Hi, thanks for joining us. Today we are going to talk about management of those very, very scary respiratory emergencies and hopefully make them just a little bit less scary. My name's Sarah.

I'm a specialist in emergency and critical care in small animals, and I'm going to be the voice in your ears today. So what we're going to discuss is initial management when the dys patient comes through the door, methods of oxygen supplementation. I'll probably skip through those fairly quickly because I'm sure you know all about them.

Then we're going to talk a little bit about the priorities of diagnostics versus treatment in patients that are vulnerable and potentially likely to arrest. Like choosing what to do next is, is sometimes the toughest choice in these patients. We'll talk a little bit about monitoring respiratory patients and then management of specific conditions.

Again, I'm not going into long-term management, but what you do, when these things come in the door in your first sort of few hours to 24 hours of management. So the most important thing if patients are in respiratory distress is not to stress them out. Basically, anxiety, too much handling, all that, malarkey can increase your respiratory rate, increase your respiratory effort, and we don't want to do that in dysic patients.

So we want to handle them gently, if possible, keep them in sternal recumbency. For most cases, sternal recumbency is the best, . Best body position because they get the maximal expansion of both lungs, if they do have unilateral disease though, you can place the affected side down in lateral recumbency so the good lung gets the best chance to expand.

You can see this dog, is in sternal recumbency. You can see how abducted his elbows are. He's really struggling quite hard to breathe.

You might think that he looks like a reasonably happy panting dog at first sight, but when you look at his eyes and you look at his elbows and you look at the way he's sitting, he's actually got quite a lot of respiratory effort. So initially, don't jump in and start putting in catheters and get your stethoscope out and jump all over your patient. What you want to do is watch them breathe because it makes a big difference in terms of where you can localise the disease.

Process to how severe the disease process is, what you might do in terms of therapy and treatment, and diagnostics, just by watching them, and you can also see how severe their dyspnea is. So watch their respiratory pattern, watch their respiratory effort. If it's a cat in particular, if it's just come out of a, you know, out of a car trip, the best thing to do is pop them straight into an oxygen cage and don't even examine them for a little while, just pop them in oxygen, because just being in the car is stressful enough for some cats.

Let them get some oxygen into them before you even listen to them, and you can stand outside the cage and watch them, and see what their respiratory pattern is. Sometimes, it's not difficult to tell. How severe?

The respiratory distresses, cats don't open mouth breathe, that often, in this case again. He's internal, he's got his abducted elbows, he's got a rapid shallow breathing pattern, he's got open mouth breathing, and he's staring at the sky, and he's gonna rest in about a minute. This is a cat, if you see it looking like that, then you're actually running to your crash cart to get your intubation gear and something to anaesthetize it with, because this is a sign of extreme respiratory distress in a cat.

Don't try and handle this cat too much because if it can't breathe it'll freak out, and the old saying is that cats in respiratory distress will try and kill you before they die, and believe me, it's true. OK. So as we're looking at them, we assess their breathing pattern.

Is it rapid and shallow? Is it slow and laboured? Is there a lot of chest movement?

Is there not much chest movement? And then you're allowed to put your hands on them. You can check the mucous membrane colours and see if the colours, colour, and see if it's pink or red or blue or white, and then you can auscultate the chest.

We auscultate the chest on both sides for lung disease, cranially, cordially, dorsally and ventrally. Think of the chest as a tic tac toe board, and, you want to hit every segment, to see, mostly if there's differences in lung sounds from one area to another. Are they loud, quarto dorsally and soft, cranioventrally or vice versa?

Are they worse on the left or worse on the right? And we can palpate pollsters, we're looking for other, you know, signs of shock, was it trauma, is it heart disease, all those kind of things, so cardiovascular assessment as well. And our goals of this initial examination are to assess the severity of the respiratory distress and to start to think about localising the disorder.

Is it upper airway, is it the lungs, is it cardiogenic, is it one-sided or the other? Those kind of things. So now I'm gonna go through these one at a time, mixed membrane colours, there's the tic tac toe board.

Feel our pulses, and then we get on to oxygen therapy. So the easiest way to give oxygen, when you need to examine the patient is using flow by, which is just the oxygen tube, under the patient's nose. Sometimes they don't like the, the, stream of oxygen floating at them and it doesn't work, but most of the time, if you don't do it too high, they're pretty OK.

In this case, we've used a mask, and you can see the important thing about using a mask for initial oxygen therapy is we're not, it's not like using it for anaesthesia. We don't want to enclose them in it. We want to use a nice big mask that they can rest their head in.

It's not like an enclosed chamber, it's just something where the oxygen, they can have an increased, Oxygen in the environment around their nose. So nice big masks so that they don't feel trapped with oxygen going into it, and then you can examine them. Nasal prongs are an excellent thing for initial, Oxygen supplementation, they're just the human nasal prongs, and you can get them from any human, medical supplier and some veterinary suppliers now, I think, and they're not great long-term.

I don't recommend using them as your primary method of oxygen sup supplementation long-term. But initially, they, you know, if you're limited on stuff, or even if you're not, you don't have to have someone standing there holding oxygen if you can pop some prongs on, and just again increase the amount of oxygen flowing around their nose. The prongs don't have to be in their nose, and if they're really annoyed by them, I sometimes cut the little prongs off, just so they've got just two little holes with oxygen next to their nose.

A nasal oxygen catheter or cannula, actually goes into the ventral meatus and up to somewhere around the medial campus of the eye, so into the nose, and that can be more of a long term indwelling oxygen, supplementation. Really useful in long-nosed dogs, less useful in short-nosed dogs and short-nosed cats. Oxygen hoods can be used for recumbent patients that you need to examine or that are too big for your oxygen cage, or that you, patients where nasal oxygen isn't recommended.

