OK, good evening everyone and welcome to tonight's webinar with Carl Bradbrook. Tonight, Carl will be speaking about anaesthesia for the brachycephalic. Pale graduated from the University of Liverpool in 2002, and after a few years in mixed practise, he undertook a residency in anaesthesia and intensive care at the Royal Veterinary College.

He has worked in both private and universally university specialist. Centre, sorry. Carl is a Royal College recognised specialist and a European veterinary specialist and is currently president of the Association of Veterinary An anaesthetists.

Carl joined Anderson Moore's veterinary specialists in October 2018. So we'll set up, we'll kick off with this, presentation in 2 seconds. If anyone has any questions, please just add them to the question and answer box, and we'll get to them at the end.

OK, thank you. Kate Carl, if you want to, you can start. Thank you very much.

Thank you for introduction there. And, good evening, everyone. So, as, mentioned there, we're going to discuss this evening some kind of ideas, some concepts, and some new, perhaps things you've not come across before, when considering the brachycephalic, patient.

And I'm sure we would all, agree that very much these are patients that we're seeing on a much more regular basis now. They represent a significant part of my practise. We see a number of these breeds for both their airways and for multiple other problems, but their airways and the gastrointestinal disease seem to be things that we have to deal with regardless of of their presentation.

For those of you that might want to find some more information and perhaps a review of the current literature, this is a really nice review from two colleagues from Davey's vet specialists, and that was in JSAP at the end of last year. And that provides some concepts and some ideas and maybe the future as well as to where we might go with these patients. What are we going to think about during this session?

Just some considerations really. So some considerations for the patient, the procedure, I'm thinking about staffing and equipment as well within the hospital. And really to focus on the, examination and and preparation so that pre anaesthetic components, and I think that's a really important time for any anaesthetic, but particularly for these patients, how we can preempt what might be an issue for us during the procedure, and during the recovery phase and the induction phase.

Those are all really those two critical phases that we're going to discuss. And how being prepared, allows us to minimise the complications that we may come across and allows us to intervene and, to deal with any issues as they happen. Just going to show you this, just a very short video here, and I think we'll certainly see this with a number of our brachycephalic patients, so kind of a geriatric ug here.

And you can see very much how they can tolerate that endotracheal tube until they are pretty much ready to walk off the table. I've certainly had, patients in the past, particularly pugs where actually they're very happy to walk around. In the prep area with an endotracheal tube in, obviously not just letting them on wander off, but making sure that they are, fully awake, fully conscious and have good control of their upper airway and, those muscles in the laryngeal and pharyngeal area before we extubate and it's a really important aspect that we'll, we'll come across.

So just some considerations really. I'm, I'm really gonna concentrate on on dogs and the kind of three breeds that I'm gonna mention during. And the session that we very commonly see.

So the, the French bulldog, the pug, and the English bulldog. And I think we'd all agree that the French bulldog is really, probably the most represented of those three breeds. The English bulldog we've seen less appears of those, and we see French bulldogs and pugs presenting, both for airway surgery, but also for things like spinal disease, orthopaedic disease, and other procedures as well.

In terms of most of the, in fact, all of the concepts we're going to discuss would apply to cats as well, and it may be that we're seeing some of those more brachycephalic cats, but they don't tend to present with airway disease to us and the majority of times, we may be dealing with them, in terms of their other presenting signs and having to manage their airway as well. So all of the concepts we're going to talk about will also have time with those breeds, with those cat breeds. What are we what are we concerned about, for patients with brachycephalic obstructive airway syndrome, we are worried about the upper airway and that obstruction of the upper airway, and that's in the majority of these breeds, the main area we're going to be concerned about is in the nasopharynx and in the larynx, and they may also have some tracheal disease as well, which may be something that we're concerned about.

We put on top of that anaesthesia, so we give all of our anaesthetic related drugs, all of those components that we require for anaesthesia, and they cause muscle relaxation. So on top of that animal's already present airway disease. We then worsen the situation because we relax all of that muscle, all of that tissue within the upper part of the airway, so the pharynx and the nasal passages, and that means then that we've got a patient that not only has their own disease, we then worsen it with the drugs that we need to use to facilitate anaesthesia.

And that ties in just with what I was mentioning earlier, in terms of making sure that our patient. Can fully protect their airway before we remove that endotracheal tube. What else do we worry about, gastrointestinal disease, particularly gastroesophageal disease.

These patients may present with something like a hiatal hernia, and that means they may already be regurgitating gastric contents into the oesophagus on a regular basis. They may have esophagitis as a component of that as well. And they're often quite stressed, dogs, maybe because of, their temperament, but maybe also because of their difficulty.

With their respiratory system, with the fact that they, struggle to breathe normally unless their mouth breathing as well. So those two components linked together and gastroesophageal regurgitation is a significant problem in these breeds for us during anaesthesia. And if they regurgitate and aspirate that gastric contents, then we may end up with a very severe aspiration pneumonia as well, as well as other sequelae such as esophagitis, and esophageal stricture.

