Lovely. Thanks very much, Bruce, for that kind introduction and welcome everybody to this evening's webinar. So we are going to look at options for safe sedation, for dogs and cats, in, in practise.

So just a little bit of an introduction to, to start with and some things that we're gonna kind of explore and focus on during this session. Will be really that kind of question, it's something that comes up on a, I think on a daily basis. Should we be sedating patients or should we be using general anaesthesia.

So hopefully we'll have some pointers during this session on kind of ways to look at these two, these two options. And really what questions should we be asking to decide if sedation is appropriate for a certain case? I'm gonna go through some general principles of sedation, so looking at the way I suppose I think about it in my mind, for the cases that we are presented with where we do use sedation over anaesthesia.

And then really some selection, how we select sedative protocols for our healthy patients where we're not concerned about any disease or any particular compromise, and then looking at those sick or compromised patients where sedation may still be required, perhaps for making a diagnosis or for at least doing some sort of diagnostic testing. To allow us then perhaps to move on to more definitive treatments, but those cases often require sedation, still to allow us perhaps even to perform something like abdominal ultrasound. And we're going to utilise some case examples to focus on both those healthy patients and also those more sick patients.

This is a question I remember this used to come up a lot when I was teaching in university practise and obviously teaching undergraduate students, but what really is the difference between sedation and anaesthesia, and that's something we're going to explore over the next few slides. But I always like to think really that for sedation, the patient should be very calm. They obviously, are accepting perhaps of some non, some non-invasive procedures.

So perhaps blood sampling, some imaging as well. But they should be arousable upon stimulation. And by that, we're talking about repeated stimulation, perhaps loud noises, or direct sort of tactile stimulation.

And that's obviously very different than what we all have in our mind with regards to anaesthesia, where the patient is not rousable. That's something that I always used to use with our students with regard to sedation was actually if you could open the patient's mouth and you would be able to intubate, then really that is a patient that's not sedated. They can't control their airway, they can't protect their own airway, and really anaesthesia is appropriate there.

So, although I'm gonna kind of introduce perhaps kind of like moderate and deep sedation, they're not terms that I, tend to use too much. I think that once we get into the, you know, someone asking for deep sedation, perhaps we should be considering whether anaesthesia, is more appropriate. So what things when we look at to decide whether the sedation or anaesthesia is appropriate.

So the assessment of patient health status. So are we dealing with a patient with that with multiple comorbid disease where we're likely to be able to be limited perhaps since the in some of the drugs that we can utilise to provide sedation. And therefore, we're going to be topping up.

Perhaps the procedure is going to take a significantly longer time, and we're going to end up perhaps with the patient as a perhaps more of a distressed recovery from sedation as well. We might be thinking that anaesthesia is more appropriate in those situations. And I think we've all been in the in those scenarios where we're trying to utilise perhaps small amounts of limited amounts of drugs, and the procedure just seems to take forever and actually we look back and perhaps reflect and think that anaesthesia perhaps would be more appropriate.

Patient signalment, and I think the classic one here, and obviously I think we're all seeing these cases on, on a daily basis now are our brachycephalic. So should we be sedating brachycephalic even for more routine diagnostic imaging, or should we thinking about anaesthesia we've got protected airway? Any previous records that we have, perhaps of either sedation or anaesthesia may allow us to determine whether a protocol we used previously or selected previously was appropriate and whether that patient would required perhaps conversion to anaesthesia and therefore that might be a more appropriate and protocol for, for this time.

What's the stimulation associated with the procedure to be performed? So is it going to be perhaps a relatively noninvasive procedure? So some sort of imaging, and maybe with fine needle aspirates, where sedation is likely to be adequate.

But if we're thinking then about moving on perhaps to performing. Surgical biopsies, or even in some cases, joint taps where the patient may not be, sufficiently analgesed as well as sedated for those procedures. Who have we got to monitor the patients?

Sedation still requires patient monitoring, and often it's more difficult to monitor effectively with a sedated patient, they don't accept the same pieces of monitoring equipment that we might utilise during anaesthesia. So who have we got available to monitor the patient? And then not forgetting really, I think, the importance of what the past experiences of performing this procedure are.

So this is a procedure we perform every day. We used to, we know what to expect from the sedation. We know what to expect from the procedure, then we're much better prepared, in those cases as well.

Just thought I would use this table to demonstrate perhaps some of the differences between kind of levels of sedation and anaesthesia. We may only require perhaps moderate or light sedation to perform something like perhaps chest radiography or abdominal radiography. And equally, that may be adequate for abdominal imaging, but then when we move on perhaps to aspirate certain abdominal organs or even certain abnormalities within the chest or within the abdomen, we may require a deeper level of sedation, even if that's only for a very brief period of time.

As I mentioned earlier on, with moderate sedation, you would expect that the patient would be roused relatively easily and deep sedation perhaps less so. So thinking there might be about doing aspirates within the abdomen or chest. And with anaesthesia, as we discussed previously, that the patient would be unrouseable, in that situation.