In this case it was a head trauma patient. And we don't want to put, nasal catheters in head trauma patients because sneezing increases intracranial pressure. But anything that you need to examine and put in a higher oxygen environment, the oxygen hood is quick and easy.

Make sure you leave gaps for CO2 to get out, and they're quite effective. They don't work so well once they start moving around, but they're great when they're recumbent. The oxygen cage is useful for cats and small dogs.

The problem with small dogs that pant is that they can get very, very hot. Which is a problem because then they pant more. But they're useful, because they reduce noise.

You can put cats in there with litter trays and let them move around. They're not, restricted. The downside is when you open the door, you let all the oxygen out.

So they're really a place to put your patient and watch it, and not to be going in and out every 5 minutes, otherwise they're not doing the job that you want. A tracheal cannula, I'm gonna talk about a little bit later. They're actually, really easy to place.

It's not the same as a tracheostomy, it's just a catheter or a feeding tube put into the trachea, and dogs cope with them remarkably well, if they're getting sick of nasal oxygen, or you can't place the nasal oxygen. So I'll talk about them a little bit later. Tracheostomy is indicated if there's a severe upper airway obstruction, and they can't Get enough breath in and out, so it's not just oxygen, it's actual an obstruction so that they can't breathe, there's not enough ventilation, then they need a tracheostomy.

And if they're in severe respiratory distress, sometimes the best thing that we can do is intubate them and, maybe put them on a ventilator, sometimes just relieve, the upper airway obstruction, sometimes just give them the chance to get some 100% oxygen for a little while, take control of their breathing, and then see what we can do to help them. So your patient has come in and you've watched it and you've assessed it. It's on supplemental oxygen, but it's very anxious and it's breathing very hard, and because it's breathing very hard, it's making it more anxious.

So in some cases, sedation can be really helpful in respiratory patients. So calmer patients will breathe more deeply and more slowly, and that's really what we want. And it does reduce the anxiety associated with low blood oxygen.

But the downside is patients that are requiring conscious effort to breathe, that are severely dysmic and only focused on their breathing, if we sedate them too much, they can actually arrest because we take away that conscious control. So, having scared you. My primary sedative for most respiratory patients is burophenol.

It's fairly benign for the cardiovascular system. You get fair to good sedation, but it's not too deep, and there's minimal respiratory depression with it. So, as far as safety goes, it's one of the safest.

Obviously, any sedation can be effective, and it's dose related and all those kind of things, but, it would be my go to for most respiratory patients. In people and in some dogs, morphine has been recommended for congestive heart failure, specifically, it gives fairly good sedation, it's obviously a very good analgesic, but it's used in congestive heart failure because it also causes pulmonary vasodilation. And this has not necessarily been proved in the other opioids, although I think that fentanyl also has this effect.

Obviously, the downside of morphine in respiratory patients is that it can cause vomiting, and vomiting, and breathing hard and not a good combination because it increases the risk of aspiration. So I don't use it all that often, but you should know that it's quite often used in people with congestive heart failure. Fentanyl is what I would recommend for trauma patients with dyspnea.

Again, you get fair to good sedation. You can get quite deep sedation depending on how high the rate you put it on. The nice thing about it, is that it's a CRI, so you can increase or decrease the dose, and change the level of sedation, fairly rapidly.

It's an excellent analgesic and it rarely causes vomiting. Minimal pulmonary vasodilation, so you might not get that effect with the congestive heart failure, but mostly, like I said, we're using it for our trauma patients where we want a new agonist opioid, but we want to be able to adjust the level of sedation. And for my upper airway obstructions, I quite often use butrophenol and Aceromazine.

In upper airway obstructions, I really, want to sedate them quite heavily because they're so anxious, it makes them breathe so hard. That they can't actually physically get enough, air into their lungs. So a nice, a nice dot of burophenol with a little tinge of Ace, and is quite effective for those guys.

I don't give ACE to patients with, pulmonary disease or pleural disease or anything really other than upper airway obstruction for this. Because again, it's a deeper sedation and it can take away that conscious control, but I like it in my Labradors with laryngeal paralysis. Once you have them on oxygen, you've probably given them a little bit of burophennol, and then you need to identify what is your next priority.

If it's a freaked out cat, is it best to put an IV catheter in it? Is it best to, if you think that it's got pleural effusion, should you just tap it and try and make its life easier? Should you do imaging?

Our goals of initial management are to relieve the immediate distress, and then to localise disorder because we want to obviously manage the, primary problem, but we want to not kill them in the process, so step one is, give them a minute while you think about it. Certainly if it's a big dog and it's on the floor getting it supplemental oxygen, putting a catheter in is not that big a deal. If it's a cat that you put in an oxygen cage and is freaking out, then it needs to allow its sedation to have some time.

It needs to allow its oxygen to have some time before you try and hold it for a catheter. And you might not even want to hold it for a catheter, Before you do something else, so when to do each of these procedures will depend on your individual patient and how well they're doing. Imaging is something that is very useful and in some cases mandatory for respiratory distress or respiratory disease, but it is never, ever.

Ever, the first thing that you do. Oxygen, sedation. You may or may not want to do some imaging.

Basically, if you think it's got severe enough pleural effusion that it's disn, you probably don't need to image it. You can stick a needle in it and tap it. I know a lot of you won't be confident enough to do that, and you can put an ultrasound probe on it, or you can take a quick lateral X-ray if there is oxygen in your radiographs, and after you have given them time to, Settle and have oxygen sedation, but you're not going to, take them and do 3 X-rays, and you are never going to turn them upside down for a VD if they have respiratory distress, just never.

They always get a DV view. And sometimes, if they're distressed and you don't want to put them in lateral, you can have them sit and just have a DV view and at least get some idea of what you, what's going on. But mostly you need to trust your physical exam.

