All righty. So yeah, so moving on to the, the diagnostic evaluation of these patients a little bit more. So, We've talked already about how we, what we do initially and what we can get from this sort of more targeted physical exam, which is all well and good, but, that might give us a lot of information, but it's nice to know that there's other things out there that can help with patients that really aren't as clear cut as they we might want them to be, or patients that we just want some extra confidence from, frankly, before we start sticking needles in them and, and various other things.

So, We'll talk about the use of diagnostics that might be appropriate in these cases. And then I really wanted to spend some time at the end of this second talk thinking about how can we really tell if respiratory distress is cardiac, because that's basically one of the, the big questions that we've got. So what do we have at our, at our disposal to be able to sort of figure that out?

And so as you said previously, it can really feel like we're stuck between a rock and a hard place and that we need to get these patients more stable, but, we can't really do a whole lot with them to be able to figure out what it is. And we're meeting them at a point that they're at their worst and at a point where they're sort of definitely behind in the sort of balance between, option delivery and consumption. So we need to bear in mind that whatever we do, we can't sort of mess up that sort of fragile balance that they've got going.

And the problem comes with what do we do next, so what treatments needed, what do we think they've got, and therefore what treatments needed. And I mean, there, there are literally textbooks written on this, and this is one of my favourite textbooks and respiratory diseases. I've learned a lot from this book over the years.

But it could be anything. There's, you know, 1,000+ pages in this book. And so, what do we kind of do next that's the right thing for the patient that's, that's using veterinary medicine appropriately that isn't just treating everything in every patient, that might be sort of missing something important in some of the others.

So what do we actually do? And in any other situation, we would be employing diagnostic tests at this point in time. Like you wouldn't be doing a medical workup based on best guess.

You'd be sort of doing sensible diagnostics to try and sort of figure out what the actual problem was. And there's lots of things that we can do frustratingly to investigate patients with a sort of respiratory disease. So, you know, chest X-rays, echo, we can, you know, check airway samples, we can test the kind of other things that we think might be going on, but In these patients, it's often the case that the, the patient will not let us do that.

And so it really is if we're thinking about what diagnostic tests are needed, it's very much in the context of what's the risk-benefit ratio. And I put in here, this is a radiograph that, I have to say I don't know where this radiograph originally came from, but this shows probably one of the worst cases of pneumothorax I've ever seen. So, It's not some kind of contrast issue with this image and as I sort of highlighting here, this is the remaining lung tissue and that's been completely compressed with all of this extensive air here.

And yes, this image was diagnostic, but I suspect this came at a great cost to the patient, and hopefully we could have found out what the, the problem was without necessarily resorting to a, a radiograph that could have well made this patient worse. So, It's thinking about what, you know, what is the best thing to do for the patient at that point in time. And so again, back to this sort of anatomic approach, can we use this in the context of sort of our diagnostic findings to try and, and then figure out what the, the most likely thing is.

So if we can narrow down the category we think the problems arising from, in my mind, that's a great thing because I've cut down on a tonne of other differential diagnoses. I've, you know, I've effectively lost 800 pages of a textbook, which is always a good thing. And I can concentrate on what's, what's most likely and prioritise sort of things that I can do to try and stabilise the patient a bit more.

And we saw this, this, slide in the, the last presentation again we're sort of looking at each of these localizations and saying, well, what, what does the typical patient do? And we talked about clinical signs that they'll do. But what I wanted to do in this talk is to take each of these in turn, talk about the breathing patterns and, and talk about specific stabilising and, and treatment, treatment options that that come up as well.

So if you kind of start from the beginning with the, the upper airway disease, a really notable feature of, of this sort of problem is that upper airways tend to collapse when a patient breathes in. And that happens ordinarily, but if, if they're not diseased, if they're not sort of exerting themselves, then that's not really a problem that we pick up. But if you have disease in that area and there's non tenancy, then you end up with a big problem.

The best way I can think to describe it is if you have, significant upper airway disease, it's like trying to breathe through a straw. So, If you're asked to sit there right now and do that, you'd probably choose to breathe quite slowly and deeply, and you'd, you'd be able to handle that. But if I ask you to go do some, some sprints up and down the street, then that's not going to go so well.

You're going to try and breathe in harder to try and get more oxygen in, which is going to collapse your straw, AKA your airway a bit more, which is going to make you panic, which is gonna make you breathe harder. And so they end up in this very sort of vicious cycle where they spend a long time breathing in because that's the 10, that's the part that their respiratory system is, is limited by. They can breathe out just fine.

It's breathing in that's the problem, and they get much worse by stress because as we said, this sort of sets up this whole cycle. They might also have some inspiratory noise as well that we hear with our, our stethoscope. These, I mean, these are the dogs that we sometimes hear coming.

You can hear them sort of arrive in the waiting room and, you know, they're, they're not really a medical mystery when they, they come in. But we may just appreciate sort of upper airway noise and auscultation. There's a sort of more subtle but equally localising factor to say it's an upper airway problem.

And there's lots of things within this category it can be. So once you've localised the patient saying you've got upper airway disease, there's still a whole host of differential diagnoses that sort of listed at the bottom of the slide here. But they all have common ground and similar things that we can use to stabilise the patient regardless of which exact thing this this patient has.

So that's quite a, a useful finding. And There's less scientific ways of then going ahead to distinguish between them once the patient's stable. My favourite description I've ever had of this is somebody said about the one hand versus two-hand diagnosis.

So if you can pick up a patient with upper airway disease with one hand, it's probably got tracheal collapse. If it takes two, then it's probably got laryngeal paralysis based on kind of the size of the patient. So, not an exact science, clearly not for every patient, but, but you can then hopefully get them to a point you can work out which one of these things it is.

But in terms of stabilising upper airway disease, again, oxygen kind of goes without saying, but the minimising stress is, is super important in these patients. So be that in terms of being mindful of their handling, but sedation, as, as soon as we have all the consent, basically, after that sort of initial survey. With a drug of your choosing, I've listed some of my favourites here.

And whether you use, one or two, as your sort of starting point is going to depend on your clinical judgement as to how bad things are. And you may well, you know, escalate things if something's not really working, you may decide that something else may work a little bit better. It's about striking a balance as well with this because I know I've given, I've given one thing and it's not really worked, so I've given another thing and that hasn't really worked, and I've given a third thing, and then they're completely flat.

