Hey, thank you very much for the introduction and thank you everyone for, for joining us today. This is one of my favourite topics, so I'll try and not get too, too excited and trying to keep to time cause there's lots of interesting stuff that we can cover. So, In this first of 3 lectures this afternoon, we're really gonna start off exploring how we can best treat respiratory distress in our patients.
And we're gonna start with the basics of that. So we're gonna start from the beginning. So just in terms of making sure we're all comfortable with how we recognise the patient in respiratory distress and how we know when to worry a lot about those patients, which are the most severe ones.
And then we'll start going through what do we do in our sort of 1st 5, 15 minutes or so, to figure out what's, what the best thing to do next is for them. So it's safe to say that respiratory distress is a, is a common emergency that we see in practise, and because it affects one of our major body systems, see the respiratory system, it is, it is life-threatening. And I'm sure if we were to do a survey of the, the people listening today, if they've ever had a patient presenting with respiratory distress, sadly die, then I'm suspecting a fair proportion of us will say yes to the, to that question.
And so that leaves us in a, in a bit of a bind because we know it's a life threatening emergency, so our instinct is to get in there to do something. But oftentimes these patients, as we're aware, are just too fragile for us to be able to do what we would ordinarily want to do with them. And so what we need to do is to try and strike a balance, and keep both sides of, of the parties happy, if you like.
And we'll talk about an easy approach to doing that, in the webinars this afternoon. So in very simple terms, to start with, how do we recognise the patient in respiratory distress? Well, I hope that we're able to recognise patients before they end up in the state that this poor cat on the slides in sola recumbent open mouth breathing.
This is a very late finding. More often, we're looking for more subtle signs, so changes in respiratory rate and effort and changes in in breathing pattern, and any deviation from that normal breathing pattern that we'd, we normally expect. So none of those initial things, particularly being rocket science at all, they're all things that we're probably doing instinctively without thinking too much about.
But we need to start thinking about other things as well that may not ordinarily cross our minds. So thinking about postural changes, about, and other markers that oxygenation is not going well. And so considering these postural changes in a little bit more detail, these are otherwise sometimes termed or opa is another term that you may have heard these associated with.
They're basically things that the patient will do when they have severe respiratory distress just to try and do whatever they can to get a little bit more oxygen in. So, This Paul Westing is showing us a few of these examples. So to put this in context, this was a dog with, with longworm who's in an oxygen cage at this point, receiving about 70-80% inspired oxygen.
So pretty much the limits of the medical management we can provide. And what we can appreciate at times and what we see in some of the patients is that these patients really can't do anything else other than concentrate on their breathing. They'll often seem quite anxious.
They can't really settle it's almost like a sensation of air hunger that's described in, in people with similar changes. And they'll also adopt bodily changes just to try and reduce resistance to to airflow, so things like extending neck, abducting elbows, and things like that are typically seen too. Some of the things that we may recognise is, in contrast to normal breathing that hopefully you or I are doing right now, whereby there's really minimal excursion of, of chest and abdomen if there is them moving together, is we might see exaggeration in those movements or, or so-called paradoxical movements will come on to, whereby the body's trying to recruit extra muscles to help with breathing, so into coststal muscles, the abdominal wall, various other things just to try and do what it can to pitch in.
Obviously markedly abnormal and and a sign of, of really quite severe respiratory distress. We do know there's some species differences in how dogs and cats with severe respiratory distress will behave. So the average sensible dog, if there is such a thing will prefer to to stand up with the elbows abducted and if they lay down, then that's, that's pretty concerning in my mind.
Whereas a cat in respiratory distress, more fragile from the get-go, but they'll typically prefer to sit in sternal and if I see them in lateral, it basically means that a respiratory arrest isn't, isn't far off. And also, well, you can see more so in cats and dogs again, a little bit of a difference is cats that suddenly start changing body position or thrashing around the cage being overtly distressed, perhaps vocalising tends to represent an impending respiratory arrest as well. We mentioned about looking at breathing patterns to, to stage severity of, of respiratory distress and this dog in this video showing us quite a nice example of this so-called paradoxical abdominal movement.
So, As we kind of take a second and watch this dog breathe in, we can see that as the chest moves and moves outward as the air goes in, as we'd expect, the abdomen gets sucked into you. You can see that really quite nicely on this lateral on the lateral view. And what that basically means, as we said, is that there's really quite severely compromised breathing.
There's extra muscles being worked to try and, and allow this patient to continue breathing. And so, it's not really specific to what the cause is, but it tells us there's, there's definitely something in there that we, we probably need to get on and find out what it is. The other thing as well I'm sure we're mostly familiar with is, is the presence of cyanosis.
