Hello and welcome to this lecture on pain, recognising, measuring and managing it. My name is Hayley Walters. I am a registered veterinary nurse, and I have been qualified and in practise for over 22 years now.
I've worked in referral, charity, and also first opinion in mixed practise, done lecturing also. So I'm really hoping that I've got some knowledge that I can share with you today to make you, better at recognising pain in your patients and your cat and dog patients. Your learning objectives for today are to be able to understand the welfare implications of not treating pain because it's not just about an ethical implicate an ethical motivation.
You should also be able to recognise when a cat or dog is in pain through understanding changes from its normal behaviour, understand how to score pain using the Glasgow Composite pain scale, and understand the approach to manage pain, using preemptive and multimodal analgesia, which we'll chat about. Nobody in pain, unless you are a masochist, is having a good time. So one of the quotes I wrote that I read about was, pain is a complex, multi-dimensional experience involving sensory and effective components.
So in other words, pain is not just about how it feels, but it it's how it makes you feel. And it's those unpleasant feelings that cause the suffering that we associate with pain. Now, our patients are nonverbal.
We have to rely very heavily on owners and our veterinary skills and almost detective work to figure out what is going on with our patients. Nonverbal patients are very challenging to diagnose, but when it comes to pain, the voiceless, our cats and dogs can clearly express their suffering. Just as well as as humans who can verbalise it if you know what to look for.
So looking for subtle changes in facial expressions and body language can guide us to recognising pain in cats and dogs, just as it can doctors treating neonates, the mentally disabled, or the very, very elderly. So, why is pain detrimental and why should it be treated aggressively? Well, veterinary professionals have both a professional and a moral duty of care to animals.
When we enter the profession, surgeons take an oath to ensure the welfare of animals committed, to ensure the welfare of animals are committed to their care. And in addition, most animals are companion and companion animals, and they rely on us completely to protect their welfare, including their day to day requirements from freedom, freedom from pain. And it has been argued that animal pain is worse than human pain.
Which goes against the myth that we've had for ages that animals don't feel pain, like we do. So animal pain is often is believed to be worse than human pain, because animals are thought to live in the here and now. And unlike a human being in pain, they are not aware that the pain is only temporary, and it will be relieved given time or treatment.
So in in addition to the ethical arguments of treating pain, there are a number of well recognised physiological and physical consequences of untreated pain. These include an increased stress response with the release of catecholamines and pituitary hormones and therefore a catabolic state leading to weight loss and potential wound breakdown. And if you have ever suffered acute pain yourself, like I have, you might remember that the last thing you want to do is eat.
And this is certainly catastrophic for young puppies and kittens. It's miserable for the patient and it's really distressing for the owners too. And even with the best surgery in the world, if you are not treated, if you're not eating and getting your daily requirement of nutrients, you are not going to get better.
And this increased stress response can also lead to wound breakdowns. This has been well documented in humans and we can assume the same for our cat and dog patients. OK.
Animals with a weakened immune system have an increased susceptibility of experiencing infections. So when they're painful, we have a poor immune function. And those animals that have that poorer immune function are more likely to get infections more frequently than most other animals, and these illnesses might be more severe or harder to treat.
They might also find themselves dealing with an infection that an animal with a stronger immune system would not get, such as, bronchitis or skin infections, anaemia, and, digestive problems. So there's another good reason to treat pain. Why else?
Impaired respiratory function. Every single breath is painful, so you may get a reduced respiratory rate leading to hypercapnia. So an excess of carbon dioxide in the blood, which can cause effects such as headaches, dizziness, and fatigue, as well as serious complications such as seizures or loss of consciousness.
Or you may have an increased respiratory rate leading to hypocapnia, so a deficiency or a lowering of carbon dioxide in the blood. This can result in a respiratory alkalosis and eventually hypoxia. So the reduction of oxygen delivery to tissues.
So, also another good reason to treat pain. What else do we have? An increase in heart rate and blood pressure.
This is absolutely disastrous. If you are doing surgery or you just finished surgery, there's the surgeon has tagged off all those little bleeding blood vessels really nicely. Everything is hopefully clotted, or hoped that they will clot, and then the animal starts to bleed profusely due to high blood pressure.
This is not ideal at all. Patient interference, therefore, increased wound healing times again. So if a patient is interfering with the wound, it is not going to heal, and it could potentially lead to the development of chronic pathological pain.
I'm sure by now you know that a dog or cat can open up a fresh surgical wound in just a few minutes, with just a few good licks and a few good shoes. I've seen it happen. And it's not been a great day.
And in just about the time it takes you to locate and put together a buster collar, that wound can be open. And so back into the theatre, they must go. But it's worse still, if they, if the animal's actually gone home and then they've done it at home, and then the owner has to bring the animal back in for it to be re-sutured.