So I think it is a balance, but if they are in true respiratory distress from an upper airway crisis, then sedation is, is important. So some kind of suggested doses here, but obviously tailored to effect for your individual patient. And these are all drugs that can be given intramuscular, so we're really not stressing out these patients to place IV catheters unless we think that, A, we've got somebody who's a great shot at getting one in, and B, more importantly, that the patient will tolerate that reasonably well.

The other thing that's caught me out with these patients before is because normal upper airway functions really important for temperature regulation. These patients can get hot. It, it, it almost instantaneously.

It's really quite incredible. And so checking temperature again, as you said, not necessarily something that we often do with our regular emergency patients unless we suspect that there's a big problem. But I've seen these patients go from 0 to sort of off, off scale high, very terrifyingly quickly.

And of course, if we're hot, then that's going to set off a respiratory lookalike, as we mentioned in the last talk, which is going to make them breathe harder, which is going to make this whole situation, 10 times worse. So active cooling if their temperatures rising, because unfortunately there are cases that I can recall that have had a heat injury and sort of heat stroke like syndromes after an upper airway crisis, which is the, the last thing you sort of want to add on to them. But again, regardless of the specific cause of the upper airway disease, if this isn't working, then we can always go to intubation.

And as a last case resort, if there's no other airway access possible, then I refer you back to the things that we talked about in the previous talk that may include tracheal oxygen or potentially even a temporary tracheostomy, as well. Lower air airway disease, basically the counter of what we've just been saying. So the lower airways are the ones that tend to collapse on expiration.

So, typically these patients with lower airway disease will spend a long time breathing out. So, you may well kind of recall cats you've seen that had like a really big exploratory push to their breathing, and that's probably a sort of lower airway disease type breathing. They can breathe in just fine.

It's the breathing out that's the issue. Sometimes it can look a little mixed, but they'll, they'll be generally be a component of exploratory effort mix in there as well. When we have got these patients, they'll often have, have wheezes kind of representing the fact we've got air moving turbulently through these sort of small airways and within the lungs, sometimes some fine crackles, but they tend to be fine at their worst.

And again, maybe accompanied by a cough, so previously you said this was, if, if I had a coughing cat, I thought it either had asthma or if I was still in the states, it might have had heartworm. And now, you know, that doesn't necessarily, as you said, rule out things like cardiogenic and causes of respiratory distress, but coughing can be a notable feature of lower airway disease. And the good news about this particular anatomic location is that dogs, once they get chronic bronchitis and so on, it's, that's not really something we see as an acute presentation.

They, you know, they cough, they come in for sort of a, a, a routine appointment. They don't tend to be in respiratory distress. Whereas cats really their only equivalent of this is, and asthma, this allergic airway disease, whatever we want to call it.

And so if I see this in a cap, that's basically my diagnosis right from the start, and that's what I'm, I'm working towards getting them stable. And so it's a really nice way of basically shortcutting through all of the other things it could possibly be. And then in terms of specific stabilisation, then thinking about is this a stressy cat?

Would some sedation be helpful? But thinking about, well, we know it's a condition that's associated with inflammation with bronchoconstriction, and so I'm basically gonna treat for both of those, with drugs that are generally pretty widely available. I'm probably, maybe showing my age.

I'm still a little old school, but I'm, I tend to go with IM versions of intramuscular injections of these drugs, so I know that they're in, they're done, they're quickly in. I can, you know, start, start the clock ticking as to how long they should respond. But also long term, we know that these patients can do really, really well and inhale therapies, and I know people that use this in the acute setting, and if the patient tolerates it well, I think that's a great idea.

But it's probably not, my concern is that if it stresses the patient out, I've lost a little bit of ground. Again, it's sort of clinical judgement as to how best to get these sorts of drugs in the patient, but that's the sort of basic principle behind it. So the pulmonaryar cream itself, I'm, this is a bit more of a head scratching kind of moment because when I'm looking at them breathe, it's, it's a less specific than, than we've said for the sort of distinctly upper or distinctly lower airway type breathing.

So it's often mixed, it may sort of be rapid and shallow. It's just, it's just not that suggestive necessary. They just tend to look this, for want of sort of a, a better, description.

In these patients, it's the auscultation that's a bit more specific. So this is where we listen to those lung sounds and they're harsh. They're just louder than they should be for a patient of that particular size, for that particular effort.

So it's just more than there should be. Crackles are a lot more specific, and we can start thinking about, the distribution of those things as we'll talk about the history of the patient to sort of figure out what the most likely causes. So this is very much sort of putting together pieces of the puzzle.

And quite a few different differential diagnoses for this anatomic location, of which this isn't an exclusive list by any means, but just some of the more common things that we tend to see. And for example, if we take something like an aspiration pneumonia, maybe it's a patient, history of vomiting, develop respiratory distress, as common things are common, we're thinking, could this be aspiration pneumonia? If I hear harsh lung sounds or crackles that are most prevalent in the cranio ventral or right middle lung lobes, when I'm a skulting, then for me, that's, that's pretty much I'm 99% of the way there.

Similarly with these other things, some of them are fairly specific, some can be quite variable, so we're not necessarily a whole lot further on if it's maybe pulmonary haemorrhage or contusions. Or neoplasia, but some of them, again, I'll take any clue I can get when sort of dealing with these patients. So it's again, finding out the sort of subtle, subtle signs and putting together the pieces of the puzzle.

And potentially in auscultation, we can distinguish between these two patients. So up here, we've got nice cray ventral harsh lung sounds. I'm sure there'll be crackles on this patient with a, a beautiful aspiration pneumonia.

I say beautiful radiographically, probably not for the patient. And down here, much more of a cor a dorsal distribution of the alveolar disease of, of a patient who's been, chewing on electric wires when they shouldn't have been. In terms of stabilising pulmonary fraal disease in general, one of the most important things, just sort of general approach to these sorts of patients, is to think about positioning.

And whilst that's true in patients with any sort of respiratory distress, having patients with lung disease and sternal recumbency makes a huge difference to their oxygen levels. There was a nice study a few years ago that sort of actually documented this, numerically, and it made a big, big difference. And I think clinically it's something we appreciate as well.

You can have a patient who looks terrible, and you put them in sternal, they look like a different dog almost. So kind of bearing in mind the simple stuff, even though we might be sort of a bit worried about everything, not forgetting the, the easy stuff that can make a big difference. And then I'm back to sort of my treat the treatable tirade again.

