view. So it is, it does work. Um sometimes they end a bit longer runs and things. Um But generally, uh that group of patients actually do pretty well and they've actually got, you know, actually these h I people have a decent life expectancy. So, um, definitely worth considering them. There's certain things that, you know, within the kind of CT scan and stuff that might make you nervous about it. In terms of we do, there's a bit of discussion about, you know, if they got quite significant damage to their lungs, they may just not, um, repair, you know, recoverable, but essentially So if they get a CT scan before that can be quite useful. But often these people, you just can't get that and you find that out once they're on. So again, it's not an absolute kind of no to that group of people, if anything, they're a good group of people to put on. So now we're just kind of flying on to kind of the final kind of like bits about service and stuff and a couple of quick cases to finish with. So the network is configured um with a number of centers around the UK. So there are essentially now essentially six in England, Bristol have now taking on an area of England. Um and you've got guys Brompton, which are now the same trust. Interestingly enough. And Pat Worth er, Leicester and Manchester and us as the Scottish Center. So all the centers are commissioned to provide ECMO, but also to do Mobile ECMO, which we have to be able to provide to go and retrieve the patients, which is actually quite different to the pediatric side of things where you can be an ECMO Center without the ability to retrieve. So this is our set up that we've kind of developed and things. So we have a big black box that contains all our cannulas and everything we basically need. And we've added a few additional things. So we now carry nitric oxide on our circuit, we changed to Hamilton. So just those sort of patients you think you might get back conventionally gives you a little bit of safety margin to come back with. Um So we do bring some people back conventionally who don't maybe need um ECMO. But essentially, we take everything that we can need with us on our retrieval, we also take additional stuff so that if you have a, something goes wrong with the circuit, you can manage that while you're out and about. So you can replace an oxygenator or something, which we've done um a few times on transfers. If there's a issue, we ate, it fails en route, they need to be able to deal with that. So cut it out and place replace it. So the team is kind of trained to do those sort of things. The other element of the ECMO is actually when they're managed with us and it's like physiotherapy on ECMO. So all these patients are kind of given them permission for their patients faces to be shown. So, you know, we have them on the tilt table, have them on the bike, sometimes the, you know, feet, arm bike, you know, standing and we try and get them standing and things. So we don't manage all our patients awake. That's an absolute life. You say that and in essential, who tells you that? It's also not true. Um, but we do try and wake up, particularly the longer runs and try and get them awake, but often in the acute phase is actually quite difficult to wake people up. Um And you tend to want to get a bit better. So that's often why lung transplant patients are far easier to manage awake on ECMO than your acutely respiratory failure type patients, they behave a bit differently. So, but we do try and get our patients awake if possible and um participating in kind of rehab at that stage. So, since Scottish commissioning, um this is our data. So I've taken a bit longer for it to get to this stage. So um this is basically bench marks you also. So um the first two years in COVID, our, our survival um this was basically to de cannulation. Um It was lower than I guess our previous um data was. So in the last year, it sort of jumped back up to a pretty high um survival to de cannulation. So that's one thing we look at doesn't really tell you anything about your service. I don't really know. Um because basically, you select the patients to put on. So you can kind of manipulate this if I'm brutally honest. Um So I think other things you need to look at is kind of six month survival. So we look at the patients that we accept and obviously that looks a bit lower than the previous slide that I showed you. And that's partly because at six months last year, we had two patients that died after um they went back to their other hospital. And then I look at those quite closely to see whether or not, you know, should we have offered ECMO to them? Was there something that, you know, happened? Um, and essentially definitely one of those had their underlying disease process recurred and I don't think there's anything really to change and even the other one had a severe pancreatitis and things and I, I would still offer hemo to that person in that thing in that condition. Obviously accept that there is a possibility they may not make six months. And then we take some people, um, conventionally, these are the groups I think kind of more interesting and kind