The airway is likely to be maintained very effectively with moderate sedation, maybe with deep sedation, as I already alluded to, that airway protection is reduced and certainly with anaesthesia then tracheal intubation is required. Ventilation may be reduced with deep sedation and during anaesthesia, we're all aware we may require to intervene in terms of providing either manual or mechanical ventilation, and obviously this is something that requires control of the airway to perform, which we don't have and during sedation. So it is an important area in terms of monitoring and we'll come on to that later, in the, in the session where we look at ways of monitoring, patients during, sedation.

Cardiovascular function is usually maintained with sedation and even with deep sedation, and it's obviously something where we may require some intervention with the anaesthetized patient. We will look at a little bit about fluid therapy, and I think it's still important to consider that fluid therapy may be required, and with some patients during during sedation. So we should be ensuring that we have good patient monitoring available and that may be an appropriately trained, person, so a veterinary nurse, who's going to monitor the patient during their sedation.

We should be considering appropriate drugs, and we'll look at these options when we consider the the case examples, I mean, the second part of the, of the talk. The route of administration, we've got lots of different options here, and I think that's something that's really important to, to think about, particularly when we're thinking about cases that are not urgent, perhaps they're more routine cases, and we can actually think about whether we should reevaluate how we go about sedating those patients. And we'll look at the three main routes we're gonna consider tonight, the oral routes, the IM route, and the IV routes as well.

Even though we're not going on non-performing anaesthesia, we should still be carefully calculating and drawing up and administering drugs and utilising safe practise here to ensure good patient safety. And something I think that's really important is always to give as much sedation as appropriate for the patient and the circumstances, the procedure that we're going to perform. If you have that aggressive, dog in the clinic, and we try, small amounts of sedation initially and then we keep on having to top.

And that patient up. We're much less likely to have a good sedation out of that compared to perhaps in that if it's an otherwise healthy animal, giving, higher amounts of sedation, you know, increased dosing initially and ensuring that we get good sedation. The procedure is performed then more quickly, more easily.

We get less stress associated with that. And also we've got a patient where we've been topping up sedation. Then they're much more likely to have a much more stressful experience, and the next time they come to the clinic, the situation may be, may be worse.

So monitoring is going to be an important aspect of of sedation. We may require and may need to administer a face using a face mask, and so we can increase our inspired oxygen concentration. And we can see here where we're applying some monitoring and so we're applying ECG pads, which have already been put onto the pores and we're starting to to utilise those.

And we may want to have equipment ready to perform induction of anaesthesia if this patient is one of those ones where we've got a red flag that means we may want to consider converting from sedation into anaesthesia. It's useful to have options for monitoring equipment, so utilising perhaps some electronic means for monitoring. So we're utilising here our veterinary nurses for patient monitoring.

And there's no substitute for someone being there, who perhaps may be restraining the animal for certain procedures as well, but has a hand on to perhaps palpate pulses, is looking at the patient's chest movements. But having some degree of electronic monitoring also allows those adjuncts to be there. So perhaps things like pulse oximetry, and blood pressure monitoring as well.

They're very useful, very easy. They're non-invasive methods, and they are usually well tolerated, even in the sedated patient. And so they might be things that we want to consider adding on, particularly in those non healthy, those sick patients that are presenting for, for sedation.

So we should always be considering patient safety. This is something that's really come to the forefront of, particularly of veterinary anesthes easier in the in the kind of more recent years, and in selecting those most appropriate drugs, we're gonna go through those options over the next few slides and considering what might be the most appropriate routes of administration. I think what's really important if we have a patient that is sedated, then gaining IV access is something that I really, really recommend, allows us then to obviously top up sedation if it's not adequate, but it also allows us access to obviously convert to anaesthesia if that is required.

And it also allows us access if we have an emergency situation that occurs. And that is obviously something we should be aware of, even with the sedated patients that we may have a situation where we do require that emergency IV access, it's best, and I'd recommend to get that as soon as it's safe to do so. We should also be ensuring that we give adequate time to the drugs that we administer for them to have their the most chance of getting the most beneficial effect.

And that often means if we're using IM routes for sedation, that we should be ensuring that patients go back to a calm and quiet environment wherever possible. That's something that we certainly struggle with in our clinic to ensure that those patients have somewhere perhaps where they're not being stimulated by other. Other animals and also by the work flow in the clinic.

But if we're administering even perhaps using an alpha 2 agonist as an example, they still probably need a good 10 minutes or so to ensure that we get a maximum effect if we're giving them by the intramuscular route, quicker if we give them by the IV route. But we want to make sure we've had a maximal chance of that drug being effective before we think about giving additional sedation. I've already mentioned we may require supplemental oxygen, particularly if those patients are not healthy.

So we're going to be monitoring physiological parameters and you can utilise your anaesthetic charts to to monitor during sedation. And that's gonna form then and obviously a part of the legal record keeping from that patient and it documents that if anything doesn't go to plan during the sedation, that we have a record of that, we'll obviously be able to use that then as evidence that we have been adequately monitoring that patient. Wherever possible, I always use the IV route to top up servation if that is required.

And if we are using drugs that we can antagonise or reverse at the end of a procedure, then we should be considering that those might be appropriate to use for the recovery period and not forgetting to monitor the patient well into the recovery period as well to ensure that we have a good recovery from sedation. I think this is a question that comes up for me on a daily basis. We are asked about topping up sedations.