So this, this horrible bluish coloration of the, the mucous membranes as this dog's showing in this picture. And again, a really severe marker, these are the most severely affected patients that will exhibit this. And what we're actually seeing by by means of a reminder is that this is actually desaturated haemoglobin that's circulating, which if you can see it with a naked eye, that that's clearly not a good thing.
And the reason that we worry about it so much is that it really represents a severely low blood oxygen level. So to put this in context, if we were to have a pulse oximeter and put that on the patient and get a reliable reading, it would be coming in at less than 80%. So clearly, very much in terms of a red flag kind of zone.
So if you see it definitely cause for concern. The only thing we need to be aware of is that this isn't the point at which we should then decide to, to intervene. This is a very late finding, as we've said.
And there's also some instances of, of patients that might not exhibit this, so notably those with severe anaemia because we need to have enough circulating haemoglobin to be able to see this. So if a patient's unlucky enough to have a, a red blood cell count of less than 15% and severe hypoxemia, then we're probably not going to see cyanosis, but I'm sure that we would be picking up concerns on these patients in other ways too. We can use objective measures of oxygenation, to try and figure out how severe any respiratory distress is.
I'm working critical career. I love numbers. I love this kind of stuff.
And sometimes it helps. So things that we'll think about doing are measuring, with a pulse oximeter, with or without supplemental oxygen, or getting an arterial blood gas analysis, we can see in the, the image here. And it's nice to have these numbers.
It's nice to be able to track trends over time and, and, you know, use that to support our clinical findings to say how well a patient's doing, but If you're anything like me, sometimes it's a struggle to get an accurate pulse ox reading at the best of times, let alone in a patient with severe respiratory distress, and it may just not be possible or achievable or practical to take an arterial blood gas analysis. So, I think for me, these are things that should be additional and this shouldn't be the game changer where I suddenly find that I need to be worried about a patient. I should probably be worried from the, the things that we're talking about otherwise this afternoon.
But can add in some additional information as long as it's not stressing out the patient unduly. If we do get some numbers to put those in context, so if we do, do get them, how do we interpret them? Well, This system figure on this slide is probably bringing back some, some memories, good or bad from vet school potentially for some of us, and looking at the oxygen, oxyhemoglobin saturation curve.
So on the Y axis, we've got percentage saturation. So in an ideal world, we should be up at 100%. And along the bottom, we've got the partial pressure of oxygen in blood, in arterial blood, I should say.
. And I put the little lines on here, so the, the purple cut off here represents what is the, the upper limit or also the cutoff and normal, if you like. So this part of the curve, we've got a pulse ox of, you know, at least 95% and a, and a partial pressure auction of 80 on on arterial blood gas. So it should be, it should be higher than that for patients breathing room air.
If it's lower than that, then already they're hypoxemic. So we can see there's not a lot of wiggle room in the system before we start getting concerned. The next line down here is what we term severe hypoxemia.
So here our pulse oximeter reading has dropped down to 90%. And this is at the point where we're really starting to worry that tissues just can't function with this low level of oxygen. And to put it in in further context, the blue line here represents cyanosis.
So this is where our pulse oximeter, as you said, is about 80%. We can see that this is way to the left of where we were getting concerned over in the, the purple and, and, and black. And we can see that that curve is just about to crash off into nothing in terms of oxygen levels in the blood.
So, the numbers can help us, but again, as we said, shouldn't replace the things that we were looking at in the patient themselves. So what do we do if we have a patient with respiratory distress, maybe one of these that we're especially worried about. What, what do we actually do with them?
Well, Paradoxically, as much as you may want to leap in there and, and do lots of stuff, and the really the key to this and probably the most important thing I can say in this first lecture is that less is definitely more. And the reason for that is that we, when I think about these patients, I'm always thinking about the balance between the amount of oxygen that they're getting delivered to the tissues, and the amount of oxygen that that they're consuming. And in health, the delivery has to exceed consumption, otherwise we're in a big problem.
When these patients come in, and you'll probably appreciate these from the ones you've seen, they, they're generally at their worst. They're stressed from travel, they're, you know, they're, they're not tolerating things terribly well. And so the amount of oxygen that they've got to play with is already lower.
They're already consuming more than they have. And so the worst thing I can, the very worst thing I can do to them is actually tip the scale, against them even more and increase the amount of oxygen they're consuming by stressing them out, triggering a fight or flight response away from me, having the stress of kind of, if it's a cat stress of noisy dogs around. All of those sorts of things are really going to tip the balance against this patient's odds.
So, Minimal handling, thinking about early sedation, which may seem like a, like a funny statement to say in a patient who's coming in with a marked, respiratory instability. But sometimes the, the stress that they're going through will actually worsen their, their breathing and, and if we sedate them, it can at least stop them sort of fighting so much and let us catch up a little bit. So, it's safe to do so, then I, I do quite like, early sedation for these patients think it makes it a bit nicer for them too.