And not rushed to imaging. How we monitor them, is mostly leave them alone and watch their respiratory rate. Respiratory rates in smaller patients should be less than 30 if they're normal, above 30 is not normal, less than 20 in most cases at rest.

But, certainly patients with respiratory disease, they're going to be much higher than that, and we can use the respiratory rate. As an indicator of whether their distress or disease is getting worse, or if it's getting better, so just monitoring respiratory rates is the basic and in some ways the most important thing that you can do. We do want to monitor the respiratory efforts.

As well, you can see in this cat, he's pretty, he's not focusing on much except breathing. He's pretty flat. He's got that inward sort of looking eyes, and he's using a lot of effort to breathe.

And you can see that when his chest goes out, his abdomen goes in. You can see that in each breath. So he has paradoxical abdominal breathing, which means we don't want to do very much with that cat at all.

He might look like he's just sitting there and being floppy and not freaked out, but he's actually struggling quite hard to breathe. So I don't want to hold him for a catheter if he gets stressed at all. And I don't want to turn him on his side and take a lateral radiograph.

I just want him to sit in oxygen, and see if that can improve a little bit, . With initial sort of time, oxygen sedation, and depending on what I hear, on my auscultation, maybe a medication or a thoracentesis. Pulse oximetry is a really useful tool for oxygenation, .

But don't spend a lot of time getting a pulse ox in a patient that's obviously having trouble breathing. If they're obviously having trouble breathing, you don't need a number. Just put them in oxygen.

When pulse oxes are really useful is if, we're not sure if they're having trouble breathing. Sometimes if they're panting and distressed, or if they're shocky, you can't really tell. If the techiney is due to primary respiratory disease or actually just secondary to concurrent disease, we want to measure pulse ox to see if things are improving, as we monitor our patients, we certainly want to measure pulse ox when we take them out of oxygen to see how things are going when they're out of oxygen.

But you don't need a number every 4 hours to tell you that, excuse me, this cat is still breathing hard, so, . And what I'm saying is it's useful, but if you can obviously see they're in distress, the number isn't important. Similarly with arterial blood gases, they're the most sensitive way of monitoring oxygenation in our patients, but in acute respiratory distress, it's more harm to hold them down and get an art gas, then there is benefit in having a number for your PO2.

So these tests are important and useful, but choose when to perform them based on your patients, rather than just some protocol in your head. This is just a video to show you, of when we're monitoring things like respiratory aid and respiratory distress. So this dog looks like a dog that's panting in its cage.

But if you look, it looks a bit worried and maybe it's just anxious that you're watching it with a camera, but it looks a little bit worried. And mostly dogs shouldn't sit in their cage and pants. It's not a normal restful thing to do.

This dog doesn't ever lie down. She sits there, she looks at you anxiously, and she has a fast breathing rate. So this is when panting is not panting.

This is real hyperventilation. And this, oops, this dog had quite severe, lung disease, severe, non-cardiogenic edoema. And so, monitoring this dog and just saying it's panting isn't helpful.

It's hyperventilating, it's in respiratory distress. It's just doing it, with fast, rapid, shallow breathing and open mouth breathing. So, just, make sure you differentiate between a normal, happy, healthy panting versus a real hyperventilation in dogs.

A little bit more on pulse oximetry, if you're going to use it, what does it tell you? It tells you about the oxygen saturation of red blood cells, what percentage of the red blood cells in arterial blood are oxygenated versus deoxygenated. Normal, they should all be oxygenated.

It should be 100%. Adequate or OK is greater than 95%. Adequate, on oxygen greater than 92%.

If you have lung disease greater than 92%, you can probably live with less than 92%, particularly on oxygen, is severe hypoxemia and severe lung disease. So we want our pulse ox to be greater than 95%, and if it's less than 92, you need to do something right now. It's measured by the refraction of light waves and it measures only pulsatile blood flow, so the measurement itself can be interfered with if the patient's moving, and the machine can't pick up the pulses accurately, so you do have to look at the heart rate on the pulse oximeter and make sure it's accurate before believing the pulse ox number.

If there's not enough red blood cells to refract light, so if they're quite anaemic and the PCV is less than 15, you won't get an accurate pulse ox. If there's pigment in the blood, methemoglobin, . Carboxyhemoglobin, bilirubin, that will affect refraction, bad diffusion, arrhythmias, and ambient light can all affect the measurements, so it's a really useful tool, but you have to be aware of the technical issues that it can have.

This is the oxygen, haemoglobin dissociation curve, and the big circle at the top of it is where we want our patients to be, and notice that our oxygen saturation stays fairly high, so a normal, Normal patient has a PO2 of about 100, so normal patient sitting up here, as you start to get hypoxemic, your partial pressure of oxygen decreases, but your oxygen saturation only decreases a little bit. This is because, as a survival mechanism, oxygen travels best when it's attached to red blood cells, so it stays down to red blood cells as long as possible. So our PO2 goes down before our SPO2 does.

Then once you start getting below 95%, You're actually starting to drop off and becoming severely hypoxemic, and by 92%, which is here, you're, you're hopping off the bottom of this. So we want our patients to stay up above 95% saturated with their respiratory disease, with supplemental oxygen, we're OK with it if they can manage above 92%, and we're not OK with it if it's less than 92. If you do feel that it's appropriate to do an arterial blood gas, in terms of your patient can handle it, and it will help you with your diagnostics, which sometimes it does, I've done a few that's helped me quite a lot, but again, you just choose your patient wisely.

The PO2 is the most important thing to measure or to, to assess. It's the dissolved the measurement of the oxygen that's dissolved in blood, and obviously that will go down before the oxygen saturation goes down, as that dissolved oxygen will bind to the red cells as oxygen starts to get, . Or starts to decrease in the bloodstream.