So there's are really important things to consider. Temperature monitoring as well, making sure that these patients are not too cold, but equally they don't get too hot during anaesthesia and particularly into the recovery period, really important to continue to monitor their temperature. Just to mention the components of boas, so there's brachycephalic components that we deal with.

This is very much a dynamic upper airway obstruction. It changes dependent on different factors. The main factor that we're going to think about during anaesthesia is our muscle relaxation that we require from an anaesthetic perspective, but also may make these animals have further significant problems associated with that.

We're very aware that the components of this disease process, this long, soft palates, most of our brachycephalics will have a long soft palate, even if they don't have significantly clinical airway disease. They're synotic area, an issue there as soon as they close their mouth and not getting very good air flow through the nasal cavity.larged tonsils in itself may just reduce the capacity within that upper part of the airway.

They're reverted saccules within the larynx itself, and they may also present with tracheal collapse, which provides us with a significant extra problem in these dogs. Just a little bit of thought about the procedure itself as well. I think really important we think about how we're going to position these patients during anaesthesia.

If we're doing something where we're involved with the head or perhaps with the eyes, then, we might end up with the patient with a very flexed neck position. This is likely to lead to edoema within the upper airway because that compression of the neck, compression of the venous return and compression of the jugular veins within the neck itself. So that's something just to be aware of if the patient is positioned in this in the, in theatre like this for a longer period of time than you might do normally, just to be aware that they may get further nasal edoema, further edoema within the pharynx as well, and that may compromise recovery further.

In dorsal recumbency, we tend to see patients getting nasal edoema. I'm sure we'll all have seen those patients that then they get that nasal edoema fluid dripping from their nose once we extubate and we start to recover them. And that essentially is as that edoema starts to resolve, that fluid tends to leak out and through the area.

So that can be a significant additional problem for these patients. So be aware of that and we'll talk later on about how we can perhaps manage nasal edoema and certainly. That component of of an additional problem for us.

These breeds also tend to suffer from drying of the cornea. They often have quite exophthalmus and positioned eyes, and they tend to have large eyes as well. And that can be a significant problem, so being aware of that in terms of positioning.

And also, identifying with these breeds that they often present overweight, and we position them in dorsal recumbency for a number of procedures that they require and we reduce their ventilatory capacity as well. So they start to hypoventilate. We may see that with some of the monitoring equipment we'll talk about later.

But that in itself then tends to cause collapse of areas of lung, and that's going to compromise the patient further in that initial component of recovery. We discontinue our anaesthetic, we discontinue delivering higher inspired oxygen fractions, and then we expect the patient to breathe spontaneously on room air, but they may have areas of lung capacity. They've already got reduced capacity anyway.

And they tend to have lower lung volumes, and then we have issues with patients not being able to saturate in that initial recovery period. So really important to think about that if they're positioned in dorsal recumbency. Some essential bits of equipment, for me in terms of how I will think about managing these cases I think really important to have very good IV access, talk about when we should be thinking about utilising and gaining IV access.

Don't be afraid to use a sedation appropriately, and actually, I like to sedate these patients earlier on. Not talking here about having to have them, to be kind of flat, but we want them to be calm. We don't want them to getting hot.

We don't want them to be panting excessively, getting airway edoema before we even think about any procedure with them. They may require oxygen in these early stages. And I'd like to have an example I'll show the next few slides, an airway box with equipment in one place.

We don't want to have to be going to several places in the clinic to collect components if we start to have a more emergency situations having an airway box ready. Having something is shown on the slide here, a regurge box, a suction box, where we can, we can access those components all in one area and very difficult I find to come across you in our clinic, but a calm environment, a calm place to think about starting to anaesthetize these cases. In terms of components for an airway kit, great to have it in some of box like this, very obvious what this is.

Restock after every time we've used it. Things like a laryngoscope, some stylets. I like to have some, dog urinary cats available.

They're very useful for getting into the airway if we can't pass an endotracheal tube easily, and then getting a tube over the top of that, or at least delivering oxygen while we decide what we're going to do next. Active and considering to have some other airway devices, maybe things like tracheostomy tubes, laryngeal mask airways, and other components that cannulas if we need to perform an emergency tracheostomy. So everything is available.

We haven't got to go looking for it elsewhere in the clinic. So the dog human cast is really useful. Some maybe an induction agent in here and some syringes and needles, so we can very quickly and get those components and several sizes of endotracheal tubes.

These breeds tend to require much smaller endotracheal tubes and we would like them to have a certainly much smaller than an equivalent sort of longnose breed of the same body weight. What's important when we think about our pre-anesthetic assessment, in these brachy breeds, really the exercise ability for me is an essential component and certainly from our clinicians, this is something that They're very good at bringing that information back to us, and this gives us a really good idea about how these animals normally cope. Can they exercise at all?

Can they exercise for half an hour, 5 minutes? It's going to give us a good idea about how well they can cope when they're perhaps a little bit stressed as well, around the whole of that perhaps induction recovery period. What's their respiratory effort and noise like?

Does the owner think that they already have evidence of regurgitation? Maybe they do that silent regurgitation where they that lip smacking, they swallow, but they don't actually produce any material out of their mouth. Maybe they do actually regurgitate and the owner noticing them do that, when they're either in, when they're eating or when they're exercising, really useful thing to have as an additional bit of information.