We are gonna talk a lot more about supplemental oxygen, but clearly that's one of the most important things we can do to try and up that auction delivery that we're we're providing to them. And even in early phases, thinking about simple practical stuff we can do. So, positioning a patient in sternal recumbency if possible, because anything that can increase the amount of oxygen they're getting in has to be a helpful thing in this situation as well.
So, early approach, less is definitely more, but focusing on these sorts of things. Talking about giving oxygen a little bit more detail. So I've listed on this slide a few different techniques that we might think about using to provide oxygen to a patient with respiratory distress.
And by virtue of the fact that there's several listed here basically means that there isn't one that is gonna fit every single patient. So it's really gonna be our choice as to what we have available and what's suitable, what a patient will tolerate, and a sort of coming into making a decision based on all of those factors as well. I did want to say for the purposes of today, I was gonna focus more on the, the sort of short term oxygen supplementation, so for the patient presenting in respiratory distress.
But we do need to be aware that if this is a, a problem the patient has that isn't quickly resolved and they need oxygen for longer, then we might have to start thinking about humidifying the air and titrating the amount of oxygen down to the lowest they possibly need, so we're not causing extra injury to the lung, but To be honest, in the emergency acute situation, we're just giving oxygen and then later on we'll sort of finesse the, the longer term details. So very briefly to go over our options just to present a complete story and probably the easiest and first line approach to giving auction is is flow by as we can see with this little dog here tolerating it pretty well. It's cheap, it's, it's, it's easily done.
We've got the equipment just with a regular anaesthetic breathing circuit. Probably doesn't provide too much extra by means of inspired oxygen. We might be getting up to around sort of 30, maybe 35% inspired oxygen if we're being generous.
But I don't know if you've encountered these patients before where you try and provide them with flow by oxygen and you end up chasing their nose back and forth as they're trying to wriggle away from it. It's probably doing nothing except some harm in those cases by increasing their oxygen consumption. So if it works, it can be great.
You can, they can still be out and about. You can be doing stuff with them if you need to, but if they're trying to actively avoid you, then it's probably not the right oxygen supplementation for that patient. Up in the ante a little bit more, we can try and concentrate the oxygen that's coming at them in a, in a mask.
And again, some patients will just tolerate this, good for them. Some patients are too distressed to be able to, to outwardly do anything, and they'll tolerate it too. But I find there's quite a large middle ground of patients that just aren't a big fan of this.
They, they're in respiratory distress and the last thing they want is something, over their, their mouth and nose. So, Can provide a little bit more oxygen, maybe up to sort of 40%. Some people say up to sort of 50% if we have a, a relatively, a tight fitting mask as long as they can expire and temperature regulate, I should say that's important too.
But it might well be patient tolerance that, that limits how much, use this is to us. This dog here is beautifully modelling some, some nasal prongs, which again can be a nice way of doing things again if they're tolerated. So oftentimes what I'm doing with these patients is just trying to find a technique that the patient will tolerate and working through my list of options until I get to one that works.
These are just the disposable nasal prongs that just, fit up the nostrils bilaterally, secured in place with just the, the plastic tubing around the, the back of the head. So easy to pop on, can provide oxygen up to sort of maybe 40%, maybe a little bit more, so it can be quite helpful. But my, in my experience, they tend to get displaced quite easily.
They're working perfectly, they're in the right position. I turn around, I look back and I'm oxygenating ear or something else that isn't terribly useful. So if it works well, I've got a nice quiet patient tolerating them fine, breathing through their nose, they work just great.
For the mouth breathing patient, the wriggly patient, the patient that just isn't tolerating this, then again, probably more for longer term supplementation once we've got them over that initial, respiratory distress, hopefully. Something that I'm becoming a big fan of and, and we're using more and more is nasal oxygen catheters. So again, it's a nasal source of oxygen, but it has an important difference compared to the prongs that we just talked about.
As in it's actually a catheter that's inserted up the nose, but instead of a sort of half 1 centimetre prong, there's a catheter that extends up to the oropharynx. So, That has its use that it doesn't really matter if this patient's nasal breathing, mouth breathing, both, that oxygen is getting in right at the top of the respiratory system. And so it's gonna supplement them however they breathe.
These also have the beauty that we can provide, really high levels of inspired oxygen. So potentially up to 60-70% oxygen, which in all honesty is probably the limit of a lot of the all singing or dancing oxygen cages that, would otherwise be taking up a lot of space and, and so on in the practise. This is a really nice, nice version of that.
And then, also, the other great thing about them is that they're very easy to place. If you've ever placed a nasal feeding tube, then it's exactly the same technique. We've got some pictures to, to go through this.