And really here we're thinking about the patient that doesn't sedate as expected, and it's perhaps we're not thinking about here about our kind of completely healthy young animal where we're sedating perhaps for radiography or abdominal imaging as examples, they are able to be sedated effectively with, sensible doses, with good dosing of appropriate drugs. Always look to check IV access if we're trying to top up sedation, ensuring that we have got IV access and it's still patent. Nothing more frustrating than trying to administer drugs and then realising that that IV access is no longer patent.

Always check the time since previous drug administration, if we're using again, the alpha 2 is an example, their dose dependent in terms of their, the duration of action. And if we've been utilising perhaps dexaminotomidine and we're now an hour later, it's very likely that drug is also starting to, to wear off, and we may need to be redosing at that point. Check the previous dose that was used, perhaps the dose was a low dose and we do need to, to top up.

And wherever possible, as we mentioned, we should be topping up via IV injection then to effect, so we can utilise incremental doses until we get the required level of sedation that we're looking for for that particular procedure. And so I think it's really important, even though we might be doing a procedure that's not painful in itself, so perhaps abdominal imaging, abdominal ultrasonography is an example. It may be, if we're doing radiography initially, that we need to consider whether the positioning for that procedure is painful.

So maybe it's a geriatric patient. The abdo abdomen, sorry, itself is not painful, but just positioning the patient for that procedure. Maybe they have some underlying osteoarthritis in multiple joints, and it may be just the joint positioning associated with trying to get good quality imaging is painful.

So always consider whether analgesia has been administered. If we're utilising perhaps a very standard protocol, maybe an alpha 2 with Borphen off sedation. Maybe if we find that that patient, is not tolerating the procedure, we should consider whether we would give some additional analgesia, perhaps in the form of another perhaps some new opioid agonist, to get better analgesia and get therefore better sedation.

We often see then that patients become kind of refractory to sedation and that might be a time, thing, so the drug was administered perhaps an hour ago, as I said, in terms of something like the alpha2s. And we're thinking then about the duration of action that drug and the time since we gave it as well. If we're giving a drug IV, then we expect a relatively quick onset of time, and that's true for most of the drugs that we're going to discuss during this session.

We're thinking about IM injections of drugs or even subcutaneous injections, then they've got, they may have a much longer onset time and therefore, we've got to be aware of that, in terms of administering further sedation. Always be aware there's we've, we've kind of moved from utilising perhaps a very commonly used sedative drugs to adding in things like alfaxolone, maybe people are even using propofol for sedation now. And we just need to be aware of the effects of these drugs on the recovery period, particularly if we're using low doses, perhaps of some of the IV anaesthetic agents, that if we repeatedly give them, but over a long period of time, we will get perhaps some accumulation and we may see negative effects on the recovery period.

Was really important, always consider converting to anaesthesia if necessary, and I highlights a couple of situations when we go through the case examples where it may just be more appropriate to to switch to anaesthesia, and it may be because you can't achieve the procedure that you wanted to with sedation that we've got available, considering the patient's disease status. But it may also be that the patient just doesn't sedate in the way we would expect. We've checked, we've been through all of that checklist that we looked at earlier, and it may just be safer to convert to anaesthesia in, in those cases.

Just thought I'd introduce on this slide the options that we have available. These are just some of the options, but they're the ones that we commonly utilise to to provide sedation, of the opioids. I'm thinking here about things like Borphenol, very commonly utilised to provide sedation and does provide very good sedation, generally though, in combination with other other sedative and anaesthetic drugs.

But not forgetting the use here about methadone. And maybe some clinics are still using pethidine for sedation in certain situations as well. The alpha 2s we'll discuss some dosing of both meatomidine and dexedotomidine.

I think what's most important when we talk about the alpha 2s is using the ones that you're familiar with and comfortable using, you know what to expect when you give a dose of one of those drugs. And I think there's very few situations where we would want to switch to another alpha 2. So we're using, if we're used to using metaomidine, there's a few cases where dex melatoidine might be more appropriate and vice versa as well.

Ketamine, an excellent sedative. Again, usually, and probably all of the time we're gonna administer ketamine in combination and with another sedative drug. Don't forget about Aceromazine, it does still have a place, particularly with some disease processes where we may not be able to administer alpha 2 agonists, and it may be that they use it in combination with the alpha 2s in certain situations to get that long duration of effect that we see with Aceromazine.

The benzodiazepines useful again in combination, wouldn't generally recommend these in adults and dogs, and certainly in cats, and as a loan, as a single agent, maybe in very in paediatrics and in geriatrics, they may provide some sedation. And then I'm also going to look at alfaxolone. A lot of use of olfaxolone now for sedation via routes other than the IV route for induction of anaesthesia, so that's certainly an option that we have primarily in cats, but also in dogs as well.

And they're not forgetting now where we've got some evidence coming through in the literature, primarily in terms of case reports, but also some research as well now about gabapentin and trazodone in both dogs and cats to provide some sedation. So there are lots of options then. I find generally that monotherapy is often less useful.

So we're generally using these drugs in combinations and to provide effective sedation rather than using single drugs. I think the one single drug that we may use, perhaps in the more compromised patient, would be tophenol and to facilitate some noninvasive imaging. We've got the 3 main routes of administration that we're going to consider in the case examples that we're going to go through, and that's going to be the IM route, the IV route, and the oral routes as well.