Previous anaesthetics. Great to have an idea about perhaps what size in the tracheal tube that patient required previously. Did you have any problems?

Did that patient regurgitate during anaesthesia? Did they have a horrible recovery where we had to manage in a different way, and really useful to have an idea about how well they responded to the drugs that we used previously. Did they sedate well with the premedication we used?

What was induction like? Very, very important bits of information. And obviously making sure that owners are very much aware of the complications, even if they're not patients presenting for airway surgery, the owners are aware that the airway is a significant issue for us, and maybe a problem making sure owners are primed for the airway to be an issue in these cases.

Any other comorbidities, particularly here thinking about gastrointestinal disease, maybe previous ocular sort of corneal ulceration disease as well. And an awareness of what the procedure, is it a surgical procedure, what analgesia we're going to think about? Is it a diagnostic procedure as well?

Useful to have that in the back of our mind. Standard clinical examination, most interested in cardiac and thoracic auscultation. I mentioned already these, patients are often, obese, and I think an idea of their body weight and their body condition score can be useful, temperament.

Although most of them are generally, quite amenable to things that we like to do, they do get stressed, that can change their temperament within the clinic. And that may change how I manage these patients, particularly in with regard to IM, IV placement, IV premedication, what we're going to do with them in the recovery period. And something that's coming through from the work, the very good work that's being, performed, at Cambridge University, the, the brachycephalic Research group there, thinking about exercise tolerance, and they're now started to produce, people that are able to, to perform as assessors in terms of excellent size tolerance testing and actually grading these patients and deciding if they have clinically.

Significant, boass that may require surgical intervention and giving them a grade that we're able to think about how we're going to manage these cases. It's a really a great area of further research and an area I think that'll become very useful in the future. But thinking about kind of considerations, thinking about the ASA status of the patient.

So can we grade that patient on the scale, so 1 through to 51 being a completely healthy patient, which these brackets are very unlikely to be, 3 to 5 being a patient that requires immediate intervention is unlikely to survive for the next 24 hours without, an anaesthetic and some sort of surgical procedure. So useful to think about that, useful to guide the whole team in the clinic about how we're going to deal with that case. Patient factors, and specifically then the disease and process factors as well.

So what are we actually dealing with on top of the fact that the patient is brachycephalic? In terms of preparation, then the safety checklists, which I'll mention over the next couple of slides, a really, really useful way to focus at induction of anaesthesia, so that everyone is aware of what we're anticipating may be problems during the procedure. There's an example here just on the slide of the, the checklist that's available from the anaesthesia Association website as well.

Thinking about equipment, and, and personnel. As well that we might want to have, making sure that we're prepared before we induce anaesthesia. So we'll do a a little a question poll here just to get an idea about OK, so I am going to launch the poll.

So the question for the poll is, who is currently using the safety checklist for all anaesthetics at the clinic? So I'll just launch that. So, OK, so the results are, there's 26% are actually are actually using a safety checklist and 74% are not using a checklist.

OK, thanks, Caroline, you're really interesting. Numbers there, and I'll just, just kind of briefly over this next slide, just kind of show the checklist and give people an idea about why I think we've already talked about why this is, in my mind, a very useful concept, and this is something that we utilise on every case that comes through, requiring an anaesthetic, and also now we utilise a different version for patients requiring sedation as well. Really quick to do.

This is the two sides of the checklist. So on the front, we have the safety checklist itself and on the, on the back of it, some recommended procedures as well in terms of other things to think about during the anaesthetic. They're very easy to adapt and to change for your own clinic so that they utilise everything that you require and that people engage and utilise them as well.

And it just allows us to focus, particularly with these kind of more difficult cases where we're likely to come across complications. So really useful focus here for the whole team. So the pre-induction one, before induction of anaesthesia.

The second one. Sorry about that. The second one before the procedure itself, so a time out.

Are we happy with the patient at this point? Any concerns from both the surgeon and the person monitoring anaesthesia, and then a final one at the recovery period with a plan for how that patient's going to be maintained and monitored into the recovery period as well. So really useful, as I mentioned, this version, which you can download from the AVA website.

And very easily adapt this to to your own clinics, how it works. So moving on really just to think about anesthe the anaesthetic period itself, what are we, you know, when are our periods of of most concern, and I think really the recovery period is one we're gonna focus on for a considerable amount for the rest of the session. But thinking about how we're gonna manage the patient before anaesthesia, induction and intubation, really important times as well.

At one point, we're gonna have, we're going to be inducing anaesthesia, inducing unconsciousness. We have to secure that airway. The patient obviously can't maintain their own airway at that point.

And then later on in the procedure, we're going to have to extubate, we're gonna have to remove that more patent airway, and our patient's going to have to be able to maintain their own airway. So a really important time. As well, and I think that's probably one of the biggest risk periods for us to see.

In terms of any pre-operative assessment and sort of pre-operative diagnostics that may want to perform blood work, obviously dependent on the patient and the patients presenting clinical signs, and maybe some diagnostics as well. And I find it very useful unless it's in more of an urgent situation or able to manage these things on the day. If we can have these things performed prior to the day of anaesthesia.