But they're, they're usually, after sort of a 32nd period of placing them, they're really well tolerated by the patients and then they can stay in for the duration of their hospitalisation if they did need oxygen beyond that sort of 1st 20 minutes or so. So, something really, really useful to consider. In terms of placement, we can place one or two, depending on how bad the patient is.
But, I like to put some topical local anaesthetic in the nostril, as I think the trickiest part of placing them is to get enough of this catheter in place, that they can't sneeze out before they do, if that makes sense. And I think a little bit of topical local anaesthetic just helps me win that race a little bit. In terms of how, how far do we place these tubes, then we'll just pre-measure them from the from the nostril to the medial campus of the eye.
And I should say that the tubes that we use for this aren't anything costly or, or fancy red rubber, red rub. Tubes and you can get various catheters for this purpose, feeding tubes will do it if you've got nothing else. So just some kind of soft tube and that can go up the nose is all that you need for this technique.
So we'll pre-measure and then we'll know how far we need to insert this thing in. And then the actual placement itself, and the tube needs to go down the ventral nasal meatus because that's the one that's gonna come out at the oropharynx and the easiest way to make sure the tube's going in the right bit is to apply some pressure on the nasal planum as we can see here, in the, the top left picture. And what that does is it basically includes the other meatuses and, and opens up the one that you want.
And then the easiest way to find it, usually in one shot, it works and works so effectively, is to aim ventrally and centrally within the nostril. That will get you into the that ventralal meatus and you'll know immediately if you're in the right one because your catheter will, just, just feed without any resistance. Very rarely you might end up in a, in one of the other, passageways, but then you're not going to be able to advance that further than the length of, you know, just probably a few centimetres before you come up against resistance.
If you're in the right place, it will just feed very smoothly and, and you'll be done within a couple of seconds as well. So aiming ventrally and centrally, easy, really easy way to hit that. It then generally takes longer to suture these things in place than it did to place them, .
And probably one of the limitations of these catheters to prevent present a balanced view of them is that they can occasionally get displaced by the patient's assistance or, or intervention I should say. And so as we can see in the picture here, suturing them right at the, at the corner where they, they come out of the nose can be a really good way of doing it. So there isn't a big excess of, of tube sticking out here that they can potentially get a, a nail or or some kind of purchase behind removing them.
We just need to make sure that the angle that the tube comes out at isn't too sharp, that it kinks and potentially includes flow. But suturing it close, is a really helpful way of getting them to stay in for a bit longer. Some people prefer to suture directly.
Some people prefer to do the, the butterfly tape thing that you might have previously done with urinary catheters and things like that to secure it in. So having the tape on, you you basically put it on after you've worked out how much the tube needs to go in and that's your, your marker. And then, can be sutured as shown in the, the other images here, usually really well tolerated in the conscious patient, to be honest.
But again, it's a judgement call as to if this is unduly stressing a patient. It might not be the right type of oxygen supplementation at that time, or we might need to think about sedation if we, if we haven't already. And then once it's, once it's attached at the side of the nose, then generally it needs another attachment somewhere else.
So this dog's modelling quite nicely. We've got an attachment on the side of the face here, so well away from the eye. And other people there to bring this over the bridge of the nose and, and suture, a little further back just behind the eyes.
I'm probably more a fan of the side of the face technique, so I'm just not worried about it falling in the eyes or, or, causing any, any issues there. And then it's a case of just connecting it to the regular oxygen tubing. Sometimes having a one mil ringe, taking out the plunger can really help make a nice connector between these and the, the oxygen tubing if you don't have the right connector to hand, but it's just MacGyvering something that will will work if not.
And so this can work really, really, really nicely in in dogs. Can also be used in cats, which may be, may be a surprise to, to some of you. Again, it's the right cats.
I'm probably not going to attempt this on a fractious cat, let's be honest. But some of them can, can, cope with this really nicely. And again, if you've got one who just needs a little bit more than more oxygen than you can provide with the other techniques we talked about, this may be something to think about.
They're pretty effective as well. So, this table taken from some research looking at what the inspired oxygen levels you reach in the trachea are compared to the nasal oxygen flow rates. And we can see that you can get up to that sort of 70% that we, we mentioned a little time ago.
More conventionally, we'll probably start these patients on around the sort of 50 or 100 mL per kg per minute flow rate because they're rates that are tolerated pretty well. But we can up that as this table shows if we have a patient where we need to provide more oxygen. Again, we can provide bilateral catheters if that's what we need.
So we know that this can be an effective technique as well. We also shouldn't forget about other solutions too, so maybe he's maybe you have a patient who just isn't going to tolerate any handling, let alone us poking something up the nose. We've always got various oxygen and cages and tents and incubators, and the crow oxygen colorers demonstrate.