And I, I think, whereas, you know, the, the old saying is nothing should die without the benefit of steroids. I really believe that no patient with respiratory distres should die without at least trying some frozenides. It's cheap, it's cheerful, worst case scenario, it doesn't work.

And so if I have a patient, if you, I even have a suspicion that there could be a component of cardiac disease related to the respiratory distress, or it's a patient, for example, who's maybe been in the hospital on fluids, who's developed some respiratory distress that I think could it be related to its volume status, any suspicion, I think something want some frozamide. And again, if it works, you tend to see a response within 20 minutes or so. So you don't have to wait forever to see if it's working.

We can give it IM and generally speaking, it's quite a sort of satisfying experience if they, they are gonna respond. I'd say most patients I've seen respond really well to this sort of low dose bolus kind of repeated to effect. I tend to be more of a fan of low doses given more often than a sort of giant dose kind of upfront, and I'm aware the formula has sort of quite a dose range, I believe up to sort of 8 milligrammes per kilo, something like that.

I'd rather give that in sort of 4 to 8 smaller doses rather than sort of one big one just to have sort of more sustained diuresis over time. And some patients actually Won't respond great to intermittent bolus, but just become like different patients transformed if they're put on a constant rate infusion of frozamide. So I put the dose range here, and I tend to start at the lower end of the dose of 0.1 me gig per hour, usually make up the, the infusion to run that at 1 mL an hour because I don't want to give them too much volume with their CRI and potentially make things worse.

And then just sort of see, see how they go. You can go up, go up on that sort of gradually and just to sort of get the desired effect. But frozenide, if you even, even have a thought that could this be cardiac and, you know, we're struggling to get through what it might be, some frozenide is the way forward.

Well, the stabilising treatments aren't really gonna work as quickly. So if we suspect that there's a, you know, an infectious focus, there's an aspiration or a kennel cough pneumonia, then antibiotics absolutely should be started, but like any sort of other treatment of infection, it's going to take time for them, so we shouldn't really expect, a, a rapid resolution of clinical signs, unlike we might see with rosemide. And again, if there's anything else that's going on, then they're sort of treating that concurrently as well.

The other location, the plural space, the breathing patterns that we see there is, as you sort of alluded to, we've always sort of rapid shallow breathing as being sort of plural space, but, you know, the average cat with respiratory distress will, will often have sort of rapid shallow breathing, so I'm not necessarily as specific as it has been, but it's so dull lung sounds that are the, the really big clue. And sometimes with really bad diaphragmatic hernias, you might hear gut sounds in the wrong place, which is, is always interesting. But it's, it's usually the auscultation that's sort of like a, a key player and Again, probably not an exclusive list of differential diagnoses for plural space disease, but, lots of things that it could be, whether it be air or different types of fluid, or potentially organs as we've just mentioned.

And we'll talk about this more in the, the next talk today as well. But in terms of stabilising plural space disease, they get oxygen. But again, if there's even a suspicion it's plural space disease, they should have a thoracentesis done really quite promptly.

As in, you know, you have the stuff together, you get ready, you go. And the reason for that is that it, if you have a floor space issue, then that's really the only thing that's gonna sort it out. And no other medical management is going to cause that fluid to kind of be, be removed anytime soon.

So it's really the only thing that we can do to help them. But it's also immediately diagnostic, which for somebody like me dealing with emergency patients and quite impatient by nature, it's, it's really nice to be able to kind of get immediate response to say, yes, that was the right thing to do. This is what this patient's got.

So it helps with, with both of those things. And of course, then we can collect samples that we can sort of send off later as well. So again, any suspicion, thoracocentesis is indicated and As we'll talk about in the next session in terms of complications and so on, you don't really have a whole lot to lose by by trying this as well.

So I'd encourage you to, to move on with that promptly if you're suspicious. Obviously, that isn't really gonna help if you've got a dramatic hernia, but if you've got one of those that's just not really stabilising and, you know, you're potentially thinking about going to surgery on them, but you're not really thrilled about anaesthetizing them, thinking about body positioning again and even something as simple as, Lifting up the animals so they're, they're stood more vertically. So, you know, standing more like, like we or I would, you or I would.

Sometimes that and a little bit of a jiggle, for want of a better word, can help those abdominal organs relocate back into the abdomen again, and freeing up some space for the lungs. So it doesn't work with all of them. Again, we don't want to stress them out too much by sort of jiggling them around, but sometimes that can make a big difference to how stable they are as well.

And I kind of, I, I think what I've probably presented here is the fact that If you can be sure as to which location is affected, you can be pretty confident that you can do something to stabilise them that should work pretty quickly. The problem is if you have lots of locations affected simultaneously, it can make it a little bit more muddy. And I remember this was a case I saw as a resident that was a massive trauma case that came in, horrible respiratory distress, and I'm looking at this dog breathe and it just looked dissic, and I cult the dog and it sounds normal, completely normal, and you know, my senior asked me how does it sound and I say it sounds normal and everybody's looking as surprised as me at this point.

And what actually happened with this case was, as we can see that there's, there's definite rib fractures over here, probably not helping things. But there's quite a significant pneumothorax is sort of shown by the cursor over here, which by default, as we said, should make our lungs sound quite dull. But just underneath that, we've got some raging pulmonary contusions, which should make our lungs sound quite harsh to crackles, as we've mentioned for lung disease.

Put together, they averaged each other out and we had perfectly normal sounding lungs, but there was a disconnect because the patient was so, so disconnected, so we knew that there was, there was definitely something. It was just a case of finding out what it was. So.

Being confident about how these patients breathe with, with just one problem can make sort of solving that problem a little bit easier when there's sort of multiple locations affected as well. And this is probably one of the most common examples of that. So, this sort of the physical exam we talked about, these sorts of auscultation findings, etc.

That we've just talked about is, is often enough to figure out what the most likely thing that is going on is. But there's a sort of a new technique that's, to be honest, is really becoming valuable as to how I approach these sorts of patients is the use of patient side ultrasound. And this is something I want to spend a little bit of time going over.

It may well be that a lot of you are sort of using this already, but it's something that's evolving quite rapidly in terms of things that we can actually tell from this. And so I thought it might be worth mentioning in a bit more detail as to how we can apply this to these respiratory distress patients today. And I should say that this is patient side ultrasound where the ultrasound is brought to the patient.