It causes less delays on the day of the anaesthetic itself. And also we're very much aware already of what we're dealing with. We can, we can discuss with the clients our concerns, and we're not dealing with something where we may actually go, we've got to delay things on the day now, so useful to get these things, out of the way if possible.

In terms of preparation then for anaesthesia, we've discussed already whether we may require some sedation. I find Ela cream really useful in this case, we often clip the both cephalics prior and just when the patient arrives, maybe at the time we give an IM sedation IM cream medication if required, use Ela cream on the skin so that they are more accepting for IV placement, really useful to get IV access early if possible. And we'll talk as well about what options we have now and what we consider using for prophylactic gastrointestinal protection.

I mentioned particularly focusing on the fact that these patients often have quite significant gastrointestinal disease as well, making sure that we've got our air equipment, ready. So I mention at this point about some fasting periods before anaesthesia and our concern regarding how long we should fast a patient for and the risk associated with regurgitation. We don't have any specific studies out there at the moment looking at brachycephalics, as a particular, breed, so focusing on those in, as a single kind of entity breed.

But we do have a number of studies out there now looking at the effect of how long we fast patients for on the risk of reflux and regurgitation. This study, which was one of the most recent ones that was performed, was on healthy dogs. So again, it's not our kind of brachycephalics with other clinical diseases that are evident.

So healthy dogs undergoing elective orthopaedic seizure. Interesting, the risk factors that came out of this, so we either had an 18 hour fast or a 3 hour fast with the dog's normal food that they ate, at home. So age, as age increased and increased risk associated with regurgitation, the patient being in dorsal recumbency.

The duration of anaesthesia and also the degree of fasting, the length of fasting as well. So actually, if the patient was fasted for 3 hours, then they had an increased risk of gastroesophageal regurgitation in this case, in this study, sorry, and those dogs that were fasted for that longer period of time. So essentially an overnight fast, so somewhere between 12 and 18 hours had a reduced risk of regurgitation.

I think reviewing the rest of the literature that we have available at the moment, then, our focus should probably really be that we should be having fasting periods, a minimum of, sort of 8, probably 8 hours. We shouldn't be dropping much below sort of 6 hours unless I required, and probably most clinics are starving or fasting patients between about 12 and 6 hours. I think with a much less than that, we have to take into consideration that increased risk.

Associated with a risk of regurgitation, but also the risk that the gastric contents is increased, talking about a patient that's already got a reduced ventilatory capacity and then we have a large stomach as well. So something else to consider in terms of the risk of, of reduction in in ventilation. So we'll just do our second poll, at this time just to get an idea about how long people are fasting patients for.

OK, so I'll launch this poll. So the question is, how long do you stop an adult patient prior to anaesthesia? Is it 4 hours, 8 hours overnight, or 18 hours?

And that pole should be launched. OK, thank you. So the results of that poll are that 93% of people are fasting overnight, 3% are fasting for 8 hours, 3% are also fasting for 4 hours, and no one is fasting for 18 hours.

OK, really interesting. I think that that kind of ties in what we just discussed then on that, from that study that's out there. A few people, interesting just a few people that fasting for that very short period of time, which we tend to now.

I tend to not use unless it's more of an emergency urgent procedure where we cannot afford to fast patients for longer periods of time. Obviously different if we're thinking about paediatric patients here, where we are likely to be starving, fasting for shorter periods, but that overnight fast, would be the kind of, the mainstay of our procedure now. Move on to thinking about premedication, interestingly, out of the work from Cambridge, as well as looking at these lung volumes, looking at these grading of our brachycephalics, and some of the side work that's come out of this is, is whether certain breeds respond better to premedication with, certain, drugs that we have available to us.

And it seems that maybe the pugs, sedate better with alpha2 based protocols, and they also don't seem to become hypertensive with these, and the French bulldogs seem to sedate better with aromazine-based pre meds. Very much related to breed and but maybe some temperament related components here as well. Obviously, if you're dealing with a patient that's very stressed, maybe.

Is aggressive or is nervous, then just giving ACE proromazine or just using an alphat may not always be, sufficient in those cases. So an interesting, interesting kind of side part to the work that they're doing. Obviously important to think about the sedation component, but also analgesia, if this is a surgical procedure, very likely to be adding an opioid, a mu opioid in, or if it's a, a diagnostic procedure, we may not require that new opioid component.

Our options, in terms of analgesia then methadone or buprenorphine, and our sedation drugs, thinking about things like aromazine, meatomidine or dexametomidine, depending on which of those drugs you're using in the clinic, which you're familiar with and which you feel most safe at using. And we can be giving these drugs IM if that's required, if we require that sedation, perhaps before IV placement. In that particular patient, or we can be utilising them down at the lower ends of these dose ranges and perhaps considering giving those IV after we've got IV access.

And that way we're able to be with the patient during pre-medication and monitor them very closely at this time. For gastrointestinal protection now, we are utilising omeprazole as a routine for these brachycephalic cases regardless of the procedure they come into the hospital for. Two options here, we can consider giving it orally and there's a nice study from a few years ago, which looked at getting 1 milligramme per kilo of omeprazole orally 4 hours before anaesthesia and showed that that's .