The subcutaneous route is available and may be in certain situations that we can't get a good IM injection for whatever reason. And we can consider the subcutaneous route. But I think always bear in mind when we're giving drugs subcutaneously that we're relying on the patient hydration status, and, that means that we may not get the same, or we may not get the same kind of effect from delivering the drugs via the subcutaneous route.

It's not to say that it's going to be ineffective, but it's much less predictable than delivering these drugs by the IM or the IV route. I think we all deal with those kind of stressed pets that often require sedation for relatively noninvasive procedures, so blood sampling, even physical clinical examinations in some situations, and obviously diagnostic imaging. And something that I'm kind of very aware of now is can we, we can often consider whether we can ask the pet owner to administer oral meds at home.

So can we delay the procedure? Does it need to be performed now? Can the pet go home with the client and come back and for a later appointment and hopefully then they're much less stressed when they come back for that repeat appointment.

And can the procedure, I think this one we'll come back to as we go through the examples, can the procedure be safely performed with sedation, so are we happy and that's something that we should be doing. So we'll go, we'll start to go through some case examples now. And we'll discuss these by looking at a brief bit of patient history.

The procedure that we want to perform, and then look at some options in terms of, how we might go about safely, sedating, these patients. I've split them into, into two sections. So we're going to look at our, what we call our healthy patients to start with.

So ASA 1 and 2. And then we're going to look at those patients in ASA 3 to 4 as well, where we've got more complicated disease processes, more concurrent comorbidities going on as well. So the first example here, a really a case of presenting purely because we are unable to examine this patient when it's conscious.

I think we're all, we see these cases on a very common basis. So here we've got a 9 year old, a male needs to domestic short hair, got care on its, on its clinical record. Reported to be by the owner to be otherwise healthy.

And we need to perform a physical examination, a good physical examination because we're really we're unable to do that, with the patient conscious. And we, want to, take some blood as well. So we want to do some blood sampling, to allow, a diagnostic profile, to be performed.

So what are going to be our considerations here. This is a this is a non painful procedure. And we are going to be wanting to perform our clinical examination and possibly some diagnostics and some sampling, some blood sampling during sedation as well.

This cat's going to require either intramuscular or oral sedation. And we would like, if possible, to have a relatively rapid recovery, if we can reverse or antagonise some of the drugs, and so that we minimise handling in that post sedation period and we minimise patient stress as much as possible. So what are our options here?

If this is not, this isn't an urgent or a kind of an emergency procedure, then considering giving oral medication prior to the visit or on arrival to the clinic, if that's not possible for whatever reason. And this really is where we now have some reasonable evidence to support the use of gabapentin, and I think a lot of you will have probably tried this with, with cats presenting to the clinic. And a number, a couple of studies have looked at a dose, and it seems to be the most reliable level of sedation is achieved by giving 20 milligrammes per kilo of gabapentin.

Around 2 hours prior to the visit. As I said, it can be given on arrival, but it may be at that point that it's perhaps less effective. But I think we still get relatively good success when we use gabapentin, in the hospital.

If gabapentin isn't sufficient, then trazodone is another option that you can add in on top of gabapentin. This has got a relative quicker onset time around 30 to 60 minutes. If you've not used trazodone before in this individual, I would generally recommend to administer it in the clinic and not at home the first time.

So perhaps, this cat had gabapentin at home with the client. It arrives at the clinic and we still can't perform the procedures that we are planning to do. And in that case, then we can consider adding trazodone in, as an, as our next step in terms of our sedation.

The main reason I say not to administer this at home the first time for the or ask the client to do it is that trazodone is a bit more variable. We can get very good sedation, very deep sedation, and that may obviously worry the client or it may be relatively ineffective. So if you're considering using trazodone, or perhaps kind of like dose find in the clinic, and then it's something that the client could could utilise at home, perhaps on the next time that you see them at the clinic.

Now, it may be that in this situation, gabapentin or gabapentin and trazodone is going to be sufficient for what we want to, the procedure we want to perform. If though that is not sufficient, and there's going to be some of those cats where we just cannot go on and continue, they tolerate perhaps some clinical examination, but they don't tolerate any sampling and blood sampling and other sampling we may need to require. And then we're really going to have to think about whether we can gain, can we gain IV access?

Because if we can, we're gonna be able to reduce these doses down that we've got here on this slide. If we need to perform then IM sedation. Then a useful combination of meatomidine or dexmeatomidine so metatoamine in this dose range, if we've already given gabapentin, and then we're going to use, we're gonna go down towards the lower end of this dose range and adding in borphenol in combination.

Dependent then on the level of sedation that we see, we can think about ketamine as a next step. Again, these are, these doses here are for the IM route. If we could gain IV access following gabapentin or gabapentin and trazodone, then we may just be able to use additional levels of sedation with perhaps melaomidine as low then as about 1 mcg per kilo IV2 effect.

If you're utilising dexedotomidine, then generally we think about doses that are around sort of 5 to 2/3 of the melaomidine dose. So I'd be thinking about. Still probably about topping up with 0.5 to 1 micgram per kilo, Dex on top IV.