So it's the most sensitive tool for hypoxemia, and it's the most sensitive tool to measure improvement. It's pretty much the best tool to use in anaesthetized patients and ventilated patients because it, you can interpret your PO2 in light of the amount of oxygen they're getting as well. It's dependent on the inspired oxygen concentration.

So when I said a normal PO2 is 100 millimetres of mercury, that's based on room air. So 21% oxygen. The fraction of inspired oxygen, or FIO2 is 21% in room air, and the PO2 is about 5 times that, so about 100.

Under anaesthesia on 100% oxygen, it should be 500. So you can use the The PO2 to assess your patient based on the oxygen it's getting, whereas once you're past 100% saturated on your red cells, you can't really tell if it's, you know, there's enough appropriate extra oxygen there, you're just 100% saturated. Where you get your arterial blood gas from, usually the dorsal metatarsal artery in dogs, in some cases the femoral artery, and the femoral artery.

OK. Management of specific respiratory conditions, and again we're talking about patients that have just come in, so we're talking about the first couple of hours to the first day, I'm not gonna go into you know, longer term management or diagnostics today, this is just how do we keep them alive to get them to that stage. We're going to talk about a few different types of conditions.

And basically if you have a dog that looks like this Labrador, it needs probably a tracheostomy in this case, he had a bowl stuck in the back of his throat, so he needs something done right now because his tongue is very blue. OK, this one we might keep the sound on for. We've all seen one of these patients.

He's recumbent, his elbows are abducted. He's making a lot of noise. His temperature's probably 41.5, 42.

He's just been for a walk on a half day, and now he can't breathe. So, an upper airway obstruction, it can be a brachycephalic dog, it can be an old, Labrador or old big nose dog, with laryngeal paralysis. It can be a ball stuck in your throat, it can be, like in this, Radiograph, this is actually a dog that had rodenticide toxicity and had bled into its tracheal mucosa, and basically it only had that tiny little pencil of a trachea because the entire tracheal mucosa was full of blood from its tridenticide.

So there's lots of potential causes of upper airway obstruction. They all tend to be noisy. They have, Usually stirter, which is, I kind of want to do it and I kind of don't, but.

Heavy breathing at the back of your throat. Sometimes strider, which is more of the high-pitched noise, they tend to have a slower, more laboured, inspiratory effort. Brachycephalics are often just panting because they just can't get air any other way or hyperventilating, but usually they're just really trying very hard to suck air in.

So slow, laboured, deep breathing pattern with increased inspiratory effort. And the rate will increase if they're, as they become more hypoglycemic and more anxious, and the increased rate actually doesn't help them because they're just, the air, the oxygen never basically gets to the lungs. So anything that causes upper airway obstruction, laryngeal paralysis, and brachycephalic syndrome are the most common, congenital things, collapsing trachea, can also do it, .

But masses, swellings, foreign bodies, inflammation, anything. And it is common, to have a concurrent hypothermia. Sometimes they can overheat and then get upper airway obstruction, but remembering that in dogs in particular, the airway and respiration is their main mechanism of thermoregulation.

Once they have an airway obstruction, they can't semi-regulate and they overheat very quickly. And then we have to worry about signs of heat stress, and managing that as well. So our goals of initial therapy, he's just presented to you, he's having quite a lot of effort breathing.

We want to improve their oxygenation, we want to improve their ventilation, which means the ability to actually move lungs, lungs, move air in and out of the lungs. And to do that, in these dogs, we want to reduce their anxiety so that we can reduce their respiratory rate, let them have nice slow breaths and allow the oxygen to get past the obstruction. And we want to, if we can improve the airflow itself, and obviously manage hypothermia, not just because in and of itself it can cause systemic complications, but also because the hotter they are, the harder they will want to breathe.

So we want to get their temperature down very quickly for two very good reasons. How do we do that? Oxygen supplementation, this can be difficult actually with upper airway obstruction.

Flow by, is often enough, usually enough for most of the things we get. As I said in that slide earlier, sometimes you need to just go to tracheostomy if it's a complete obstruction. In short-nosed dogs, though, that are panting, you don't want to put them in an oxygen cage because they're either too big or they're overheat.

You can't, get nasal oxygen cannulas to stay in their funny little noses. Sometimes you can get nasal prongs to stay somewhere near the face. In this case, we tried an oxygen hood.

Which basically turned into a vomit sauna, so they can be a little bit difficult, not necessarily in the initial examination, but to keep oxygen going into them, and you have to be inventive and try a few different things. So, sedation, as I said, upper obstruction, I will sedate these and get them to breathe nice and slowly. So, depending, in the bigger dogs, Ace and butterfenol, in the brachycephalic dogs, they can be a little bit more fragile.

So I'll probably start with butterphenol and those guys, and sometimes then just if they're not coping, go straight to anaesthesia and intubation, cause sometimes, it's just too hard to improve airflow when your airway is tiny, without just taking over, but in big dogs, usually ACB2fenol is reasonable. And then we want to reduce the mucosal swelling in the trachea. Every time they breathe and they breathe hard, there's increased friction on the airway mucosa, and that causes it to become swollen, and reduces the, luminal size basically, reduces the amount of space there is to for air to So we want to reduce mucosal swelling, and we might give them dexamethasone, intravenously, 0.1 mg.

You don't need any more than that. And if, if we need to, we'll either remove or bypass the obstruction if they're really struggling, and bypassing the obstruction means tracheostomy. We manage hypothermia with cooling, intravenous fluid therapy, and then we monitor them for potential sequela of hypothermia.

And this is just a little bit more on why we want to reduce the mucosal swelling. It's a lovely little law, of physics, which basically means airflow, is dependent on the radius of your tube to the power of 4. So the smaller, the radius gets, the more that airflow is reduced.