So this isn't getting them sort of wheeled off to where we normally do the scans and getting them all clipped and prepped and positioning them in, in a certain way. This is basically a simple portable machine being brought patients side, they're not being moved and positioned. It's having the patient being positioned however they want, they can be sternal, they can be lateral, they can be standing.

We'll sort of work around them. We're not clipping the fur, and we're just sort of gently, gently passing it and you know, using gel to kind of look in certain windows, but again, not stressing them out to kind of get them all, all ready for sort of like an official ultrasound, if you like. So lots of benefits in terms of your minimising movement and handling of these patients.

And has lots of terminology, but it's kind of the original term that I this was sort of introduced in veterinary medicine, that was used was, was so-called TFAST, which stands for thoracicocused assessment with sonography for trauma. And its origins like in human medicine, so in, in people, they'll be doing this to look for trauma injuries. So in the abdomen there's AFAST and thorax is a TFAST.

But it's actually evolved and now we realise that it's actually a lot of utility, not just in the trauma patient, but in triaging any sort of emergency patients, including those in respiratory distress, and in tracking the progression of of hospitalised patients as well. So this is kind of the, the terminology that we'll, we'll use. And in terms of what we're trying to achieve with the basic TFAS as it was sort of first introduced, is basically to use ultrasound at the patient's bedside to see if there's any air or fluids, notably in either the, the plural or pericardial spaces, obviously plural being of more interest to us on the, the topic of today's talk as well.

This is an advanced ultrasound, and I should say at this point that I use this probably on every single patient that that I, I deal with. And I feel confident doing so and I'm happy to move forward with the results. But if you ask me to find an adrenal gland for the ultrasound, you'd need to label it before I could spot that.

So you, you don't need an advanced level of ultrasound knowledge. You don't need to be able to do an echo to be able to do this or to do a full thorough abdominal investigation. It's very specific things that you're doing.

So this is a technique that, that anybody could acquire very, very quickly. And for the TAs itself, as it was sort of initially introduced, is that you look at 5 views of the the the thorax. So, Well, the probe, position number 1 here, the terminology for this location is the chest tube site, so you put the, the probe on, in a longitudinal plane, perpendicular, the ribs about the sort of 7 to 9th intercostal space, and you do that on the left and the right, and that's termed the chest tube site.

Number 2 down here again, we do this bilaterally, the pericardial site, so just over where the heart would be, and that's our sort of Windows 3 and 4 if you like. And then where the number 3 is down here, this is termed the diaphragmaticohepatic site. And for any of you who are AFAST fans and are kind of using that, it's the sort of same probe location as the sort of subziphoid view, but kind of looking forward into the, the thorax there.

And you're kind of looking at these 5 sites sort of like a A regular exam, you include all of these things and you're looking for specific things at each point that we'll talk about. So in its simplest term, we're literally in the context of a respiratory distressed patient, is that we're looking for air or fluid in the the plural space with this. And this is great, and as I said, I'm a big fan of this and I, I use it a lot, but this thing has blown up, for want of a better word, in terms of how complex it is, in terms of the terminology that's evolved and On the left of this slide here are all terms that we sort of, you know, people using this regularly will band around as if it's sort of everyday language, but when you take a step back, you're like, what, what is it we're actually talking about?

So it's, it can potentially put people off by being fairly confusing in terms of the, the terminology. And then when you actually try and do it, then you end up with, with images like as we can see on the right here. And historically, we've never really ultrasounded lung because it's filled with air, we can't really see anything.

And now we're deliberately ultrasounding the chest. And so we're just not used to seeing what these images look like. So there's some potential barriers in terms of, getting started with this.

But, what I hope to show today is that this can actually be quite a sort of simple, simple thing to answer a specific question for a patient in respiratory distress. And if we start with one of those major indications looking for the presence of air in the chest, so trying to diagnose a pneumothorax using ultrasound. I should say that this, this is never going to replace a physics exam.

But this is potentially for patients where we're just not really sure. Maybe there's lots of things going on and things just aren't that clear cut. Maybe we're looking for kind of progress over time.

So it's not a replacement, it's, it's sort of an adjunct to what we're already doing. But ultrasound can actually be, be really quite handy for this. And The reason why is that we're not really looking for the air itself because you, it makes, you just can't really, can't really sort of image air using ultrasound at all.

But what we can do is to kind of look for artefacts and look for kind of other things to give us clues as to what might be there and In the context of pneumothorax, what we're looking at is if we consider them the, the right side of this image here, you've got a nice inflated lung. This is, this is all, all good in health. We know that we've got a layer of lora that's not coating the outside of the lung, and we've got a layer just on the inside of the chest.

And we know that in health, those two should be basically rubbing up against each other, kind of moving back and forth as the lung moves. So we know that if we see that, then there definitely can't be a pneumothorax therapist and in contact. In contrast to the image over the left here where we've got the horrible pneumothorax here, the lungs collapsed and sort of moved away from the the plural lining the wall.

They're separated by gas now, there's no contact. So we're kind of losing that, that normal finding. And that's basically what we're sort of looking for an ultrasound.

And the way we diagnose the pneumothorax in these patients is in terms of the sites that we talked about, and the image of the TFAST, we're using that chest tube site, so rib space 7 to 9 or so. And what we're doing is we're, we're putting the probe on the marker directly towards the patient's head. And the really important thing is that we're holding that probe stationary.

So normally when we're scanning, we're kind of moving around, we're looking here and there, checking everything out. Because we're looking for an intrinsic movement that the patient's doing all by themselves, and we have to stay perfectly still with that probe so we can actually give ourselves a chance to see that. So we're holding the probe and horizontally and stationary.

Maybe pivoting a little bit just to be able to get the image that we want, but it is just to put the probe on that spot, wait and kind of look for what we're, what we're meant to be looking for. And because it can take a bit of time to move around the thorax, if we have positioned the patient specifically for this, then it's important to just give a little bit of time for the air to kind of pocket and settle where we're looking, just so we're not sort of being too speedy and potentially missing something. So for those of you who haven't, aren't sort of used to, to doing this and you know, might be contemplating trying this in a, in a patient in your practise, I thought it was worth going through what are you actually seeing.

So you put a probe on and what actually do you see? And ultimately what we're looking to find eventually is to find that line of where those two plural layers of plural are connected to each other and looking for movement between them, but to be able to find that we need to sort of identify our landmarks and I, I like the, the image on this slide. So taken from one of the sort of founders if you like of of TAs.