If you're using metaomy IM then probably somewhere between 5 and 10 mcg per kilo of meatomidine. If we're unable to deliver any oral medication for whatever reason, then I would be thinking perhaps melatomidine or dexamlatamidine, butphenol and some ketamine. And you can decide whether you would mix those three drugs together and administer, bearing in mind that you may get some adverse reaction to giving ketamine an IM or you give the 1st 2 drugs and then you add ketamine at a later point.

So that the cat's already partially sedated, but it may, and it will depend on how amenable the cat is to obviously to handling at that point. If we're utilising new drugs, and we want to think about atapamazole IM for the recovery period. If we have given gabapentin and or trazodone, then we're going to see a more prolonged sedation in these cases.

And even though we reverse or antagonise perhaps on meotomidine, we may see sedation, ataxia for several hours after the gabapentin. One of our cats had gabapentin recently to go into the clinic for a procedure. And actually I found that he was a tax here about 12 hours afterwards.

I think you can see that he's certainly a geriatric cat. So let's move on to the second of our ASA 1 to 2 cases. And here, we've got a 5 year old German Shepherd, a male German Shepherd, presenting for a skin mass removal.

We've been able to perform cardiac auscultation, which is unremarkable, and the owner reports that he is otherwise unhealthy. But we can't perform any further examination and we can't really assess the skin mass. He is aggressive in the clinic.

With or without the client, and the plan is to sedate for examination and then convert to anaesthesia. So this is one where we're going to utilise both sedation and anaesthesia. And we obviously need to think about analgesia in this one, because of the fact that we will be, performing a, a surgical procedure.

Again, similar to what we mentioned for the previous cat, that if this is not an urgent procedure, we haven't seen the dog previously, then we can consider sending home if it's not urgent. And these are cases where I find we do get a reasonable response to starting trazodone prior to their visit to the clinic. If you give them trazodone when they arrive into the clinic, I find we don't get as good a response, and certainly, I think probably then we're only talking about sort of 20 to 50% or even less of dogs, and we'll respond to trazodone if they're already arrived in the clinic and they're already stressed.

If they can go home and come back for a repeat appointment, then I find it useful to ask the client, ask the owner to administer 3 doses up until the morning of admit. So we get them to start the previous lunchtime and give a lunchtime dose and an evening dose, and the morning dose on the morning that we admit. And we aim to admit them around an hour post their morning trazodone.

And I found this is something that's really kind of revolutionised the level of stress within, our dog wards, and also, to, improve, I think the kind of the both of the animal, the dog experience and also the client experience as well, of their dogs coming to the clinic. That's obviously not going to be sufficient in this particular case for what we want to perform. And, but this, I mean this is certainly a case where we want to get a good sedation with our initial IM injection, and we want to include analgesia for the surgical procedure.

It may be that this is a difficult case to monitor during that sedation, and recovery is going to obviously be a period where we're going to be less able to monitor as we would want to, in, another case. Question just to think about as we, as we kind of like muse this one is when we're gonna, when are we going to remove the IV? Should we reverse antagonise all of the drugs or not?

And what are those kind of home analgesia options that we have because this case is going to be one that's going to be likely to be discharged from the hospital perhaps sooner than we would do in, in, in, in other situations. So what are our options? We want to include a full new agonist in this, case so that we get good analgesia for the surgical procedure that we're going to perform.

We, we're gonna think about using that combination with Melatoidine. And I find that ketamine's very useful, for these kind of dogs where we want to, get good sedation, good immobility, and we don't, and we might see perhaps some really. Awakening with just the use of medicine of metatoidine and methadone, for example.

Leave them quietly for a period of time. And really things just to be aware of when we think of then about converting from sedation to anaesthesia, that with the use of our alpha 2 agonists, we're likely to see a bradycardia, and that can sometimes be heart rates down into kind of the 40s, the 50s, and we may see some brady arrhythmias as well. So perhaps an AV block or significant pauses, so quite prolonged RR intervals.

So useful to be able to monitor an ECG prior to induction of anaesthesia that we're aware that these are something that we may come across. Our IV induction agent requirement will be much lower. Those of you that are used to using alpha 2 is now in place of aromazine for patients for premedication.

Will be very well aware that the the IV induction agent requirements, so both propofol or alfaxone may be as low as a quarter of what you would expect normally or even less in some cases. And just be aware to monitor the regurgitation if the patient's been sedated for some time and then you're moving them around and then you're going to induce anaesthesia, intubate the trachea, just be aware of the possibility of regurgitation. Consider whether we can utilise any other methods of providing analgesia as well.

So it is a surgical procedure that allows us perhaps to perform a local anaesthetic technique, for example, are we going to consider adding in other analgesics here as well. So think about non-steroidals, paracetamols options and that this patient would be able to go home with, combining those together, if that is appropriate in this case. Questions really to answer.

If we want this patient to go home relatively quickly, because obviously going to be challenging to monitor and to nurse in the hospital environments, then we're very likely to want to give attapamazole at the end of the surgical procedure. And often in these cases, either then I'm removing IV access before they're fully recovered, so perhaps at the point where we've extubated here, we're ready to remove the IV access. Or we feel that it's possible later on perhaps to re-sedate through the IV so we keep an extension line or we continue with fluid therapy and then we're able to resedate, remove the IV and re-recover.