So if we can reduce the mucosal swelling, we can improve airflow to the power of 4. OK, so I mentioned tracheal cannulas earlier, this is when you put a tube and you can use just a feeding tube or if you have something like this that's can be a, peripheral intravenous catheter. Usually I just use, a feeding tube in team stats.

But basically it's a tube that goes in, between two of the, tracheal rings. You move it down or you push it down to the level of the carina, and you Use it as a supplemental oxygen at the same rate as you use for nasal oxygen. So, the advantages are they actually don't care about having a bandage on their neck.

The incisions are really small. They care about it much, much less than having something stuck in their nose. So you can use it quite long term.

It can bypass the nose, it can bypass airway obstructions. The disadvantage, obviously, is that you need to make a little incision, and if they're wriggling and struggling, it can be difficult. And if you sometimes having the, the tube too far down can cause a little bit of inflammation, you might need to take it out if they start coughing, but I've used it a few times to great effect, in some dogs.

You put a little bit of local anaesthetic under the skin distal to the larynx, you don't want to get the larynx, you want to find the trachea, where you can hold it. When you lift their head up in dorsiflexion, you'll actually, the trachea will pop out at you, in the mid cervical region, and you can hold it, and you can feel the tracheal rings through the skin, and that's where you want to pop your, incision, little nick through the skin, . Either a catheter into the trachea and pass the tube through it or a little nick into the trachea.

And open it just like a millimetre or two with curved timostats and pass your feeding tube down, suture in place with a Chinese finger trap and, provide supplemental oxygen. What that doesn't do is allow for increased ventilation. So if they have a, so if they can't get CO2 out, so if they have a complete obstruction, then you need to go straight to tracheostomy.

If they just need supplemental oxygen and needs to bypass the upper airway, then that's when the tracheal cannula can be really useful. And tracheostomy is something where you would immediately anaesthetize them. Again, the trachea is right there when you look for it and you pop a little trach tube in it.

So most, just to go back one step, most upper airway obstructions, sedation, oxygen, and then fix the underlying problem, or in the case of your congenital deformities, get them recovered as much as they possibly can be, and manage their signs of hypothermia that can or Sequela of heat stress that can happen up to 24 hours after the episodes. So, potentially renal issues, cerebral edoema, DIC, gastroenteral, diarrhoea, or even HDE. So you want to keep them in and make sure none of those things happen and make sure they're breathing OK before they go home.

But most of the initial management will be done with sedation and oxygen. OK, pleural effusion. What you'll see is a cat or a dog with a rapid shallow respiratory pattern, and sometimes the thoracic wall will not move, even though there seems to be increased effort or a rapid breathing, you don't see a lot of movement in the thoracic wall.

And muffled breath sounds ventrally. Sometimes if they're actually really struggling, the, because the lungs have floated dorsally, you can hear increased breath sounds dorsally and you think that that's the problem. It's much easier to hear loud sounds than soft sounds.

So it's important not just to hear that they're loud dorsally, but when you put your stethoscope ventrally. Notice that you, you, you should, with the amount of effort that they're breathing, you should be able to hear something, or, you know, quite loud sounds there as well. So it's actually abnormal to not hear loud breath sounds when they're breathing very hard.

So, again, sometimes we can sort of say, oh, they're loud dorsally and not notice that they're up eventually, but we've got to notice the absence of, of breath sounds when a patient's breathing really hard. We should be able to hear them. Obviously, there's all different types of fluids and fluid that can occur in the chest, and getting a sample will be the most important thing with regards to, working out the diagnostics and what the potential underlying cause of the fluid is.

Two points there. One is, make sure that they don't look like a rodenticide that's bleeding into their chest, cause you don't necessarily want to tap those too quickly. That doesn't mean you have to do coags on everything.

It means that if they also look anaemic and hypovolemic and dysmic, and you think they have pleural effusion, then you would do coags on them. Most patients with fluural effusion won't look anaemic and hyperbulimic as well. And, the second one is if you're going to tap them to get a diagnostic sample, make it a therapeutic tap.

The very, very best thing you can do to help these patients quickly is get the fluid out of the chest. So don't just get a 3 mils. And go, now I'll work out what's going on, and then I'll treat it.

Be prepared to get 20 mL or 60 mL or 300 mLs depending on the size of your patient and the size of fluid, and make it feel better very quickly. It's the best thing that you can do for them. So how do I manage these initially?

You're gonna get tired of me saying, improve oxygenation. But we want to improve their ventilation by reducing their anxiety. They'll be a bit stressed, and these are great, candidates for Brophenol.

And we want to improve their tidal volume. And to do that, we need to get the fluid out of the chest. You may or may not, Again, if you think the breath sounds, if you're not sure if there's fluid, most of the time, once you've had one or two cases that you can hear, you will get your, your ears will be calibrated and you don't necessarily need imaging.

But these are one case where you can pop your ultrasound probe on and see fluid, and you don't need to spend 5 hours doing it. You just sit there and go, Yep, there's fluid. And you don't have to do for a chest tap, you don't have to do an ultrasound guided tap, unless there's a specific pocket, in which case it would have had chronic disease in most cases.

So if you see fluid, take the ultrasound off and prepare for a thoracentesis. If you don't have an ultrasound, and you're desperately unsure, you can take one X-ray, but make sure you have oxygen. Make sure you've, given them some time after coming in to be ready.

Make sure your radiographs are set up, and you take one view and then you're back on oxygen. And then do your chest tap. If you want to refer them, certainly you can refer them, but they will be much more stable if you tap them before they go.