On the figure on the right here. So simply made with a with a hard Elizabethan colour, covering the bottom 2/3 or so, usually with some cling film or something similar and piping oxygen in at the back. It doesn't have to go through a nasal catheters this picture is otherwise suggesting it can just, the oxygen can just go in the back of the, the, the setup.
This can be quite a nice sort of portable oxygen, personal oxygen cage for them. And then the kind of the other extreme of things is if we're thinking about do we need to actually intubate this patient and ventilate them. And by, by that, I mean, it could be to intubate them and, and provide positive pressure ventilation with all singing or dancing ICU ventilator.
Definitely not for everybody. Or do we mean just intubating them and giving them a means of getting 100% oxygen whilst we figure out another plan. So we definitely have this as an option.
This definitely gives us as much oxygen as we can possibly give them. But it is more of a labour intensive thing. Typically, it's gonna be more costly as well.
So it tends to be a sort of short term solution for the, the really severely affected patients. Patients like this, for example. So I might think about taking this extra step if we have a patient with really severe respiratory distress.
So, I've done everything I can to stabilise them, and I'm worried that they're just still really distressed, that it's not fair for them. I'm worried about them getting to the point where they may fatigue and have a respiratory rest before too long. So this dog who's already had some medical management, probably this is going to be the next step to proceed with pretty quickly.
But we might also think about it a little more electively. Say, for example, we have a patient presented with respiratory distress that we've tried to stabilise and it hasn't really worked. So they're, they're OK in oxygen, but I'm not really making any headway in terms of getting them to a point of diagnosis and getting them home, and we need to do extra diagnostics.
Sometimes those patients just need to have those done under anaesthesia as sort of the safest way. So there's a few instances we might think about this, but hopefully, it's the exception rather than the rule. I thought I mentioned at this point, occasionally there are patients whereby we want to intubate them and get an airway and, and we find out that they've got something that isn't compatible with that.
So some examples listed here, and maybe the cat that comes in with some respiratory distress ends up having laryngeal lymphoma or something and we go to intubate them and we, we just can't, we have that sort of peak and shriek moment and, and there's, there's a problem. Maybe there's an issue with being able to open the jar at all. So for example, this, this tetanus patient here, or maybe this is just a massive trauma.
There's just something there that that's stopping us doing what we, what we want to do. And so there are things that we can do, staying calm is probably the most important thing that we can do personally. But just running through simple checklist to say, is the patient positioned well?
Can I see what I need to, and would suction help, or a smaller tube help? Is there something I can get down there, even if it's not the ideal tube, or, or various other things as well. So, staying calm, having a plan, keeping an eye on the time so we have an idea as to how long we've been sort of trying with these sorts of patients if we end up in this, this little bind, can be really helpful just to move on for a good outcome.
But One of the things I, I thought I'd mention in the context of this and in the context of oxygen supplementation is providing transtracheal oxygen. Which is something, it is a short term measure. It's something that's gonna get us over initial crisis, but something that can be really useful and can be done with stuff that we just have to hand around the practise.
And what we're actually talking about here is placing an over the needle catheter actually through the cricothyroid membrane and into the lumen of the trachea itself. So, It's kind of shown here. You, it's basically the area that you can feel, just after the thyroid cartilages and just before, you, you get near the sort of the first tracheal ring over here.
It doesn't have to go in at this point, I should say. It can go between any of your, tracheal rings. It just tends to be a sort of a bigger area, a little bit easier to feel, but somewhere, somewhere around the area is probably where I'd go.
And it is as simple as putting an over needle catheter through into the trachea, taking out the style and attaching an oxygen source to that. So if we have any kind of upper airway obstruction, like that laryngeal lymphoma, then we have some means of getting oxygen into the airway as well. So it can be, it's a temporary measure, and clearly but can potentially be be life saving.
One thing that is important to say is that because it is just just a a small cannula, you do need to deliver oxygen through a high pressure system. Just attaching an ambu bag or an anaesthetic circuit somehow to it just isn't gonna provide enough oomph behind it for want of a better word. So, Something like an oxygen flush and an aesthetic machine, can be used just to kind of give little pulses to get that high pressure oxygen jetted into the airway.
There are, if you find you're in the situation a lot, then, it sounds like it's the kind of place I'd enjoy working. But, you, you can get special jet ventilators and things that can do this, but for the average caseload, this is perfectly fine. You just need to make sure that you're not filling them up too much and not getting too trigger happy with pressing the oxygen flush.
So making sure you've got a 1 to 4 ratio of times that oxygen is going in versus times that air is allowed to come out, especially if we've got cases we're worried about airway obstruction and just so we're not blowing them up and putting too much air in paradoxically as well. But can be a nice and useful short term approach as well. Another example of providing additional oxygen that's growing in popularity at the moment is this so-called high flow nasal oxygen therapy, otherwise referred to as vapother, it's the sort of name of the machine.