So it's just which of those options are going to be easier and for you in this situation. We'll move on, from those two healthy case examples. To now look at some patients that have got more comorbidities and have disease processes that perhaps limit our choices of of sedation.

So, the first case, to look at is a 4 year old, miniature schnauzer female neutered miniature schnauzer with elevated liver enzymes. This, she has got an abnormal bile acid, stimulation test, and, she presents as well, vomiting, in, at this time. So our initial plan is some abdominal imaging, we've been able to perform a blood sample.

And we have auscultated that there's no cardiac abnormality, so no murmur for us to consider in this patient. I find particularly with our, with our liver cases, it's really useful just to think about what the liver normally, what are its normal functions and therefore, what functions are going to potentially be abnormal in, in these, in these cases. So thinking about about drug metabolism, unfortunately, the majority of the anaesthetic, analgesic sedative drugs that we utilise rely on hepatic metabolism.

So I think it's less, it's more important to think about dosing and combinations to reduce the dose of individual drugs. We're always going to have to rely on some hepatic metabolism, and that obviously may just mean that the drug lasts for longer, but we can dose perhaps appropriately. Glucoogenesis, important perhaps in this case to monitor blood glucose and to look at that even during sedation.

Production of proteins, I'm particularly thinking about albumin here, and we're thinking about then vascular volume, so we should be thinking about providing fluid therapy, even during imaging in this kind of situation. Coagulation, important to think about this, monitor and measure and perhaps coagulation factors if we want to think about any sampling and bile acids as well as getting recirculation of bile acids. Thisation also presented with vomiting, so careful patient handling, and obviously monitoring for any regurgitation.

So our plan for sedating then for abdominal ultrasound and possible either final aspirates or biopsy if that's something you're considering in the clinic. And that means that we may be able to have a relatively light sedation, and moderate sedation for abdominal ultrasound, but if we want to then go and do any sampling, we may need to increase the level of sedation for that particular part of the procedure. This is gonna be a case where having IV access prior to sedation will be really useful.

And if, as I'm we already we already mentioned, if we are going to be considering any sampling, and it should be appropriate to consider measuring the COAGs in, in this particular situation. I'd be considering IV fluid therapy, utilising Hartmann solution, at 2 to 4 mL per kg per hour dependent on the patient and their level of, their volume status and their hydration status as well. So what are our drug choices?

It may be for the abdominal ultrasound that be tophenol, it's going to be sufficient alone. I think in a number of these cases, despite the level of disease that we see with perhaps the patient presentation and also, with their blood work, be talking alone is often not sufficient and I quite like, we quite use commonly utilised dex at very low doses IV in this situation, or if bunol was sufficient, then think perhaps about using alfaxolone intravenously at very low doses again, to facilitate a deeper level of sedation for the sampling part of the procedure. The benzodiazepines are best avoided in hepatic disease.

So these dogs that develop hepatic disease are likely to have quite prolonged effect from the benzodiazepines very heavily reliant on hepatic metabolism, and you can start to get recirculation of the benzos and also the development or the production of more of endogenous benzodiazepines as well. If you want to think about topping up sedation. Low doses again, so 0.25 to 0.5 mcg per kilo, intravenously of dexaminotomidine, or perhaps lower doses of alfaxolone 0.25 milligrammes per kilo IV of alfaxolone as well.

Just think to be to bear in mind, if the, if these become quite prolonged procedures and you repeat bolus in alfaxolone, you're very likely to have a negative. Effects on the recovery period. It's something just to be aware of and ensure that the people that the nurse is monitoring the sedation and therefore monitoring perhaps into recovery is aware that the alfaxones could have an impact on that patient's recovery.

And it may be, as we've discussed that with that hepatic dysfunction, we have a more prolonged and recovery from sedation as well. Our next case moves on a little bit from the earlier cat that we looked at a more kind of healthy cat. So now we're dealing with a geriatrics or 14 year old female neutered domestic short hair, previously diagnosed as being hyperthyroid and also previously, diagnosed with a grade 3 out of 6 left sided systolic murmur.

This cat is on, she's on thimazole, twice daily, and she remains, fractious, despite, treatment. So what of our we've got several things here to think about in terms of consideration. So we're dealing with hyperthyroidism.

We may see tachycardia hypertension and obviously a level of stress that we associate with that disease process. The murmur likely to be HCM or HCM phenotype, we may be dealing here with reduced contractility again with tachycardia and potentially with a dynamic ventricular outflow tract obstruction. We've got a geriatric patient who may have undetected renal disease, very likely in this age of cats to have renal disease present.

And we're going to have overall reduced organ function as well. The temperament. She makes things difficult for us in terms of handling and perhaps the root of drug administration and monitoring as well associated perhaps with sedation.

Drug administration I find in these, in these more geriatric cats, often they've they've got much less muscle mass doing IM injections can be quite challenging and can be quite painful for them as well. So something just to consider as we go through these other options. So we're thinking here about sedation for echocardiography to investigate the heart murmur, chest radiography and abdominal ultrasound as well.