of want to keep an eye on. Really is some man referring hospital. We think they're a candidate. We kind of want this group here to have good survival. And certainly last year, the ones we thought we just managed conventionally did actually pretty well. Um, not a candidate actually last year, they also did pretty well. In terms of, um, outcomes, even people we think aren't not eo candidates for whatever reason, they might still get better conventionally. I think that's the important thing to remember. Um, is that is not just, er, we're saying they're not going to get better. We're saying maybe Echo is going to survive, provide no survival benefit. And really, I mean, interestingly did it just, so you take it, you still, at least with that. So I thought you disappeared or something and I just actually hit the screen, had a moment of panic that all that disappeared. Um So let's go back to that slide. Um Even the ones that we thought were gonna die actually last year did quite well. So I always ask the question, how many echo patients can you have simultaneously and what limits this equipment based based staffing levels? I'll do one more slide answer to that question um because it'll fit nicely. So since commissioning, we've done 480 odd referrals, we accepted between somewhere about 15 and 20%. It was lower probably. And COVID is now kind of drifting up to last year's act. Well, this year's been, we've taken almost 50% which was quite early on of referrals, but last year kind of about 20 odd percent. Um We think about 40% of our candidates looking back would be deemed candidates at the time of referral. We've done just under 80 cases that the number of bed days. Interestingly enough, we had, our bed day per run was high during COVID over like 20 days in the last like year, it actually dropped way down. We've had much, much shorter runs, um, probably just due to the kind of disease process and more, um, post ECMO bed days, um, have dropped again and everyone was really good at getting people back. And I'm honest, like we very rarely have problems with getting patients back and we tend to keep them a bit to make certain and they're really good before we go back. But generally, as soon as we phone up centers, they're excellent at getting the back. So that's much appreciated the question about what's a limiting factor. Um In COVID, we did up to, we had six on at one point. Um So in terms of equipment, we've got enough to do it, nursing staff, we've probably got enough if you just did ECMO, it's when you add in all the other stuff we're commissioned for two at any one time, basically. So the issue is that's actually quite a knife edge and quite often you can be, you know, one patient and get a couple of referrals and suddenly have two on. Um, we tend to flex above that. Um But it just in terms of balancing that with the rest of the hospital and how that works with everything in terms of how we're commissioned. So the limiting factor is probably what we're commissioned for, um, and also I suppose the criteria that we're working to, um, from the UK network. So I suppose you could take different patient groups and maybe we are overly cautious. I don't know, we try and believe in ability across the network. Um, but I accept there's variation between practice and we probably use more second opinions than other centers because being a smaller center and relatively new into the referral part of it, we do ask other centers about whether they would put them on. Um Generally, we have agreement, maybe not always. But um and we have on one time, maybe put someone on that, someone else said they might not put on and they did actually survive. But I don't know how much you can really read always into these things. So just to be about governance process for the kind of couple of cases before I finish as nearly after eight o'clock. So we do have a reasonably strong governance process internally. We look at like delays to um phone back, delays to leaving. We look at all our deaths um on ECMO. Um and then we do, it's quite a bit more difficult to nail down into the death and the group that um we don't take, but it is quite useful to find out. And we see e may just phone up to find out how patients got on and it is sometimes useful to find out why did that? Patient die. Was it due to hypoxia? Um because they're the case that are sometimes quite worth looking into and that's sometimes a little bit harder for us to always find out. So that group that we say are a candidate and then they die are a group that I am quite interested in because I feel that why did that person die would have ECMO saved them. So I guess if you have patients that we say are a candidate and then die, it is quite used to get some information about what happened. Um And that's not because we think you guys would be saying you should have taken them whatever else. It's actually because that would aid learning. So maybe that's something we could we should look at is how we get that information and maybe the other referrals as well because maybe we should have done something different with those. Um So they're the groups I