It's not a difficult procedure, and once you've done it once or twice, you won't worry about it anymore. And then send the fluid to the lab or have a look at the cells and the total solids of it, and, and see if you can work out your underlying disorder. It's, easiest to do thrachocentesis with 3 people.

One person holds the cat and the oxygen. Obviously they don't need much holding. One person is in charge of the syringe and the 3-way stopcock.

You always use an extension set, or a butterfly, so that you're not pulling your syringe directly on your needle, which will pull your needle in and out of the chest. And one person is directly responsible for the needle in the chest, and basically, once they've got the needle in, all they do is sit there and hold it. Everybody else does all the work, usually the syringe person, .

So if you're, you know, trying to decide who does what, don't you syringe person. Your hands can get really tired. Anyway, it's quite easy.

If you only have 2 people, you can certainly sort it out, but you can see that 3 people makes life a bit easier. Pneumothorax, similarly to pleural effusion, there will be muffled breath sounds, usually dorsally, a rapid shallow respiratory, pattern and can have reduced thoracic wall movement, so we look at them and they're breathing fast, breathing shallow, . And the breath sounds are not necessarily absent.

They're often just not as loud as you think they should be, particularly dorsally, we can often hear breath sounds quite well because it's our biggest lung volume. So again, if you're breathing that hard and you can't hear loud breath sounds, you might hear something. But you can't hear loud breath sounds, then we're concerned about pneumothorax.

And certainly, you can use history to help you if they've been in a trauma, particularly hit by a car or, a dogfight or something like that, then pneumothorax is higher on your index of suspicion, but particularly large breed dogs, but any particular patient, if they have a bullus or a tumour that ruptures, they can get spontaneous pneumothorax as well. In which case it might be one-sided that's muffled as opposed to the other, but it's not always secondary to trauma. And again, You give them oxygen.

If I'm gonna sedate these guys and they've had trauma, then I'm going for a pure m agonist rather than butterphenol, remembering that butterphenol is not that good in analgesic. So these guys will get fentanyl. If they're a spontaneous pneumothorax, they'll get trophenol and they'll get thoracocentesis, and that's how we improve their tidal volume, is get the air out of the chest.

And then we need to monitor for further air accumulation. So particularly with air, it's, you know, it's there for a reason, something has ruptured. Hopefully, it's just a shearing injury on the edge of the lung, and it will seal itself over fairly quickly, but sometimes it's more of a major airway or it's a larger area that's been in.

Well there's multiple sort of contused areas that are injured, in which case air can build up again and relatively quickly. So we monitor the respiratory rate primarily, in these guys. And if the respiratory rate's increasing again and our breath sounds are dull again, then we go in and tap them again.

And obviously if they've been in a trauma, we need to manage any concurrent injuries. The indications to place a chest strain are a continued requirement for the brachocentesis. So if you've done, two chest taps and you've got quite a lot of fluid or air out, then you think you need to do it again, and it's probably time for a chest strain.

Or in some cases, particularly with, pneumothorax, you can't achieve negative pressure just with centesis. It just keeps getting air, and those guys need a chest strain so that you can put continuous suction on them. I would usually recommend general anaesthesia to place a chest strain, particularly if you don't do them very often, and always in cats.

You can sedate large dogs, and place a chest strain with local anaesthesia, but it's much more stressful for you and more stressful for them, so I'd usually anaesthetize them. OK, so then we get to pulmonary chimal disease, these ones that are harder to assess and potentially more likely to die than any of the others. So of course we left them to last.

You'll tend to see a rapid shallow breathing pattern. Certainly sometimes it can have quite a lot of increased effort and be quite laboured. And they often increased expiratory efforts, so trying to push air out, and you'll see a big abdominal push to get air out, but they can have a mix of inspiratory and expiratory effort, particularly if they're starting, if they've got severe disease or starting to fatigue.

They often have orthopnia, which just means they stay in that sternal position, they extend their neck, they abduct with their elbows, or they can't get comfortable. They have that anxious, inward looking facial expression and the sucked in cheeks, these cats and dogs, and all they're thinking about is breathing. And when you sculpt them, you hear increased pulmonary chimal sounds.

There might be crackles or wheezes or rales, or you just might hear them loud and harsh. If there's areas of consolidation, then certainly, you can actually hear muffled sounds. It's quite common with, for example, aspiration pneumonia, if one lung lobes full, that you can't hear any breath sounds there at all, but quite loud elsewhere.

So you can hear muffled sounds as well. So our initial management, we definitely want to give them oxygen. Sedation depends on the patient.

A little bit of burophenol is good, but again, if they're really struggling, sometimes I don't want to give them too much of anything, but I'll tend to try and give them a little bit of butterphenol, even if it's a very low end of the dose rate, just to reduce their anxiety a little bit. And then we have to decide what to do. These are the ones where, is it a good idea to take them to imaging?

Probably not. You need to do good X-rays of the lungs, if you're gonna diagnose pulmonary ranchimal disease, and, that means they need to lie quite still, and you need to get a couple of views. And so that can wait, basically.

Do they need an ultrasound? If you're not looking for free fluid, sure you can look for beelines and things like that, but You're not gonna tell your pattern of distribution of lung sort of opacities from an ultrasound, so you can do it, but don't spend a heap of time because it's not going to be helpful. If you don't find free fluid or free air, then put your ultrasound away.

Should you place an IV catheter? Yes, when they're able to cope with it. But these guys, again, with severe pulmonary prankable disease, are the ones that they're most likely to arrest, so a catheter is gonna be really helpful, but give them a minute before you do it and go gently, and if they freak out while you're doing it, just abort and put them back in oxygen.

Should you give them medication? Probably, and I'll talk about that more as we go through. And then the only other thing to think about with regards to should we give them medication is, am I going to want to get some samples at a later date when they're more stable, and maybe should I not give them particular medications just in case it affects my sampling.