Improved pH or increased pH didn't necessarily reduce the risk of regurgitation, but it reduced the risk of getting sequela from the patient actually regurgitating, to reduce the risk of getting onset of esophagitis, esophageal stricture does need to be required, does require to be given several hours for anaesthesia, that can be a difficult component sometimes. We, where possible, tend to utilise it IV and we really want to get this on before, before induction of anaesthesia where possible. So the same dose, 1 milligramme per kilo, give that IV before induction.

If the patient has, an episode of regurgitation, then we generally consider that. We continue that for 5 days post anaesthesia, but in the majority of these brachycephalics now, just because they tend to be hospitalised for a period of time, maybe that adds to their level of stress, then we do tend to, continue, for further 5 days as well at 1 milligramme per kilo daily. Something else to consider in terms of, of kind of prokinetic treatment.

And we, I think I noticed more and more when we're actually doing, imaging studies with our brachycephalics, they don't have normal gastric emptying times. Maybe they've been starved, as we discussed, maybe they're in the hospital, they're stressed, they're outside of their normal environment. That changes their gastric emptying time.

And we've noticed more and more, but that maybe this adds to some of our ventilation issues, but also may add to the risk of either regurgitation or other gastrointestinal complications. So very routinely, very commonly used metacholic forms an IV infusion then. Couple of questions to think about here.

Should we be using with all our brachycephalics? It seems from talking to my soft tissue colleagues that they, they think that the pug breed, the pugs tend to have less significant gastrointestinal disease than the French bulldogs. So we tend to use it routinely with French bulldogs and English bulldogs.

And if we have a pug, and it has known gastrointestinal disease, and we also use metoclopramide in those breeds as well. So the other thing that we noticed and nothing necessarily published in the literature about this yet, is often these are pros look nauseous with opioid administration post anaesthesia, and metoclopramide seems to see something that helps with that as well. So it can be consideration that after perhaps methadone administration, they look nauseous for a period of time.

And we find that that may improve the metoclopramide. Meroposin could be something else to consider at this time as well. Vascular access, really, really an essential component here for before induction of anaesthesia, really useful for any emergency interventions, emergency drug requirements as well.

I find the the lateral saphenous vein very useful in these breeds. Of particularly with pugs, they don't like you touching their front feet, they don't like you pulling to extend the forelimb to access the cephalic vein, and certainly with some of those other French bulldogs as well. So the lateral safness, this vein can be accessed in with the patient in lateraly, but also with the patient standing.

Tend to find you don't have to touch their foot quite so much, and they often are much more comfortable with getting hind limb access than they are with us utilising their front legs. Make sure, that we've got really secured IV access, really important. We don't want these, we want to lose this, particularly around induction or in the recovery period, so, good, good secure, good taping of, of our IV access.

Any additional access points that we might require, I tend to utilise and get these post anaesthesia, post induction, sorry, so that we don't stress the patient by trying to place perhaps multiple IVs before induction of anaesthesia. Our IV induction phase is going to be given to effect. The agents you choose should be the one that you're comfortable with, the one that you feel most safe utilising.

These are not cases to try a new agent if you're not familiar with how to utilise that agent. So the most important thing I find is that we give, our agent slowly to effect, to facilitate intubation. I find it essential now to use a scope, I'm, I can't really intubate without a laryngoscope.

The illumination and the access that it gives us by displacing the most dorsal aspect of the base of the tongue which I find it really useful in these cases. Assess the tracheal diameter and look at lilac, or look at laryngeal function, assess the airway, so I've got an idea at this point how that patient may recover from anaesthesia and whether we're going to have to intervene at that point. And it's also really useful to know at this time what the size of our endotracheal tube is going to be for maintenance and recovery as well.

If I've got a, you know, 8 kg pug and we can only place a 4 millimetre ET tube, that patient's going to be a concern for me in recovery. But if we place maybe a 6 or a 6.5 tube, we're likely to have a much more smooth and a less recovery, less requiring us to be so vigilant in terms of having to be aware for perhaps for reintubation.

Important to make sure that the patient is at a sufficient depth of anaesthesia. If they're light for intubation, that increases the risk of regurgitation, because they happen to swallow, and also it increases the risk of us actually causing trauma, maybe causing edoema then within the larynx as well. So really important to have the patient that sufficient depth.

I like to make sure they're internal recumbency with a slight elevation of the head. Measure the endotracheal tube if possible and cut the tube so the tube's not going to extend further than the thoracic inlet. I like to make sure that intubate the chir, we check the position of the tube, we check to see if we need to inflate the cuff and before we allow the head to drop.

So if that patient then regurgitates, we've already got a secure airway, we're not going to end up with the patient regurgitating, and then that material being able to go down the trachea and be aspirated into the lung. Just look at a short video here of how we might manage one of these cases, a little French bulldog here. So we've got IV access and we've given our pre-medication at this point.

We're just doing the safety checklist. You can see one of my colleagues there at the back of the video, and measuring off on ticking off, sorry, on the safety checklist. So we've given IV premedication, we're pre-oxygenating already a really useful thing to think about doing in these cases.