And this is a relatively new thing. It's sort of, it's been around in the states for a while, but it's making its way into, into private practise in this country now, which is, is good to see. And what this does is it's oxygen that's provided by nasal prongs again, so it's noninvasive, but it's delivered via really special nasal and narrow nasal prongs, really high oxygen flow rates.
And what this does is it can provide, really high levels of supplemental oxygen and can actually be comparable to oxygen levels you would get with, with traditional ventilation. So a nice noninvasive way of doing that. So you can see why that's, generating quite a bit of interest.
The way that it tends to work in the simplest terms, if you imagine that you've got some nice weather, you're out in the garden and you put your thumb over the end of a, of a hose pipe that's running, you get this water kind of jetting out high velocity. And that's basically what this technology is doing with oxygen and it can do all sorts of good stuff as as listed on the slide here in terms of just helping that, that breathing work a bit better, getting oxygen in. And being well tolerated by the patient as well.
So something worth kind of looking out for as this becomes more commonplace potentially as well. But moving back to the, the patient now that we've, we've got lots of options for choosing some supplemental oxygen. What about the actual patient itself now?
How are we gonna stabilise them a little bit more specifically? Well, I think the first thing to say about that is, is in terms of treating the treatable. So they're getting oxygen anyway.
We want to try and figure out what the most likely causes, so we can start picking out what can be treated. And the nice thing about this is some of the, the things we talked about already, the breathing pattern, listening for external noise, thinking about signalment and so on, and listening to the chest or very simple things we'd be doing. But what I want to kind of talk about in the next part of, this webinar is, how do we put all of that together to try and reach a conclusion in these patients.
So hopefully we can get a lot of info from this as well. And the thing about these patients at this point in time is they've had oxygen, we're minimising stress. And they can still be really quite daunting.
And there's a lot of things that have been going on. There's a lot of different things that we could and maybe should be doing. We're not really sure what to do.
We're worried the patient can't tolerate anything we want to do with them. But this is a, a way of approaching these patients. I was taught as a resident and I found it really helpful personally to just start making progress on these patients and What it basically says is that If you have respiratory distress, and then really it can only come from a problem within a certain part of your respiratory system.
So basically the areas listed here, so the upper, upper airways, that's all trachea and larynx, all of that sort of stuff, lower airways, your, your bronchi and within the lungs themselves. Ponripaya being the gas exchanging units, your little alveoli hanging out there, hopefully getting the oxygen in into the patient, your plural space. Your chest wall and diaphragm so kind of mechanics of breathing really.
And they're the sort of areas of the, the respiratory system. If there's a problem with that, then it has to be one of those, one of those five areas. With a couple of other bits as well that we'll talk about.
And what we'll do with the rest of this talk and, and the next one coming up is, to say about, well, how do we try and identify a patient is having a problem in one of those specific areas. And once we can, then we know exactly what we need to do to get them a bit more stable. Something not to forget at this point in time is that we can also see patients with respiratory signs and respiratory abnormalities, because they have abdominal distention, because there's, there's something in the abdomen that is taking up space.
It shouldn't be there, classic example, GDB here, and that's basically causing that diaphragm to move forward, squishing the lungs and impairing their gas exchange. So, As well in these patients, we're, we're focusing a lot of our attention on the respiratory system, but making sure we're not missing something obvious in the abdomen that would require specific stabilisation in a, in a different way, such as decompression or draining of any ascites, etc. We've so far talked about our suspicions for respiratory compromise in the respiratory system, but I think we're probably, we've all seen patients who have respiratory abnormalities because of conditions that aren't directly affecting the respiratory system.
So maybe the patient presenting with, with anaemia used to kicknick because it's, they're just compensating, trying to get more oxygen in. Maybe the patient with the heme abdomen again presenting similarly. And, at this point, I, I think it's worth saying some of the, the absolute worst respiratory distress I've seen in cats has been in those presenting with a human abdomen.
And that takes a bit of kind of getting to with your, your approach because it takes a, a brave person to start bluing, a, a cat with respiratory distress with a lot of fluids. But Being aware that these lookalikes can be, can be really quite severe as well for if they're trying to compensate for a problem. But also we know if we're fearful, painful, and that can cause respiratory changes, animals on steroids or have just received opioids typically are a bit panty.
Hyperthyroid cats, of course, they, they do their own thing and, and various other things as, as listed here. So when we're approaching these patients just thinking about, is it definitely respiratory? Could it be one of these lookalikes and contributing or being in charge of the whole thing?
So just thinking outside the box a little bit can be helpful too. But back to those sort of initial actual areas of the respiratory system that can be abnormal, so we said our upper airways, lower airways, plural space, etc. Is listed here.