And that comes into play depending on the severity and chronicity of their disease, to be honest, if it's not that severe in terms of they can manage in oxygen, until sampling can be done, that's great. If it's very severe, sometimes we give them medication. To get them through the night or the day or, you know, to get them stable enough to do anything else at all.

So things that can be in the lungs, you don't have to look at this whole table right now, but that's basically there's either fluid in there, for some reason, there's inflammatory cells in there, or there's blood in there. Those are the things that can be in there and the main differentials are going to be in our patient's congestive heart failure or non-cardiogenic pulmonary edoema. Some kind of inflammation or infection, whether it be theosinophilic or bacterial or aspiration, neoplasia or pulmonary contusions.

So if you have a patient that presents to you, it's severely dysmic and you hear pulmonary crackles, it doesn't matter what the cause is, if they're hypoxemic and they're struggling, give them rosemide, when they come in, excuse me, give them semide, because, two reasons. One is that it promotes pulmonary vasodilation. So if it is potentially cardiogenic pulmonary edoema, it helps reduce, edoema formation very, very quickly.

It's also a bronchodilator, it helps reduce hydrostatic pressure in the lungs and improve blood flow in the lungs for everybody. So just in case it will help, give them a one. I shot of rosemide.

If they end up having pneumonia, or contusions or something like that, obviously we don't want to keep them on a diuretic long term, but if they're acutely struggling and you don't know yet what they have, see how they respond to semide, it can be life-saving. If you have a cat with possible asthma, you might hear wheezing, it might have a history, it might just be a 5 year old cat that's coming in for acute respiratory distress. I'll tend to give them brophenol and bronchodilator, such as tebutyle, and pop them in an oxygen cage.

I don't use, like an albuterol spacer or something like that when they're really struggling, they'll just freak out. So I use Tobutyle sub-Q, and pop them in oxygen. If they're still struggling in half an hour, an hour, I give them dexamethasone sub-Q as well, because if they have asthma, then They, those are the medications that are going to help most rest and anti-inflammatories in a bronchodilator.

If they don't have asthma, I might have, you know, screwed up some of the sampling by giving them dexamethasone, but, I'm not gonna have really made anything much, much worse than the one-off dose, and I might have saved their lives. So these are the acute dyne. Like, potentially going to die shortly, patients, sometimes you just give them a medication in case it will help, because you don't have, they don't have the strength, or reserves for you to do any diagnostics, and you want to get them stable enough so you can do the diagnostics, and then you don't continue with the medications that they don't need.

OK, cardiogenic pulmonary edoema, everyone knows how to treat it. Oxygen and rosemide, if they need a vasodilator, you can use morphine, you can use ACE inhibitors and nitroproide. You can use Pimabendin, but it's nice to know what kind of heart disease they have, because of the increased contractility, you can make some patients worse by increasing contractility, .

But oxygen and rosemide, and I give them a little bit of time and Leave them alone. All right, aspiration pneumonia, that was my heart failure. Oxygenreide, basolate, and leave them alone.

Aspiration pneumonia are really common. The one thing to remember about aspiration pneumonia is it's caused by something. They vomited for a reason, or they regurgitated for a reason and refluxed for a reason.

So you've got to treat the pneumonia, but you have to also remember that, there's a cause, and just treating the lung disease is only treating half the patient. . It's actually a pneumonitis rather than a pneumonia in that it's not caused by an infectious disease, infectious organism, it's caused by aspiration of gastric contents or esophageal contents, and there may or may not be bacteria in it.

So aspiration pneumonitis is not fixed by antibiotics. You give them oxygen. Sometimes they need sedation.

Quite often they don't, if you can let them rest. If they can't settle, then yes, you can sedate them, but usually you just want to give them oxygen, let them rest. The problem with giving them opioids and opinol's really good at it, is that it's They suppress the cough reflex, and what we really want these patients to do is cough up the junk that's in their lungs.

We want really good mucociliary clearance, so you sedate them if they're really anxious, but I don't just sedate all of them just because, I really want them to cough. It's an inflammatory process, and so they do need fluids, and the mucus in the lungs gets more, gets thinner and less viscous, better from intravenous fluid therapy, getting in from the inside than it ever will if you try and nebulize them. And so intravenous fluid therapy is important, to make the stuff in the lungs less viscous and also to, treat the patient with its inflammatory disease.

It doesn't have to be high fluid rates, but they do usually need fluids. I don't nebulize them, you'll get different points of view on this, but the outside layer of the, The mucus and the aspirated contents in the lungs tends to be hydrophobic, so fluid just sits on top of it. And doesn't get in and doesn't make it, as viscous, which is kind of what the point of nebulization is.

And the other risk, and it's potentially a small risk in these guys, but the other risk is if you're pushing water particles into the lung, they can take bacteria and mucus and foreign materials further into the lungs that weren't previously affected. Mostly I don't use it because it doesn't help very much. If you're concerned that there is a bacterial component, and this is most often with, if they've had a chronic megroesophagus or chronic regurgitation where there's a nasty bacterial soup that's been sitting in the oesophagus that is in the lungs, then a trach wash or a bronchi bronchoalveolar va is a good idea, before starting any kind Antibiotic therapy.

And then after the trach wash, or if you're not going to do one, you can start it sooner. But just use basic antibiotic cover, such as amoxicillin, because, again, it's not a primary bacterial disease. You're just trying to prevent secondary infections, and you don't want to use a lot of, antibiotics, .

That are just gonna promote resistance in anything that does end up colonising, so antibiotics don't fix aspiration, that's my take home point. Find the cause, and you don't need to capage them either. I know that it's fun or not fun, depending on your point of view.