To ensure that we've got time if intubation is difficult. Something just to allow us so that our fingers are not in the way, during intubation and we get good visualisation of the larynx. Give me a little bit more induction agent here because we're still not happy that the patient is at a sufficient depth of anaesthesia.

And you can see we've got our laryngoscope with illumination with light available to us, at that point. So really useful to have that. It allows us, as you can see here, to, displace the tongue, able to pull the tongue fully out.

So don't be afraid to move the tongue out. A nice head position there, got really nice light, really nice illumination. And of the airway, administer our oxygen there as required.

You can see we've got good visualisation. We can see the larynx at this time, just assessing the airway, looking for those components we talked about in terms of the boast and disease process itself, and making sure that they we're aware of any complications we may see in the recovery period. And then finally, after we've done those components, intubation, at that point, as I said, with an appropriately sized, endotracheal tube.

I mentioned earlier on that nasal edoema is something that we see in in a number of our patients when they're positioned, particularly in dorsal recumbency, with a tube tie placed either around the nose or even around the back of the head behind the ears. And in the brachycephalic breeds, then that positioning may add to nasal edoema, but the likelihood is that they've probably got some aberrant nasal turbinates. They've got edoema of the nasal mucosa that develops during anaesthesia as well.

And that means that these patients, if they have a closed mouth in recovery, they're not able to move air through the nasal cavity, of which in one of the longer nose breeds of dog would be able to do. So a really useful treatment I find here is to add in a nasal decongestant as well. So one of the we use one of the ones that's available that you would use in people.

This provides for vasoconstriction of the nasal mucosa. It's got a very rapid onset, and a very long duration of action as well. And we tend to put around 0.5 mL, into each nostril.

If you're using the drops here, I tend to put 1 or 2 drops into each side of the nay, just have the head slightly elevated and allow that to run down, into the nasal cavity. And it's amazing how that really reduces the amount of edoema in the nasal cavity and allows these patients a little bit more effort so they can actually breathe through the nasal passages if they're not able to fully open their mouth in that initial recovery period. So I tend to use those this after induction of anaesthesia so that we don't develop further edoema during the procedure.

In terms of maintenance of anaesthesia, inhalation anaesthesia is going to offer us really the most kind of benefits we get, where you can rapidly change the depth of anaesthesia, and we do get some bronchodilation as well with our inhalation agents. So whether we're using either sevofluorine or isofluorine, we will get some amva dilation. The negative side of using inhalation anaesthesia is that we get dose dependent, both vasodilation, which can lead to hypertension, and we get respiratory depression, so we get hypoventilation.

So we want to be thinking about can we do any other adjuncts? Can we give other analgesics? Can we do any local anaesthetic techniques if it's a surgical procedure that will allow us to use the lowest vaporizer setting that's possible to minimise these, these risks.

As we've discussed already from an anatomical and a positioning perspective, ventilation is very likely to be a compromised, and these patients may require IPPV either manual, so bag squeezing, or if you have a ventilator available, mechanical ventilation as well. And really I find canography and measuring entoal CO2 a really useful monitoring tool in these cases, we're able to very effectively see how well these patients are ventilating. And we'll also be able to assess if we've got anything that may be either obstructing the endotracheal tube, maybe the positioning of the neck is not adequate as well, you're going to see that with catography.

For those performing airway surgery, this is a very challenging scenario to monitor our patients from, can't obviously we can't see the patient, we can't access the head like we would normally rely on in terms of monitoring of anaesthesia. So we do require some additional monitoring equipment. And I mentioned already about catnography, but pulse oximetry, a really useful tool.

We get an audible beat. We get a pulse style wave form. We know that we've got, we've got blood flow.

We get our SPO2, and we get a pulse rate as well. Blood pressure, useful, for us to see that we're not, too deep, our patient's not too deep. We are adequately volume resuscitated as well.

And I mentioned already about body temperature. We want to make sure that these patients are not too cold, but equally we want to make sure they're not going to be too hot as they go into the recovery period. Positioning for those reasons that we've already discussed, being aware of whether we're going to see collapse, both of the dependent lung, if we're in lateral recumbency or of the dorsal aspects of the lung if that patient's in in dorsal recumbency and how that may affect us in that immediate recovery phase.

Do we need to give supplementary oxygen as the patient starts to breathe on room air, to make sure that we do not get desaturation in that initial period. Recovery really is that very important phase, and we are going to have to remove the endotracheal tube at some point, but we really want to make sure that we assess, if possible, endid or CO2, the patient's able to ventilate. Normally, do we think that the patient's got normal chest excursions so that we can assess, their, their kind of ventilatory component?

Neither of these things unfortunately is going to tell us how our upper respiratory tract muscle function is. And that's where I was mentioning earlier on that the later we can extubate, we need to, we need to excuate safely. We don't want to be patients so light that they're able to chew, they able to bite onto the endotracheal tube.

But if a patient can lift their heads, for a short period of time, this is likely to suggest that they're able to have sufficient muscle function to tolerate no endotracheal tube and maintain their upper airway patency. What other, kind of therapies or the components can we think about into, our recovery phase? I think really important to continue to have some monitoring equipment.