So, just go back one. The way they sort of describe this makes, makes sense to me and takes a little bit of humour in an otherwise stressful situation. So, if you look at the image on the left here, we've got our probe here and straight away we can see these sort of 22 big shadows here, and this is basically our two ribs.

There's one here and one here with a shadow immediately but beneath that kind of makes sense the way ultrasound works. And so we know this bit in the middle is basically our intercostal space. This is the window we want to be able to look inside and, and see what's happening inside that that floor space.

And what we're looking for is this line here, which is basically quite a bright white line just a little bit below where those rib shadows start, and that's the line that we want to, to focus on. But as you can see, there's other lines up here, there's lines below there. Which, which one are we actually looking for?

And this is where I really like this description of the GAA sign. And what this says is that if you imagine that the sort of two ribs are the, the eyes of an alligator and it's got its nose just kind of a little bit above the, the water level, just looking for its next sort of prey. Where it's nose is basically just a little bit below those 22 rib bulges is the line that we want to look at.

And then if we look on the other side, we can see straight away that's that this sort of white line that we're focused on. And so if we look for the gate sign, then we know that we've got the right view to be able to to see what we need to see. And then what we're actually looking for here is is what's turned the glide sign.

And we're looking at that white line that we've just identified by by looking for our alligator in the mist there. And we're looking at this white line and what we're looking for is movement. And so this is, this is a sign that has to be done in real time.

This isn't something you can look at a still image and decide it's, it's completely dynamic. And so if we look at this video here to try and illustrate that point, you've got rib space here, you've got a rib space here, I imagine alligator eye, bridge of nose, so I draw your attention to this sort of white line in the middle of the screen here. And this will just keep on running, so hopefully you'll get a chance to, to appreciate this.

But what you should be looking for is you can see a little shimmer that comes. So if you say, I see it, see it now. There's like a little tiny shimmer, it almost looks like it could be a trickle of water and kind of running along, just a little bit of shimmer along that white line.

That's basically those two floral lines moving against each other. So that tells me that they're in an a position, which means that there cannot be a pneumothorax. So.

In in summary, the, the presence of the glide sign rules out and you must all accept that site. So you have to do it in real time as we said, but it's, it's accurate once you've, you've sort of seen that. And it's something that can really easily be learned with practise as well.

So it's something that, that can be done regardless of sort of previous ultrasound experience. Historically, pneumothorax has been sort of considered as a, as an all or nothing phenomenon, which really I think all of us as clinicians know isn't true because you see patients with a mild pneumothorax or like a horrible pneumothorax. And what you can also use ultrasound for in these pneumothorax patients is to detect something called a lung point.

And that's basically finding the point at which the glide sign disappears. So basically the point at which your pneumothorax kicks in, if you like. So, You can imagine that if you're, you're new to doing long ultrasound and you're trying to diagnose a pneumothorax, you look for a glide sign in one spot, you make a decision yes or no, and you, you might be right, but you might be wrong if you look in just one spot.

What you do if you try and find a lung point, which you'll only see if you do have a pneumothorax, is that you basically try and find, look for that glide sign standing at the top of the chest and moving all the way down. And if you, for example, in this patient over here with a partial pneumothorax, this is some free air here. You put the probe on at position one, there's a pneumothorax, so sorry about that.

So you, you don't see a glide sign. You put the probe at position 3 and you do see a glide sign because you've got lung gap position. There's no pneumothorax there.

0.2 here would be your lung point. So that would be the point at which your blind sign disappears.

And it gives you more confidence that your diagnosis of the pneumothorax is right, because if you know for sure that you do see a glide sign in some area and then you don't in another, you're pretty confident that that's actually the case as opposed to you just having missed it completely potentially if you're new to this or it's, it's a challenging patient. And that's in contrast to a patient with more of a massive pneumothorax. So there's air over this entire sort of hemihorax, you won't get a glide sign at any of these points, and that's because of the sort of extensive pneumothorax.

So for me, it helps assess any sort of severity of free air, but adds a bit of extra confidence that I was correct in my sort of judgement of of the glide sign in the first place as well. Something else that you can do with the ultrasound probe at this chest tube site as well, is instead of looking for air is to looking for sort of floor space and air, is to actually look inside the lungs as well a little bit. And some of you may have heard this terminology of ultrasound lung rockets or bee lines or comet tails.

It all gets quite creative when it comes to sort of emergency ultrasound. It turns out data signs and comet tails if it brightens up an overnight shift otherwise. But what we're looking for here, again, it's the same orientation, so you've still got your, your rib here, your rib here, your plural liner marked by the, the black arrow.

But what I would like to draw your attention to here is these sort of white lines that are just jetting down into the far field here. So you can see 3 really nice blue ones here. These are the things turn these long rockets or, or bee lines as sort of, I think more people are referring to them as at the moment.

And what these are is they're, they're basically artefacts again, but most importantly, they're artefacts that are created if you have a little bit of fluid next to some air in that sort of peripheral area of lung. And the nice thing about that is if you see these beelines, it's your third line in defence about ruling out a pneumothorax, because if you have a beeline, you definitely don't have a pneumothorax. And because to be able to see a beeline, you have to have your two pleura completely opposed.

So again, it's sort of like a final check to see if if the pneumothorax assumption was right or not. But beelines themselves have some extra utility. So again, coming back to its trauma origins, if you see them, it implies that you've got fluid mixed with air.

So, it's often referred to as a wet lung, because it implies the presence of fluid in there. And in a trauma patient, that basically means that represents you've got pulmonary contusions. And that stands true in our veterinary patients as well as in human medicine.

If you see them in a non-trauma patient, so like the average patient in respiratory distress, that tells you that you have wet lungs, so you have fluid in there that shouldn't be. So it could be heart failure, it could be pneumonia, it could be, you know, it could be pulmonary haemorrhage, it could be any number of things. It doesn't tell you exactly what it is, but it does tell you that you have some alveolar disease.

So, again, kind of quite useful to, to look for these beelines to, to fill in the info a little bit more. And this is, is gaining momentum. So this was a study published in JVIM recently 2017, where people are starting to look at the use of this lung ultrasound in various different conditions to see, can it be useful?