So some very common diagnostic imaging to perform in these cases. We want to have oxygen supplementation available, and we want to leave the cat in a quiet environment as much as possible after sedation, monitoring safely, but carefully, but at a distance. And having some additional monitoring at ECG blood pressure monitoring was going to certainly be useful during sedation.

We want to secure IV access as soon as we possibly can after the initial sedation, and we want to aim, if possible, to complete our echocardiography prior to us considering an alpha 2 agonist. It's very likely that an alpha 2 agonist is going to be something that we can use successfully and safely in this situation, but we want to be aware of our echo changes or before we do so. I think this is certainly going to be a case where initial oral sedation is going to be useful.

So gabapentin, 20 milligrammes per kilo orally, plus or minus some trazodone, 5 milligrammes per kilo as well. And often find if we then hospitalising these cats that we'll drop them down to 5 milligrammes per kilo of gabapentin, 5 to 10 milligrammes per kilo, 3 times or 2 times a day, so twice daily, and utilise that while they're in the clinic to ensure that they're more calm, they're less stressed, and obviously we can manage them if they remain hospitalised. It's likely that the gabapentin plus or minus trazodone may not be sufficient in this situation.

If it's not sufficient, I'm going to think about then about some IM or even subcutaneous route of administration if there's not sufficient muscle mass. Alfaxone in the 1 to 3 milligramme per kilo dose range plus brophenol. And we can add midazolam to that, 0.2 milligrammes per kilo of midazolam.

The alfaxone volume is often a limiting factor here and certainly if you've got a, if you've got a 5 kg cat, we're talking about 0.5 mL if we give 1 milligramme per kilo. If we go to 3 milligrammes per kilo of alfaxolone, we're going to have to be using 1.5 mLs of alfaxolone.

It's quite a significant volume. You may have to like separate it, split it into IM injection sites or use the subcutaneous route. So the volume is something that's a bit of a limiting factor with alfaxolone.

There's plenty of literature out there, plenty of evidence based now behind the use of these combinations, and, certainly the higher dose, 3 milligrammes per kilos without the gabapentin component was shown to be good. And at 5 milligrammes per kilo, the safety profile was still useful as well with alfaxolone. The onset time if we're thinking about the the Alfa midazone combination is around 15 to 20 minutes to ensure that you give sufficient time for that to be effective and the duration of around 30 to 40 minutes for that combination.

So enough for some imaging, likely to have to top up if the procedures going over that sort of length of time. That effect can be variable, though. So what's our kind of next plan?

We, we should, as we've mentioned, for all of these cases, be thinking about gaining IV access as soon as it's safe and appropriate to do so. And then we can use the IV routes to top up with faxloan. If, our echocardiography suggests HCM dynamic vent output tract obstruction, a normal size left atrium, then dexametomidine or meatomidine can then be considered IV low doses, perhaps 0.5 mcg per kilo of dexametomidine, 1 mcg per kilo for meatomidine IV to get that additional level of sedation that we would require for the additional imaging that we're going to consider.

Really useful options in those in those geriatric cats. And then finally, the last case, the final case that we're going to consider this evening, a paediatric, so 12 week old, West Highland white terrier, a female and tired, with a suspected, extraathic for the systemic shunt. Procedure here, abdominal imaging to obviously look for a shunting vessel.

Similar to some of the the liver considerations that we had for that that previous case, I'm thinking primarily here about glucose, about proteins for vascular, vascular volume, coagulation and heat production as well. Then we've got our small patients, so patient size is a factor for sation in this case, of body temperature as well. IV access can be certainly can be quite challenging in these, in these smaller patients and similar to our geriatric cat, reduced number of sites for iron injection as well.

Patient age, as well as the hepatic dysfunction, also organ immaturity and our cardiac output is going to be linked to heart rate in this situation, so. A much less compliance . Cardiac system at this age, so unable to moderate or to change stroke volume associated with a reduction in heart rate.

So cardiac output is heart rate dependent. Important to think about active warming, so active warming devices available during sedation, should be monitoring blood glucose on a regular basis and obviously we can supplement glucose if our blood glucose falls below our predetermined level. Looking at checking our blood results as well, so what is our degree of hepatic compromise associated with those blood results?

Looking, in this situation, I find it very useful to perhaps clip multiple sites for IV access and to be using Ela cream, so, or one of the cold sprays that we have available now, so that we have the best chance of getting IV access. And wherever possible be using our short acting drugs, or those that we have an antagonist available to them. Having said that, we probably would be avoiding the alpha 2s because of the bradycardia that they, that we associate with them.

And that effect on cardiac output in this situation. And also that we may get quite a significantly prolonged effect and quite a dramatic, quite an intense effect from using the alpha 2s, in these situations. So we want to avoid hypothermia, we want to avoid hypoglycemia, and we want to avoid bradycardia.

And I kind of mentioned dexmelatoinine here, but really what I'm thinking about is that pethidine, it can be a reasonable option, much less commonly utilised now, I can't remember actually the last time we utilise pethidine in this situation. Borphenol. May be sufficient in a number of these cases, or very, very low doses of Dexedotomidine.

So I'm thinking here probably like 0.25 0.5 mcg per kilo of Dexedotomidine if we need some additional sedation.