think are probably more interesting rather than your ECMO group. Does that make sense? Just quickly, I've got two cases just to quickly demonstrate, I guess a bit of stuff that we've done over the kind of last year and I saw these cases are picked because they basically gave permission. So that made it easier. Um So I need to find some other people to give permission for cases. Um And possibly also referrals are interesting to look at them. We maybe don't take again, I just was a bit cautious about putting them in to this. I know is getting recorded as such. So the first case, 40 year old Staph caffe pneumonia, Broncho fis essentially had refractory hypoxia got retrieved on day six of their illness, had a very long run and it was complicated by essentially airway bleeding and then trying to manage that circuit versus bleeding problem because we don't run anticoagulation. Your circuit is probably more likely then to cause problems with coagulopathy and bleeding against trying to stop the actual active bleeding. So that kind of dampened our ability to do anything for quite a few weeks, essentially while we tried to let the bleeding settle. And then we had this debate about how should you deal with the, um, underlying pathology like your surgery. We've done a few people with, um, cavitation pneumonia before and some, we've done thoracic surgery on which was quite difficult to manage at the time because it caused lots and lots of bleeding issues and things. Other ones we managed conservatively, just hope they got better and they did. Ok. So this guy, we kind of went through a strategy of, um, initially trying to rest the broncho or fistula. So we did put a double lumen tube down, but it was actually really difficult to manage, um, and even toilet his essentially good lung. So we attempted to wake him up and extubated him. So we had an extubated for a period of time on ECMO and he was ok, he had a really poor ability to cough and just really kind of silt it up. So then we elected to put a tray in, then wake him up again and keep him awake. And we just never really got the broncho fistula to heal even when he bled into his lungs, which is kind of like a sort of internal blood patch that didn't even work. And then we had lots of debate about whether in the bronchial approach would be right and when you should put it in, so this does demonstrate cross, I guess, um, working that had, um I thought it was maybe a good idea. When should I put it in? And what's the infection risk and things people to really find out, spoke to Tommy, who've actually done a few, the only other centers done many on echo about putting in bronchial valve. So they felt they would probably wait sort of quite a few weeks before attempting it and then had an opportunity when there was appeared to be low infection point to try and place. And then, um, so that's what we did. I'll just show you a couple of, got a little work, but this is basically what his um CT looked like on admission to ourselves. So you can see he's got a significant left sided kind of disease with um a big mo pneumothorax. Um But also he's got significant disease in his right lung. At this stage. And that's why he was very difficult to manage conventionally. So as soon as you apply positive pressure, it just came out of this big hole, which was like 5.5 liter leak. Um So we placed some endobronchial valve. So just here to show you what that is essentially, this is his x-ray at one point just completely collapse in blood. Eventually he managed to clear out. So he blew a balloon up into his, we thought on CT from thoracic radiology was in his left upper, inflated a balloon to try and work out where it was coming from. He took out his left upper completely initially, which got us a bit better and then ultimately had to go back and actually take out his lingula due to some additional kind of feeder into that area. So, um he then actually very quickly once we had blocked it up, um came off ECMO. Um and this was x-ray. Um And he got home, I think eventually he almost back at work. So a case, a case that should be have intervened earlier with endobronchial valves, possibly. Um But showed that I guess we could support him while we kind of worked out how to fix it. Um In a young person, I think it's been an older person, you probably wouldn't have had the success and he was very motivated and while he was awake, he was doing rehab and stuff on ECMO. The other one, just a, a slightly different older person who had airway obstruction and pneumonia and presented in a way that appeared just to have like a pneumonic process, didn't have any symptoms or kind of an airway issue. But once got intubated was very difficult to ventilate. And the bronchoscope showed that he had what appeared to be a tumor in his, like, er, trachea or maybe coming from his, um, bronchus. Um, so we picked him up, put him on ECMO. Um, and then my fa and debulked it and it was, and the radiology, it looked like he had a CT prior to ECMO looked like it was a lipoma. So he quite competent that this is probably something that can be reversible. Um, and then debulked and then he actually