I like to have a pulse oximeter on my patients in that initial recovery period. We know from the SEPSA study, somewhat getting old now from the kind of early 2000s, so looked at a large proportion. Of dogs and cats in that perioperative per anaesthetic period and assessed what was associated with fatality and mortality and morbidity in that in our anaesthetic period, up to 72 hours post anaesthesia.

And roughly between about 40 and 60%, so varying from the dog, about 40% to the cat, 60% of deaths occurred in that immediate recovery period, so within about 4 hours of anaesthesia. So really important to continue to monitor well. Supplement auction, as I mentioned, if necessary, an extra base as late as we possibly can, in those cases, avoiding, the patients getting too stressed, in that recovery period.

I utilise something like either some vet wrap in the mouth or, some, some, some tape. That allows us to open up the mouth. The first thing that that patient starts to become light very quickly, then we're able to have the endotracheal tube so that they're, they're gonna bite down, are gonna tube clamp down onto the tape or the, the vet wrap first, gives us some time, to remove the endotracheal tube.

And once we have extubated, this keeps the mouth open so that the patient can move air through the mouth and they're not just reliant on the nasal passages for, for air flow. So they can, as you can see even in this photo here, the patients become, they're very tolerant of their interotachial tube, and they will allow us to maintain that intacular tube until they're relatively close to being able to sit up and maybe even maintain that sternal, that head lift, before we remove the tube. Monitoring is very useful, so pulse ox symmetry placed on the tongue if they'll tolerate that, or maybe on the lip.

And if you've got a reptal probe, then you can also use a rectal probe as well so that you can have it, distance from, from the head to ensure that we have good, good monitoring. Don't be afraid to use further sedation in the recovery period, so very low doses of IV Aromazine or low doses of which of the other the alpha 2s that you use in the clinics and melatonin or dexmelatoidine, just allows the patient to be less stressed. And maintain perhaps the undertaker achieve for a longer period of time and prevents them from recovering rapidly and getting stressed out, but vocalising and panting excessively, which then tends to make the patient warm, and also increases the risk of them developing airway edoema in this initial recovery period.

Problems that we may anticipate, though by using sedation, excess sedation. So just be careful in terms of dosing, use low doses. You can always give more sedation if it's required.

And obviously if sedation becomes so excessive that we're concerned, if we're using the alpha 2s, then we can antagonise the alpha 2s and remove that sedation as well. Both airway obstruction due to upper respiratory tract muscle and other tissue, perhaps edoema as well. An airway collapse, if you've already identified that the patient has laryngeal collapse, this may be a problem for us in the recovery period.

Important to think about when to send these patients home, how do we want to recover the patient, when do we want to we want to send them home, a couple of hours or so after anaesthesia or do you want to keep them in and hospitalise them?ifficult decisions to do unless it's on an individual case basis, and we vary depending on the surgical procedure itself and the patient's temperament and how stressed and anxious they get in the hospital. Can be really useful to suction the airway and suction the oesophagus perhaps before recovery from anaesthesia just to remove any material, remove any secretions from the endotracheal tube and the airway as well.

If we find that the patients show signs of airway obstruction, and so we're going to see increased respiratory efforts, I find it really useful to try and gently pull the tongue out. As I mentioned, suction of the pharynx, if we need to at this time, don't be afraid to induce anaesthesia, intubate the tea, and then recover the patient a second time. And often this is enough.

To allow the patient to recover more smoothly the second time. There's less inhalation agents present in the, in the patient's system. And I'll talk a little bit in a minute about another component of we can add in at this time, which can allow us perhaps to recover more smoothly if we require to a second, a second time.

If we have a repeated failure to be able to extubate. Think about things like, have we got excess muscle relaxation, can we antagonise any drugs that may be causing that, particularly thinking here about the alpha 2 agonists. Consider whether a tracheotomy might be something to utilise at this point and be consulting with the client as to what they would want to do at this time as well.

Useful treatment I find in these cases where either we have to reintubate and we're trying to recover for a second time, or those patients that have laryngeal collapse or a very small tracheal diameter, or those that have had airway surgeries to nebulize them with adrenaline in that immediate recovery period. We're using adrenaline here to cause vasoconstriction, so again, it reduces the amount of edoema within both the pharynx and the initial part of the, the pharynx and the larynx, and also in the nasal cavity as well. And it also causes bronchodilation.

We nebulize these patients for 10 minutes. Close observation during this time can be repeated after 30 minutes if necessary. Tend to generally do this after extubation, but if we have to reintubate a patient and recover for a second time, then I will nebulize them with adrenaline while we're waiting for them to be extubated for that second period of time to reduce any edoema already within within the nasopharynx.

Just to show here, this is using a commercially available nebulizer where you put, we dilute adrenaline. I'll show you this on the next slide, the the dilutions that that I utilise, I have the head lifted when the patient takes a breath, we want that, we want that nebulized adrenaline to be drawn into, into the mouth, and that way it's gonna have the most the most effect. These patients will start to look a bit pale, start to get pale mucous membranes associated with vasoconstriction.