Again, avoid the benzodiazepines for some of the reasons that we discussed, similar reasons, sorry, that we discussed for the liver, the previous liver disease as well. And then our, this is, sorry, this is our final case. A 5 year old male neutered, cavalier King Charles Spaniel.

We've got a 3 out of 6, left side is systolic murmur that's been confirmed as mitral valve degenerative disease and on the ACBIM staging B2. So we've got left atrial enlargement here. He is medicated with twice dailyimendin.

Coming in for a completely unrelated procedure, so intradermal allergy testing. And we've got, with stage B2 mitral valve disease, then we have got significant disease in terms of thinking about the drugs that we're going to consider utilising for sedation. So we want to be avoiding, wherever possible, significant changes in heart rate and blood pressure.

And we're going to be cautious with fluid therapy. We should be providing fluid therapy. We want to be cautious about overloading the left atrium and therefore risking pushing this patient into a congestive heart failure.

Wherever possible, similar to our two previous case examples, we want to be securing IV access prior to sedation wherever possible and utilising the IV route to enable a dose citration so we can dose to effect. And monitoring, additional monitoring in terms of electronic monitoring would be useful and supplementing oxygen. These are cases where I would supplement oxygen by face mask during the procedure.

And I would avoid alpha 2 agonists, wherever possible. So, so Aceromazine and Born IV, often when we get very good sedation and in these cases, a very low doses of Aceromazine, and we can substitute andbuorphenol with buprenorphine, and we might get still reasonable sedation. If you give methadone IV I when we don't get as good a sedation, and we may find then that we make the patient pants because of IV methadone when we give it in combination with some like promazine.

So we might find that that kind of impairs the level of sedation and obviously the patients may be distressed with that level of panting as well. If we need additional sedation to carry out the intradermal testing, then alfaxolone, small bolus of alfaxolone around 0.25 to 0.5 milligrammes per kilo will give a very good level of sedation for a short period of time.

We can also think about adding in additional butterphenol, if we've got just kind of like the past the 60 minutes and post the initial administration of the sedation. So to summarise for tonight's session, then I think really important good sedation and we can provide good sedation, will always ensure patients, good patient safety. We should be considering the patients, the procedure itself, the equipment that we have available, both monitoring equipment and other equipment, and also the team as well, how familiar are people with the drugs that we're going to select.

Always select the most appropriate sedatives and analgesics based on that patient history and the procedure. And as we've kind of been through in, in each of those case examples, the safe sedation is really going to be paramount. And don't be afraid to, convert to anaesthesia if things are not going to plan, or you need to do additional, perhaps procedures that are not going to be possible with the level of sedation that you can provide, at that time.

Carl, that was absolutely fantastic. Thank you very much. You, you've just made it so clear and, and some of the things that we should always be thinking about maybe slip away and are not quite at the forefront of our brain when we're thinking of sedations.

Sure, yeah, definitely. I think we all, we all think very much, don't we, about anaesthesia and something we do on a daily basis and You know, I think we, we can, I mean, we sedate many more patients now for procedures that we would have perhaps used anaesthesia for previously. So we do have some really good options now and there are, you know, there are alternatives to, to going straight for anaesthesia.

Yeah, yeah. Arthur's asking, why does IM Dom Taub have such a variable effect? So many patients can undergo superficial surgical procedures, and then others, you know, you can barely restrain them for blood sampling.

Yes. It's an interesting thing, isn't it? I think you know, my kind of memories from, you know, my earlier years in practise are those.

You know those dogs, they're very stressed and you give them what you think is an adequate dose perhaps of, you know, meatomidine and biphenol, and they just look at you and several hours later, you kind of wonder what you've been doing all morning and. I think some of the problems we have with the alpha 2s are certainly related to the perhaps the levels of circulating catecholamine. So if you've got a patient that's particularly stressed, got high levels, perhaps of circulating adrenaline or adrenaline, that's likely to have already somewhat of an antagonistic effect against your, your alpha 2.

So that's certainly a part of it. I think also, I guess we see a lot of patients where their body condition scores are not necessarily ideal and perhaps our injection is not quite as IM as we'd like it to be. So if we're injecting perhaps into fats, then we get a much more variable level of absorption.

So the drugs absorbed much more slowly. And we then end up with sedation that's not as good in those cases. So I think there's just, there's just variable effect associated with all of those, all of those factors.

Yeah, once you've given that IM injection and an hour later they're still sitting looking at you, you wonder if your needle was long enough to get through the 3 inches of fat. Definitely it's something you know, I think I mean that's why the IV route is so, you know, so good, but obviously we can't always get IV access without sedation. You know, in a number of patients.

Yeah, I think, I think they should put those cases on the first year competency because we, we've all done them at some point. Definitely. Carl, thank you so much for your time and for sharing with us tonight.

It really has been a pleasure to listen to you yet again and I sincerely hope we have you back on the webinar it in the not too distant future. Thanks very much. It was great.

Thanks a lot. Thanks folks for attending tonight and I hope you enjoyed that as much as I did. And to my controller Dawn in the background, thanks as always for making things run seamlessly.

From myself, Bruce Stevenson, it's good night.