But the best kind of way to improve mucous ciliary clearance, and to get them to cough stuff up is when they are stable enough, i.e., that you can take them on oxygen for a little while, just taking them on little short walks, and getting them to move will increase their tidal volume, make them breathe a bit harder, make them push a little bit harder in terms of, exploration, and that'll help get stuff up.

So I can make your life really simple and take nebulization and cuage off your list of things to do, just give them fluids and maintenance or make them to half or more if they're dehydrated, . And oxygen and take them for little short walks. OK.

In terms of keeping things simple, pulmonary contusions are, are one of the simplest things to treat because you give them oxygen and pain relief. You can't fix a bruise. You can't make the bruise go away.

You can actually not really stop the bruise getting bigger over the next day or so. That's what bruises do. So what you have to do is support the patient as best you can until the bruises go away.

And pulmonary contusions are bruises. So you put them on pain relief, you make sure they have, fluids just so they don't have to eat or drink. They don't have to be on high fluid rates.

It depends obviously on the severity of the trauma and shock. Quite low fluid rates are good. We don't give them.

Shock boluses or hypertonic fluids that might increase blood pressure enough to increase bleeding in the lungs and make things worse. We just let them sit, we keep them sedated, we give them oxygen. They will recover with time, they can get better, they can get worse before they get better, and sometimes they need ventilating if they're bad enough, but they're bruises, so they'll do what they're doing and you just need to support them through it.

The other disease that's actually kind of heartbreaking because you can't do much about it. I mean, it's great cause it gets better, but it's a heartbreaking couple of days. Is non-cardiogenic pulmonary edoema, specifically in this case, pulmonary edoema is secondary to something like an electrical shock or strangulation or upper airway obstruction or something like that, which has this classic dosiccoal alveola pattern, severe dorsocoal alveola pattern.

Some people call it neurogenic edoema. I say that term for edoema that occurs after, acute head injury or seizures, . But there's no cardiogenic primary edoema.

And it happens quite often in puppies and kittens that chew on an electrical wire, and the reason that it's heartbreaking is because they sit there and look at you like that. And it takes 2 or 3 days to get better. Sometimes they need ventilators.

Mostly, they need oxygen, a very small amount of fluids, and to be left alone as much as possible. Occasionally, if they're, you know, severely dysic, a bit of risemide can help, reduce the edoema in the short term, but rizammide doesn't help, in the long term with non-cardiogenic primary edoema, it's the lymphatics that have to drain the fluid out, so it's time, basically. .

And time and waiting and looking at the sad puppy. OK. And then just to finish, sometimes I turn the sound off, sometimes, we have patients that need to go on a ventilator.

And this guy, this little girly might look like she's not, that much in respiratory distress. You might notice something specific on her nose, if you live in Australia, . But when you see her breathe, you can see only her abdomen's moving when she stops wriggling.

Only her abdomen is moving and not her chest. And unfortunately, my videoing skills wasn't very good. But this is basically, snake and venomation with respiratory muscle paralysis.

And this dog was lying there, not looking like it was breathing very hard because it wasn't. And if we did a venous blood gas, we didn't even have to do an arterial one. His, her CO2 was already sort of 66, at this point.

So this is a patient that needs a ventilator, . OK, so patients that need to go on a ventilator, are patients that can't maintain their oxygenation above a PO2 of 60, which is an SPO2 of 92, even on oxygen therapy, so they usually have severe lung disease. Sometimes it's rib fractious, sometimes it's spinal disease or intracranial disease or neuromuscular disease that's in the, dog in the previous video, but if they can't oxygenate even with supplemental oxygen, sometimes we have to breathe for them.

The other main indicator is hypoventilation. So CO2 that's above 50 or definitely above 60, In means that the patient can't physically move enough air in and out with its tidal volume, and we need to take over and do it for them. Sometimes we need to ventilate them if the work of breathing is starting to lead to muscle fatigue, so these might be patients with pneumonia or edoema, that have been breathing hard for days.

And you find that their CO2 starts to creep up because their muscles are fatiguing, and these dogs would have been hyperventilating. So they would have had low CO2, to breathe, and get enough oxygen in. And if their CO2 starts to creep up, And their breathing rate gets more rapid and shallow, that's a patient that can rest, from respiratory muscle fatigue, and they would also require a ventilator for ongoing management.

So those are the indications for mechanical ventilation. The prognosis for ventilation is much, much higher. Much, much better if they have a non-pulmonary cause, of ventilation.

So if they have intracranial disease, or snake venomation or tick paralysis, all those kind of things, then they have a much higher likelihood of getting off a ventilator than if they have lung disease. Having said that, if they have lung disease and need a ventilator, they still need a ventilator if, if you want to keep treating them and the owners want to keep going, so. It's always an option.

You just have to take into account, obviously the prognosis as well as the financial costs as well as the requirement for 24 hour care, but, They, if they're not, you know, if they can't support themselves, and sometimes we have to do it for them. So, summary, acute respiratory distress, something that comes into your clinic and is dick, mostly they're the most, freaked out, scared, and potentially vulnerable patients that you're going to get, and you need to be the calmest that you can be, and you need to take Take things really slowly and be really calm and gentle with them. And this is even to the point of when you're talking to people around them, when you're handling them, you talk slowly and calmly, like pets pick up on our stress.

So you need to basically, Calm yourself down, handle them very slowly, put them in the oxygen cage, put them on oxygen, and leave them alone and allow them to oxygenate and decide what you're going to do step by step. And between each step, give them a break, and treat them like they're fragile little creatures. And what that means is you need to choose which diagnostic tests or therapy are going to be the most important initially, or of the most benefit.

You might want to do and need to do all sorts of things. You might need to take chest X-rays. You might need to put an IV catheter in, you might need to tap them, but you just have to decide in which order and when will be most appropriate for your patient.

Thank you.