Is it better than what we already have diagnostically? And this study looked at lung ultrasound in dogs with various stages of chronic valvular heart disease who, you know, some were going into congestive heart failure. And traditionally, we've relied on X-rays to look for the presence of pulmonary edoema.

And what this study did was they said, well, is lung ultrasound as good, worse, better, and where do we lie with that? And it basically showed that in dogs with stage C valvular heart disease that had radiographic signs of pulmonary edoema, 90% of them had these beelines had this evidence for wet lung. .

They have the various other things in here. So a sensitivity of 90%, specificity 93%. These are pretty good numbers for a non-invasive, quick bedside tests that should take less than a couple of minutes as opposed to taking a dog to X-ray and all of the potential stress that that might involve.

So it shows that this is, is definitely gaining interest and, and is that probably explains the more that we use it, the more we find. And so it's definitely something to potentially look at in the future. What they did in this, this study is in case you're interested, is that they had some nice picture guides as to how they were sort of categorising these patients.

They were trying to say how severe these bee lines were to kind of try and make it a little bit more accurate, but I thought for the purposes of today's webinar, it was quite a useful kind of image from their paper to show because it just shows the sort of difference as to what you might expect. So figure A being can't really see any bee lines at all, nothing really to see. Next stage along some kind of rare bee line, so class as less than 3 per intercostal space.

We've got one convincing one here, one convincing one here. See getting a little bit worse, so numerous, so greater than 3, so you can see what here 1234, maybe 5 over there. And then the kind of the worst case scenario is when there's so many, they're all blended together, they're so-called confluent bee lines.

So. So it useful to kind of show the, the difference, difference of severities that we might see but potentially might help us with our sort of medical record keeping to sort of communicate how a given patient looked. The other kind of major aim of the TFAST is looking for pleural effusion and the site, the sites of TFAST that we typically use for that either the pericardial site or on either side or the diaphragmatic or hepatic the.

And what we'll really do is looking for fluid, which these images show quite nicely down here. We've got this hypoechoic little sort of pockets of, of fluid from there, and some all the way around here. But what we want to make sure that we do is we don't get too sort of diagnosis happy using this sort of new gadget and we're not overdiagnosing things because it is surprisingly easy to confuse this with some pericardial effusion and or even potentially enlarged cardiac chambers, and we definitely don't want to start sticking needles and things if, if that's what we've seen by mistake.

So, The key thing to kind of pick up and make us confident we're seeing pleural effusion is that we know that plural food isn't contained, so it shouldn't be within something like a, like a sort of chamber wall of the heart, for example. And it's generally triangular or angulated, which again, nothing in sort of normal biology is, so that would kind of clue us in there's something unusual going on. And we should also verify that we've seen it on multiple views and a sort of a, a safe feature, so it's not just one shot that we might be misled by.

We've seen it repeatedly, we're more convinced. And something I, I like to do to make sure I'm not confusing this with pericardial effusion is if I adjust the depth that I'm viewing the image at, so I've got the whole heart on the image, then I can see all the way around it and it just really, that just helps me distinguish pericardial effusion from floral a little bit more easily. And so that and looking for more triangulated angular things are sort of really good ways of making sure we're looking at the, the right thing.

We did say that this was quite an evolving, rapidly evolving thing. So, whereas the origins of AFAST were quite simple, to look for air or fluid in the plural space or pericardial space. Lung ultrasound by itself, so exploring these bee lines a little bit more and various other things has, has really evolved and become quite popular.

And so the next kind of development that we're kind of in at the moment is this so-called vet Blue exam, which stands, I guess the blue origins come from cyanosis, so it's quite sort of topical, but the vetBlue stands for the veterinary bedside lung ultrasound exam. And what we're doing here is it's basically doing lung ultrasound at 4 points on each side of the chest, so 8 different little acoustic windows for us to look at the lungs specifically in. So again, looking for those various artefacts to tell us what might be going on.

And this is kind of shown on, on a patient and on a sort of corresponding X-ray so we can see where we're going. So we'll generally start over here this, this region's turned the cord of lung lobe and it's actually where you'd put the probe on your chest tube site. So it's exactly the same starting point.

You'd then steer with your probe down towards the elbow and and midway along there you'd stop and this would be the perhyla lung region, and then you'd end up with the middle lung lobe region. And then you'd go a little bit, you'd move the limb forward a little bit cranially and go forward and that will be your cranial lung lobe region. And you do that on, on both sides of the chest.

On both sides, you'd be looking for anything that was any air or fluid that shouldn't be there, but you'd specifically also be looking at the lungs and specifically how many beelines you saw, and you'd be counting them as to whether there was 123, greater than 3 if they in confluent, etc. So you're basically drawing a sort of picture as to how the lungs are are looking in terms of whether they wet, are they dry or other. And so what you can basically create is this sort of like image up here so you can say, have sort of the recording charts if you like to say the, the prevalence of, of the lines at each of these four sites and sort of on, on both sides of the chest as well.

The really important thing to say about this is that it only provides information on peripheral lung changes. So you're only really getting between the sort of the out of 1 and 3 millimetres of the lung. So if you find an abnormality, then yes, it's significant, but the absence of something doesn't rule out a problem with the lung.

So it's, again, it's not a replacement for the diagnostics, but it's maybe an early heads up. It's maybe a way to kind of get to things a bit quicker than we, we would have before as well. And it's also just just a sort of side note that these petBlue sites are, are, are regions and they don't correspond to a specific lung lo just in case there's any sort of confusion because it is something that could otherwise and kind of raise a few questions.

These relate to regions as opposed to the actual underlying anatomy. There are various signs that you might see when you're doing this lung ultrasound in more detail, and again, this wouldn't be something I'd necessarily be picking up the first few times I did this. It's a sort of more stuff that you'd evolve to see over time, but What you're really looking for is anything that deviates from that normal normal kind of gator sign that you'd expect to see.

So sort of depicted on this image here. This is normal. The step sign is referred to as if you have this sort of disruption of this normal linear continuity, and it basically tells you that there's a problem within either the thoracic wall or the floor face and a trauma, you might worry about rib fractures or a diaphragmatic hernia.

So by itself, it tells you there's a problem and, and again, just really suggests that you probably want to do some additional imaging. Where you can look at the lungs in a little bit more detail is by looking at these sort of next couple of signs. The first of these is is termed a shred sign.