got off, ECMO, basically recovered from his infection once he'd been debulked and then went for a kind of definitive bronchio and has been discharged home. So that kind of shows his xrays. Um, and then basically this is this kind of large kind of lipoma sitting in his, um, sort of bronchus and trachea. And he looked back at his history, he'd been diagnosed with possible COPD. But actually, I think he just had this and it was a very classical actual history of someone with a lipoma, but they represent sort of like less than I think 1% or about 0.2% or something of all endobronchial tumors. So, we'd already taken a bit out, but this is what it was, it was sort of deking and then this was his kind of x-ray. Um, after that and that's it, sorry for overrun. It slightly got a bit carried away. Great. Thank you so much, Ian. That was a fantastic talk and we probably do have a time for a couple of questions. Uh If you want to ask a question, just type it in the chat box. Um If you don't mind, I do you mind if I ask a question to start with? So I sometimes as a non, as a non specialist, I struggle a little bit with knowing when exactly the right time is to refer. So you've got someone with severe sy failure. Do you want to know about them at the time that you're initially pruning them? Do you want to know about when you've got pruning failure? Uh What's the right time frame? I'm conscious of not referring too early and then also not leaving it. So resource can't be mobilized effectively. Yeah, I think it's a, it's a really difficult question to um fully answer. I think, I suppose it depends a bit about the stability of the patient and I think we're gonna probably suggest pron um And I think I'd be comfortable that people, you know, start the prone episode. I think if you prone them and they suddenly start weaning really quickly, then that's fine. If like, you know, an hour or 23 hours into it. You're not really seeing a pro then that I guess, and they're otherwise stable. Yes. Refer at that point we're probably gonna say extend that pron episode. Let's see what happens in six and maybe at the end of their episode, um, before maybe coming to go and get them and it may be that they have a response. So they're gonna say, put them back super high. And the, the difficulty is that people are responding to pron at least I think where, when, when do you then decide to go and get them? And I think the general feeling is that if pro is working, you should continue with that, even if it's multiple episodes, I mean, Reba study suggested, you know, I think that means something like four or something, but potentially could have many more than that. I think they're responding. Um You would carry on doing that. So I think they, I think starting the pro or if there's something in the history or something that is, would they be a candidate? It's more a question of, is this person a candidate rather than doing the echo right now? That's also beneficial to have that earlier conversation, especially they're complex because maybe we don't know the answer to it upfront on this. A lot of stuff is difficult to actually answer. So we're gonna need some time to suss it out. So there's different things we can do we can obviously ask other people, you can look at the registry and you can try and pull up some data to try and get some cases and stuff and speak in the center that takes time. The referral plat refer patient platform. Well, it is probably a pain in some ways is amazing for us because it allows multiple people to look at referral very rapidly and we can send that to other centers who can then look at it. So it's why it's used across the whole of the UK. Um And most people like it. I do accept this in terms of the questions. We've probably got quite a lot of questions in it. You don't have to put all the data in, you can get away with not putting it all in. Um but it's very useful for us for internally, not just a consultant on call is looking at it, but so much that other people are and you can like get information from them. So they're probably the two things I'd happy to start pron and start the process. If they're not looking at it, responding then or if you know, maybe if like they compare the first episode, maybe the second one's not quite as good. Then again, they're ones maybe to know about because we might try and plan like, you know, pro episodes so we could mobilize at sensible time and things. Um Hope that kind of answers. Yeah, that's helpful. Uh, there's, uh, I was asking about, uh, APR V in sort of trials of Apr V prior to ECMO, given that there's not much evidence base. Um, how do I answer this? I don't really know the answer. Um, I think there are patient groups. APR V. I was probably, maybe not a mass. I didn't really know where APR V set in my, like, where should I use it where I shouldn't use it? I kind of decided I kind of trying to use it a bit more just to kind of get a feel for it. And I think there are patient groups that do better with it, you know, obese patients and stuff. I think you can, that open lung strategy does work. And there's a, a couple of patients we've