And, that should not be something to be worried about. We want them to see that we know that it's been effective, if we start to see pale mucus membrane. So it's a very, I find a very useful additional component to use, in the immediate recovery period.

You can repeat it every 3 to 4 hours if required, overnight or if you're hospitalising patients during the day, as well. And. We, I tend to dilute it on a weight basis using the commercially available one make the 1 in 1000 adrenaline solution and diluting with just normal saline.

So to summarise, for this webinar, then really preparation is the key. I hope that you saw that I spent, we spent kind of half of the lecture talking about what things we're going to do before we've even considered anaesthetizing the patients. So being prepared, being aware of what complications we might come across and how we're going to manage those complications means that when they do happen.

And hopefully they're not going to happen, then we're much more able to, to effectively work together as a team to ensure the best outcome for our patients. And certainly as we see more and more of these breeds, and then I think we're going to be dealing with more and more of these situations as well. Making sure that we consider the airway, particularly the upper components of the airway, gastrointestinal disease status of the patient as well.

The procedure itself that we're thinking about performing, really important to think about that, and the patient, the breed, and the species, and also the stress levels, the anxiety associated with that patient and themselves. So how can we minimise each of those components in terms of how we manage those case? So again, the outcome, is what we would like for that patient.

We should be securing the airway early, so intubation is when we get good control of the airway as, as quickly as possible, and we should be extubating as safely and as late, as we possibly can. So really important there and hopefully you can see they do tolerate endotracheal tubes, but just being aware of those patients and making sure that they don't get too, too light and damage the endotracheal tube, at that component, so. A really, really, useful, component there of making sure that we remove that endotracheal tube, as late as, as safely as possible.

So I'll I'll finish at that point with the, with the session and we'll look to see if there are any, any questions at this time. OK, thank you very much, Carl, for that really informative talk that I'm sure that there's plenty for everyone to take back to practise. So we do have some time for some questions, so I'll just wait for some to come through.

OK, so we have one come from already, Carl, so the first one says can we use Mropotin or Cerenia instead of omeprazole along with pre-anesthetics to reduce the risk of regurgitation. That's a really good question, actually. So we, I tend to, we tend to use Meropotent in combination with omeprazole.

There's, there's not any evidence to suggest that Meropotent is actually going to reduce the risk of regurgitation, unfortunately. But what I, what I like about Meropotin, and what I noticed more and more is those patients are particularly nauseous, perhaps because they've had methadone. For example, in the recovery period, then they look nauseous, they tend to salivate.

Meropotent really helps, I find with those cases to reduce that level of nausea and reduce that salivation. So we, so I do use it and I would recommend it in the brachycephalics, but unfortunately, it's not been shown to have a beneficial effect on regurgitation itself. So do tend to pre-treat them as well with .

With omeprazole and we would give Meropotent in, in combination with that. OK, so we have another question. Do you use steroids at all?

We, I, I suppose something from me, I'm, I'm probably, I'm kind of lucky that I leave for the, the surgeons, for the clinicians to decide. So if the, if patients are presenting for airway corrections, so they're having airway surgery. Then we have some surgeons that like to use corticosteroids in those cases, particularly those where they may have laryngeal collapse as well.

They've got tracheal collapse, or they've got significant already airway edoema, then corticosteroids would be used for the other, some of our other surgeons, they're happier to use nonsteroidals in those cases still unless they anticipate a significant. Inflammatory issue post surgery. So we do use them both.

We only tend to use one or one or the other. OK, thank you. And one more, so how do you measure the length of the ET tube before induction?

You've suggested a larger diameter, but wouldn't that, isn't that tube going to be longer? Well, that's a really a really good question actually. And I think it depends on the tube that you're using, so I tend, we tend to measure tubes to the thoracic inlet.

And then I cut them, just in front of the nose, so just at the exit to the mouth. You're, you're right, with a longer tube, then, the only thing that I'm really worried about with the longer tube, with a bigger diameter tube, sorry, is where the, pilot balloon exits. So obviously you've got the tubing from the cuff that goes to the pilot balloon.

And providing that, you can cut the tube obviously after where that occurs, then I still cut those, bigger diameter tubes down. So, I think that's really important that we don't want the tube to go too far, then it ends up maybe going into one of the bronchi and we obviously only then ventilating through one lung at that point. Actually a really important thing just, and the good component I just think about in terms of the size of the endotracheal tube.

We obviously want to place the safest size of ET tube we can, the biggest we can, but being aware that we want the tube to be so big that as you place it, perhaps it starts to almost scratch down the tracheal mucosa. So. A safe size tube.

We've obviously got the cuff there so we can inflate the cuff if required. So don't be too, you know, don't be worried about having to place the biggest tube that really just squashes into, the chir as well. You can use the cuff obviously to place a slightly smaller tube, if you feel more comfortable and you're less likely to damage the mucosa as well.

OK, so that's, that's all for questions. So I just want to thank you again, Carl, for a really informative talk this evening. And thank you to everyone who has attended the webinar this evening, and I hope you have a good rest of the night.

Thank you. Thank you. Bye.