And what we're referring to here is if you have consolidation along with some air in it still, so there's fluid in there for sure, but there's still some air at the same time. And what you see here is that, again, there's an inconsistency in this sort of normal gate sign that you'd see. There's this other stuff that's kind of lurking underneath.

And you tend to see this sort of hypoechoic echo pore tissue in there. This is sort of the actual image of how you'd see it just doesn't look like that sort of normal view that we saw. And that tells you there's some peripheral lung low consolidation.

There's some fluid in there. Again, it could be anything, it could be cancer, it could be tars, it could be blood, it, you know, it could be edoema, but it tells you there's something there and so it prompts sort of further thought, further investigation. And of course, we know lung consolidation can progress to the point where there is an aeration present.

And if that's the case, it looks a little bit different ultrasound, it's termed the tissue sign. And this is something that's also termed, hepatization of lung tissue, and you basically put the probe on and you think you're in the wrong place, and I've, I've done this before. You put the probe on and it all looks a little bit dense there and you think this doesn't look right, and you wonder, you know, is there pleural effusion if your settings aren't right, or you look and you think, I'm over the abdomen, that looks like liver, and then you realise, actually you're over the lung and that's actually lung tissue itself without air, so you can see it as tissue itself.

And if we see that again, that represents pretty significant alveolar disease and again tells us that there is a lung problem, we can go and investigate that a bit more. And people, this is starting to evolve. There are people who feel confident that they can diagnose lung masses themselves, the so-called nodule sign.

There's some new stuff coming out with people being pretty convinced that they can see pulmonary thromboembolism this way. I'll be 100% honest and say I don't feel I'm there yet personally, and I don't want to jump on the wagon or something and then overdiagnose things that isn't appropriate. So I think it's something that is constantly evolving, but it's, it's a non-invasive technique for these patients with respiratory distress is certainly very interesting.

And what we're essentially doing with this blue strategy is trying to build up a sort of pattern as to what we're seeing in the lung. So the normal lung at each of these four sites, we should have a dry lung, so it's delineated by D, with no bee lines or anything abnormal. So normal, normal lung makes sense should be normal at each of these, these four sites.

In contrast to, for example, one of these non-cardiogenic edemas, that's got radiographically, we'd see called a dorsal and pulmonary, pulmonary infiltrates, and on a, on a vet blue, we'd see sort of wet lung in those two regions and dry in other places. So it's almost like you're drawing your own X-ray in your mind's eye as you're sort of doing these scans and Other examples here, a cardiogenic edoema would have wet lungs sort of focused around the perihal region, and pneumonia would have more cranio ventral disease, etc. Etc.

So you're sort of, you are building up your own diagnostic. And just to finish up, just wanted to finish with, sort of one of the major questions is regardless of how much information we get from physical exam, from ultrasound, is trying to figure out if, is it cardiogenic, basically. And we might look at the signalment, so, you know, this, this very guilty looking dog here, a dog of that breed will, you know, potentially have the medical notes to say this is a long term heart patient, etc.

You know, there might be big clues to tell us it's probably cardiogenic. We might be suspicious based on our assessment. There's, there's, there's wet lungs, there's common crackles, there's space disease, etc.

Or there might be auscultation findings to say, not to rule it indistinctly, but if there's a raging heart murmur, if there's a cat with a gallop rhythm and a regular heart rhythm, they might all be pleased to say, well, the heart's abnormal, and then think, could that be related to the respiratory signs. Heart rates themselves I find a little bit trickier to, to differentiate. So cats with heart failure would tend to be bradycardic, but can be tachycardic, so it doesn't rule it in or rule it out 100%.

And any shocky cat generally will be bradycardic. So again, it's not specific to to cardiogenic disease. And dogs with heart rates, I usually have the cut off 200 beats per minute.

If the heart rate's over that, then there's probably an arrhythmia because that's too high for any sort of compensation in another form of shock. But again, there's sort of, there's always that case that's a bit borderline that we're not entirely sure of. So a physical exam might be a bit, might not give us the the entire answer.

And this is where this ultrasound can come in. And so if we see that a patient's got wet lung, it's got confluent beelines or lots of beelines all over the place, then that tells me that there's something in that lung and If we take a cat, for example, in terms of alveolar diseases that cats get. It's not common that they'll present with pneumonia or metastatic lung disease.

If they have lung disease, it's probably either asthma or it's, it's heart. And so if they've got wet lungs, then I'll say, OK, it's probably hot. If it's dry, then I'm thinking more asthma.

So it might help that sort of decision making to steer us in, in one direction or another. And again, with, with dogs, like we was doing that mapping with the vet blue, we might say that the distribution is consistent with pneumonia or something similar. So, It might rule things in, it might rule out other things that sort of narrows down our list, so that could be useful as well.

And as sort of clinical tip, we can look for just how they respond if we were suspicious, we gave them frozenide, did they get better? Did they not? So that's something else that can help differentiate between the two.

And then the very last thing to say is that we've focused on ultrasounding the plural space in the lungs so far, but you can also get some information from the heart. And this in the context of trying to figure out if respiratory distress is cardiogenic or not, this can be quite useful. And learning how to approximate the left atrial size is probably the most important thing.

We're comparing that to the size of the root of the aorta, so it's termed the LAAO or the left atrial to aortic root ratio. And it basically tells you if your left atrium's enlarged, then it makes it more likely that you've got cardiogenic signs. It's easy to measure with practise and there's discussion about what's normal, which is never a good starting point, but generally speaking, I say the normal ratio should be around 1 to 1.

If it's greater than 1.5 and the left atrium is 1.5 times bigger than the aorta, then I'm, I'm pretty suspicious that's abnormal.

But the more of these you do, the more of these, you build up a picture. So it can be, it seems like it can be quite helpful clinically. And this is something that there was a paper that just came out last year that was a, a really nice paper looking at how do we diagnose congestive heart failure in cats with respiratory distress, so very topical for today.

And they looked to see how accurate lung ultrasound and looking at the heart as we've just mentioned, was versus measuring sort of blood antipro BMP for a sort of final diagnosis. They had 51 cats in, in respiratory distress. And the paper shows some really quite nice images.

Again, the sort of variable amount of no bee lines, a few bee lines, confluent bee lines, some pleural effusion with bee lines and just some pleural effusion over here. And also shows various focused cardiac ultrasound, so kind of normal left atrial size and subjectively enlarged left atrium here and enlarged left atrium compared to the aorta with some pericardial effusion. And their results, to finish on, I think were really interesting and certainly for me add some strength to the use of ultrasound in these emergency patients because they found that using these lung ultrasound criteria to say that if you had more than 11 of these 4 sites strongly positive for bee lines, it was pretty suspicious you had congestive heart failure.