What we really want to do if we're using this approach is to put together the information we get from that, that initial patient assessment that has been really pretty hands off and try to, try and categorise the patients as being in one of these different localizations. And then once we do, we'll talk in the next session about what specifically we do to stabilise them for that. A lot of this stuff again, we will know, but it's maybe about having the presence of mind it faced with a respiratory emergency to, to sort of think about it this clearly and as I say, this is something that, that really helped me kind of put the pieces of the puzzle together a little bit more.
So, for example, if we got a patient with upper airway disease, so think of your, your favourite most recent BA case, for example, we know that they come with inspiratory effort, they'll have additional stridor noises, upper airway noise when we escult them. And those things are very classic, very localising to say upper airway, and then we can go ahead and sort of stabilise for general upper airway conditions. Other examples, plural space disease, traditionally they've, they've been, we've always kind of taught that they will have a, a, a rapid shallow breathing pattern because they, you know, they don't have enough space for the lungs to expand.
And that's, that's true in part. That's definitely something to look out for, but probably a more specific things for, for them is, That they'll have quiet lung sounds and auscultation, that's actually more of a specific thing for plural space disease. So again, knowing what's normal, knowing what you'd expect for a patient typically breathing like that, and again, finding out the clues to be able to, to categorise the patients in these different categories.
So we'll talk about this, in more detail in the next talk as well. The thing with these patients as well is that there's always clues. It's about trying to be a detective, especially if we can't really do a whole lot of diagnostics at this, this point with these patients anyway.
So thinking about common things are common for a reason, and just thinking what, what's likely to be going on. So is there a history of trauma, in which, so, I'm thinking about primary contusions like we can see in this, this poor dog here, or pneumothorax or, or various other things is listed. Is there a history that maybe suggests that there is an upper airway problem around, so, a history of, of noise, noisy breathing, a change in bark, any of those sorts of things, reported by, by owners as well might, might just kind of shortcut and bring them, bring an end to the sort of the, the medical mystery otherwise.
Similarly, maybe a little bit more unusually, any evidence that's consistent with the so-called non-cardiogenic or neurogenic pulmonary edoema. So that's where we can get sort of flash flooding of the, the lung, more so the, the cor the dorsal lung lobes if we have patients who have made poor life choices such as the chew electric wires as this cat has, we can see the sort of the, the lesions on the side of the tongue here quite telling that that's something that's happened. Or is there a history of prolonged seizure activity, puppies sort of choking, trying to sort of, you know, inhale their food and literally, literally doing that or sort of pulling on the lead, getting caught, and those sorts of things.
So his history, histories that fit with that which would sort of lead us more towards that as an underlying cause. But again, common things are indeed very common and, and patients presenting with respiratory distress after a history of vomiting or regurgitation in my book have aspiration pneumonia and sort of until proven otherwise. This is your sort of typical and beautiful cranial ventral alveolar disease that we can see here.
So again, those are sort of really common things just to have on our radars. And then sadly, many of us will have dealt with a cat like this. And this, this is just a good reminder to say that Dic cats are just the worst.
If you want to give me 10 Dic dogs and a dissonic cat, I'll take the 10 dogs any day. And the reason for that is that cats have really, really little reserve once they present with respiratory distress. They've been hiding it.
They've been holding on to all sorts of stuff. And once they come in, it's because they're, they're really pretty close to, to the end. So they require even more careful handling than dogs.
What you might get away with with a Date dog, you definitely won't with a cat. And as such, I have a really, I do that's a really healthy respect for these Date cats. I went to as a, as a new graduate, I went to a really good CPD session on, on respiratory distress in cats and the, the guy giving it asked everybody to put their hands up if they'd had a dis cat die.
And pretty much most people put their hands up. And then he asked them how many of you had a distant cat die when you haven't been touching it. And that was a very different question with a very different number of hands that were up.
And I think that's true in my case as well. It's rare that they'll die when they're left alone. It's usually when we're doing something to them that that causes their condition to worsen.
And so this careful handling is, is super important. Cats with respiratory distress, we talked about the sort of partial changes at the start of this talk, but it's important to bear in mind that really, if we think about a normal cat's breathing, there's hardly anything to see. And so if there's any increase whatsoever in respiratory excursion, that's really abnormal and a cause for concern again, much more so than in a dog.
And in terms of what's common for them, then thinking about things like asthma, pulmonary edoema from heart failure like this poor cat here had or pleural effusion or all things just have at the forefront of our minds to say, could it be this? Can we, can we treat? Is there evidence?
What are we gonna do with that? So definitely challenging. And there was an interesting study published in JSAP last year that I wanted to sort of mention as we're finishing up this, this first session.
That I thought was, it, it's a really, I was really pleased to see this study because it was a study looking at dismic cats, but notably presenting to first opinion practise. And ultimately, that's what we want to know. And we want to know what happens to these cats kind of right from the start.