taken recently, like put on Apr V once we brought them here because I felt it was more kind of collapse rather than anything else and went for that strategy. Now, whether they've gone on to it beforehand, would they avoided ECMO? I don't know or was it the fact that they're on ECMO, you could kind of re expand them and it didn't actually matter. Their oxidation might have got worse because I, sometimes when I put them on it, I found that if they just got their, their collapse lower, actually, when you go on, they actually desaturate because essentially just cause it basically shunt effect where basically just obliterating their blood supply to a bit of London did have some ventilation. So it's difficult to know. So I don't know where it truly sits. There are, there is a plan for an Apr V study. I know that's about to be done from, I thinking Lui has won the bid for it because one of my colleagues is also trying to do an APR V study and they had a, um you know, came down to that one getting picked. So I think some more research will be used in Apr V where it sits and even on ECMO and things like that. So I think it is useful if you, if you've got experience with it, then maybe trying it is that balance between, do you risk it and make things worse or do you kind of go for them? So, um so yeah, there's another question about E CPR. So essentially the, the short answer is no, the longer answer is that we will offer it for certain things, um particularly hyperthermia. So we have put on predominantly hypothermic patients. We kind of did do a few other cases and had some not great outcomes from it. So, so we do kind of consider in house kind of hyperthermia. We take even elsewhere in Scotland for kind of hypothermia and consider them. Um But it's probably that very specific group that we're going to take for E CPR, I don't think it's kind of difficult to know where it sits at the moment. Um I, I do have another question. It's more a personal opinion question and, and so there's obviously some evidence that patients who have severe respiratory failure do better in high volume centers and like other conditions that we manage in, you know, specialist area, you know, in specialist centers. Do you think there's an argument that all patients, there's an argument that all patients with severe respiratory failure should be transferred to somewhere like your units? Um Or do you think this is something that local units should maintain? Kind of uh you know, I a control of essentially um it's probably difficult to be certain of the actual answer and partly because, you know, the risk of transfer is that inherently going to cause harm that you could have avoid, you know, and I guess the question is, do we know are we bad at it at the moment? Like what, how there is some evidence? But where's the evidence come from? Like, do we know as a Scottish network? How good are we at managing Spirit Care payments? And I don't know if we truly know that data effectively and maybe that's something as a network we should or as a Scottish wide intensive care society should look at how can we be certain and we're providing high quality respiratory care um in every center and maybe we are and maybe we don't need to or I mean, I think if you went down that model, it'd be a kind of like in terms of logistics, you know, and where would you cut it off? You know, what would be your severe respiratory failure? Would it be somewhere with a PF ratio of 20 where they all go or not? So, I kind of think that um but probably, probably actually not bad at it as in Scotland, but I think it would be useful to know if that's true and then whether or not would moving them helpful or would it be actually just disseminating, um you know, you know, hub and spoke type thing, maybe these people would get referred earlier and it would be advice that may be ok, maybe you should give steroids in this person because I mean, that's a bit of a hot topic. But, you know, is it steroids you should give, is it like a ventilatory strategy such as Apr V or something? And having that may be useful? Um But I don't really know the answer whether we should, I don't think it would, the funding or how it would work would be the biggest stumbling block to something like that actually ever happening. Perfect. Thank you so much. I can't see any other questions um coming through on the chat there. Um So thank you so much uh to use Sco was a very, very interesting talk and uh and you're a very good speaker. So thanks so much for giving up your time. On this Thursday evening to come along. So that ok, um uh there's a link to feedback in the chat there. Um And uh, you, you, the Scottish intensive care society is a evening education updates are taking a summer holiday. Um So we were there will not be a, a session in July or August, but we will be back in September with further kind of widespread talks from subject matter experts from across the Scottish intensive care of network. So, thank you so much for all of you that have joined. It was lovely to see you all and, and hopefully catch up with you soon. Enjoy your summer. Thanks so much. Bye then.