And also the sensitivity for looking at left atrial enlargement was incredible considering this is being done by normal people. This isn't, you know, being referred for an echo to somewhere. This is people taking a peek and subjectively looking at the size of the left atrium, 97% sensitive, 100% specific for congestive heart failure.

And so their conclusion was that point of care testing is useful to diagnose congestive heart failure, and then I think I would have to agree. So. Hopefully that was interesting.

Hopefully that adds a few points of, it's certainly something interesting to look at and with a bit of time we've got, I'm more than happy to take any questions you've got. Lindsay, that was more than just a little interesting. It was bordering on mind blowing.

It's amazing how the advances keep going and, and how, you know, how things which 10 years ago were, oh well that's not possible are now becoming, actually, you know, as you said, and I love your term, normal people. I presume you've excluded specialists out of that group, hey. I have excluded specialists, absolutely, just the nice normal people.

But it's just amazing how how us normal people can do these things where before it used to be, well, we'll refer it to the specialist and they may be able to do something. So that's absolutely fabulous. Exactly.

I think I'm almost talking myself out of a job, to be honest, because this is stuff, I mean, the problem with respiratory distress is that you, you have to make a decision where you're at. And, you know, that initial stabilise mean if they're going to get sent somewhere, they generally need some work before they can, they can travel. So I think it's great that this stuff is, is practical that we can use at any, any point, really.

Yeah, I think it's great. And, and, you know, for the folks attending this, they don't know that that my clinic refers to you. I, I can guarantee you're not putting yourself out of a job.

Good, good. My boss will be happy to hear that. So the question that we spoke about earlier before, I think you've touched on that.

Sue wanted to know about the emergency use of bronchodilators, and I think you touched on that. I don't know if you want to add anything to that now. Mm.

I think, I think in all honesty, I'll use them if I think that there's lower airway disease. I think if there's anything else, I'm, I'm, I generally don't, to be honest. So I think this whole approach just helps me say when it's definitely going to be useful as opposed to when I'm just kind of giving them hoping for something, but they're probably not gonna work.

If you're not sure in a cap, absolutely go ahead and give them a, you know, a sort of one-off dose isn't going to be the, the end of the world at all. But hopefully we can be a bit more targeted with it now. So hopefully that helps.

Excellent. Gabriella has asked a question and it, it echoes a couple of other questions. So excuse me, Gabriela, if I'm gonna paraphrase your question.

But the positioning of the patient for the TFAST and specifically related to dogs versus cats. Mhm. So the good news for this is basically choose the position you like.

So, whereas with other things, you know, they'd have to be in right or left lateral or whatever, this can basically be internal, it can mean standing, it can be in lateral. So it's, you probably have to move the patients to be able to get to the different sides of the chest, but it can be, however, they're, they're happy and sometimes, although it's nice to have a sort of a full exam. In a patient with really bad respiratory distress where, you know, you've just got a little window of a few seconds where, you know, they'll tolerate it.

Just having a look at some of those views, it might help you rule out something which at least make sure your list of things a little bit shorter at least. So, however they want to stand or sit. It's fine and then whichever the windows you can practically get to and it's it's something that doesn't have to be all or nothing at that point in time.

You can do a bit now, you can check on it later. It's a really good tool for tracking them over time as well. So if you don't get all of your views at once, no big deal, you can always come back to it later as well hopefully.

You also mentioned that you don't clip the fur when you do these. Do you wet the skin with anything specific or any tricks and nuances to get the, the better picture? Do you know, in, there's, there's a few, few different ways different people do it.

So I, I tend to sort of just part the fur and use a little bit of ultrasound gel. But if you have a protector for your probe and just sort of wetting the fur with some alcohol, I think actually probably gives you the best contact. You just need to make sure you're not dissolving the rubber on your probe and, and shortening the, the lifespan of this as a diagnostic in your practise.

But I think that one of those two is probably adequate. It's nothing to say you can't flip the fur by any means, but it's, it almost looks like a bit of a patchwork once you've kind of done your vet blue assessment, which, you know, isn't life-threatening, so not that big a deal, but it's usually not necessary. I should say that some, there are some people who do an almost up and down technique.

So instead for the vetBlue, we talked about those 4 sites. Some people basically track up and down every single intercostal space, so kind of like a, a giant radiator or something if you like. But I feel like if you're using that just becomes too messy for my liking, there's a lot of alcohol around this, you know, I start worrying about the health and safety of it.

So I, I tend to just be a bit, I tend to use those four sites and just use some gel. And also, I mean, if we consider the fact that this is an emergency screening, you don't want to be spending 45 minutes trying to evaluate these cases with this technique. Exactly, exactly.

I think, yeah, you're spot on there. And to be honest, I mean, we've been talking about respiratory distress today, obviously, but in the, in the average sort of emergency admit will often be doing this as well to kind of screen for, you know, left enlargement, lung problems, etc. But really, we should be looking, if you're looking at the abdomen as well as chest, doing the whole thing in sort of less than 2 minutes once you become sort of practise at it and you've kind of got a plan for what you're doing.

So, yeah, but if you, if it takes too long, it's just losing its power, so it should be a really rapid thing. Last question before we move on to the next section because I'm aware of the time here. Hannah wants to know, would you also expect to see beelines on ultrasound in cats with pleural edoema, with pulmonary edoema, sorry.

Yes, you would absolutely. So that's the really nice thing about the beelines just tell you if there's wet lungs. So if there's fluid that shouldn't be in there.

So whatever the fluid is, it should show up as a beeline. And what's quite nice with them if you're doing this sort of technique on cats with congestive heart failure is you see the ural effusion, you tap that, and then you can actually see what's left behind a little bit more easily. So it can be a sort of follow-up diagnostic as well, but yeah, absolutely, you'll see beelines with pulmon edoema, dogs and cats.

Excellent. Loads of comments coming through saying thank you. What a great talk, so helpful, very practical.

Many thanks. Fabulous and so it goes on. So again, big round of applause there coming through Lindsey.

If you're OK, can we proceed into the next section? Are you OK with going straight. I'm gonna be quiet and hand it back to you.