We don't want to know once they've been filtered based on who can be referred, who's stable enough to be referred to all of those sorts of things. What happens at the start? And so this was a prospective study again, beautiful to see 108 cats, like a decent number.
And they were looking at physical exam findings these cats. So again, beautiful things that we can kind of do right from the start with them. And they had they been roll cats over a five-year period, and they caught a number of different underlying causes.
So predominantly cardiac, so sort of 65% here, but also getting respiratory neoplastic and traumatic cases in there as well. So quite a sort of broad spectrum to, to say can we differentiate between these, these causes. And what they did was they basically divided these cats into those that ultimately we found to have cardiac dyspnea and non-cariac dyspnea for their sort of data evaluation to sort of tease out physical exam findings to say cardiac or not, which is really one of the most useful questions.
And they found some really quite interesting stuff in my mind. So they found in, cats that had confirmed cardiac dyspnea, and 25% of them had a history of a cough. And certainly that was interesting for me because historically, we've always thought about coughing dyspneic cats having asthma.
Well, a quarter of cats in this study with confirmed cardiac dyspnea had a cough as well. So, something to say, maybe not as specific as we, as we once thought. And if a coughing cat, we should be sort of thinking heart as well.
And what they also did was they looked at findings to say, well, what physical exam findings are useful to predict cardiac associated dyspnea. And interesting, they found that the things is listed in the, the bottom bullet point here were all useful useful markers, so gallop rhythm, hypothermia, tachycardia, and tipney were all useful. And what was interesting there is that the the presence of a heart murmur was not not a useful predictor, so you could have cardiac dyspne without having a heart murmur.
A gallop was was such. And so those are all things again to sort of put together to say, well, could, could it be cardiac is there any strength or the suspicion for that in these patients? The other thing that they did in this study, which again, I thought was a really interesting thing to do, was to, they came up with a triage algorithm based on physical exam findings to try and figure out if you were likely cardiac and therefore, should you be getting diuretic therapy or were you something else and therefore you needed to think a bit more or might need some additional diagnostics.
And so it's a combination of these TPR findings and the presence or absence of the Gallup rhythm that that helps sort of make this, this algorithm. And so you basically start at the top, and then you'd come to a decision-making point, decide yes or no, and it would take you off down the, the various branches. And so this study was actually quite interesting because the, the first point, on this triage algorithm was, is the rectal temperature greater than 40 degrees?
And basically, that was a really good rule out to say if your temperature is over 40, it's not cardiac. And of the three cases that, that met that criteria, they were all true negative. So sort of TN stands for here and they all had something else.
So it seems like that's a good, sort of distinguisher. They then subsequently, if you answered no to that question, you went down the route, around here, you'd look at then at the Gallup rhythm, or then you'd look at the other findings and then you sort of branch off from there. With some true positives, but also some, false positives and so on as we went along there.
So seems like that sort of initial question is, is quite a, a useful distinguishing one. But if you aren't pyrexic, then, it could be a number of things as well. So, Interesting thing, it's not something that I've traditionally necessarily done is checking temperatures in these cats unless they felt markedly abnormal and can tolerate that, but a sort of free information available if it is tolerated that potentially could be a sort of useful thing to think about.
And then the sort of final thing to say in this session is regardless of all of this stuff, it's nice if we can think about most likely causes and all of this kind of stuff, but again, it's, it's all about treating the treatable. And so coming back to making sure that we're not getting carried away with thinking about the what ifs, what could it be that we're still starting with giving oxygen and minimising stress as we talked about. But thinking about things that especially in these, these extra challenging cats, and we were saying about common, sort of the most common causes of respiratory distress being either congestive heart failure, causing palm edoema, and causes of pleural effusion or asthma.
And so thinking about do we just give those therapies up front and say if it's treats are treatable, if it doesn't respond to those, then we know we've got a problem. I'm thinking about sort of early thoracentesis in case of pleural effusion is is part of the deal. And if it doesn't, if none of those things work, then I'm, I know I need to be worried.
I know I'm in for a tougher time trying to figure out what's going on with these patients and getting them better. So regardless of of everything you said, this is probably what it boils down to. And in the next session we'll sort of talk about extra strategies to try and give us a bit more confidence as to what could be going on so.
Hopefully that's sort of a useful introduction to this topic, and we finished it at this point, so I'm happy to. Yeah, we, we actually did finish at an amazing point there, Lindsey, because your sound has just gone all funny. It was absolutely perfect up until the last 45 or 60 seconds.
I'm not sure if your microphone has moved or if your plugin or something has changed on that. But yeah, we've got a lot of electrical interference coming through. OK.
No, that's no better. We probably going to need to Ask you to call in. If you can maybe in the break, unplug your microphone and plug it back in, and see if that makes a difference.