And obviously, that excessive wound licking can also lead to infection of the wounds, and then, and also wound breakdown. OK. We can see behavioural changes if we don't treat pain and depression and sleep disturbances have been reported in humans.
So, behavioural changes such as aggressive responses to being handled, when normally they're pretty placid about being handled, a refusal to exercise an ability to access their important resources like food and water. An inability to groom, we might see vocalisation, an inability to settle, disinterested in their surroundings, etc. Etc.
And when animals are suffering from pain, the effect on their resting level of emotional arousal can be significant. And so as a result of this, of this utilisation of their emotional capacity, dog or cat may be less able to cope with other emotional situations. And a very interesting fact that I discovered a few years ago is that in the UK around 72% of referrals to behavioural specialists, behavioural animal specialists.
Are linked to acute and chronic pain. So this is a huge problem that needs to be addressed. Lots of those behavioural problems that we see in cats and dogs are due to pain.
OK. Poorly controlled acute pain can lead to chronic pain. This is widely reported in humans.
So chronic pain is pain that persists past, several weeks. Chronic pain is widespread in the human population. I'm sure we all know someone who has experienced or is experiencing chronic pain, and it's a very, very miserable existence for them.
So it might be from a primary condition such as osteoarthritis or cancer, or as an ongoing problem following. This is very interesting, poorly controlled acute pain. So chronic pain syndromes have long been recognised as a substantial problem following certain types of human surgery, such as limb amputation, hernia repairs, and mastectomies.
But it wasn't until quite recently that it's been shown that there is a considerable relationship between poor controlled pain at the time of surgery and the development of chronic pain states. And it was assumed for many years that suboptimal analgesia to treat acute pain in surgery had no long term consequences in humans, but we now know differently. It is difficult to assess whether chronic pain states in animals occur following suboptimally managed surgical pain, but there should be no doubt amongst us, that animals do suffer from chronic pain.
It is, it is, probably massively underdiagnosed in our patients. As I said earlier, they are nonverbal, but in the human field, self-reporting from the patient to the doctor is obviously possible, which is why we have learned about it. Client dissatisfaction.
So overall, these physiological changes are likely to lead to an increase in postoperative complications in our surgical patients with poorly controlled pain, as well as client dissatisfaction with yourself and with the veterinary practise. So the economic and time losses alone could be significant as the complications that occur with that patient are generally treated by the practise, either for free or at a reduced rate. So nobody wins when the patient is in pain.
The animal doesn't win, the practise doesn't win, and the client doesn't win. So there's a whole plethora of reasons to be treating pain. And it's not just because we don't like seeing cats and dogs in pain, which is my first number one motivation.
But for anyone who's a bit stingy with their pain relief, you can blast them with that list if you need to. OK, so how do we recognise pain in dogs? Before I show you these pictures and videos, I just want to make it quite clear that all of these photos were taken opportunistically.
And nothing was intentionally hurt so that I could take the pictures or or the videos. OK, so dogs have amazing, body language and, facial expressions as well, and they're constantly communicating with us and with each other. And because of this and their sociable nature, I think it is often fairly easy to tell when a dog is experiencing pain.
So some of the telltale signs might be not wanting to be touched. So they're at the back of the cage and they're hiding. Now, this is when it's important to know what the dog's behaviour was like before the surgery happens, so the painful event happened, because if they're at the front of the cage, interested, saying hello, and now after the surgery, they are, Excuse me, they are now at the back of the cage.
We can probably assume that the pain is not being well managed, not wanting to be touched. OK, if they're disinterested in their food or surroundings, so if we're seeing behavioural changes like that, again, that can indicate that this animal is in pain. Interfering with wound or guarding the wound in any way, just even looking at the wound, is a sign that, that wound is uncomfortable for them.
And by guarding the wound, I mean that when you go to touch it, to either clean it or palpate it to see, to see if it is painful, if they look at you or growl at you or snap at you, that's a sign of pain. The prayer position, this one is a little bit unusual, but this is what we can see when we have, poorly controlled abdominal pain. So the dog is down on its elbows with its bottom in the air.
Now this is never to be confused with a play bow, that invitation to play that dogs will show to us and to each other. One, it would be unusual to see it on an examination table, like in this picture. But two, with a play about the tail is always high in the air and usually wagging side to side.
So this must not be ignored. And sometimes you'll see dogs leaving the kennels to go back to their owners, and they'll get in this, this prayer position, and they may maybe think their bottoms on the floor as well, and then stand up and walk out. So please don't ignore this and, and be asking or thinking about giving more analgesia to these poor patients.
If they're tense or rigid, reluctant or unable to move, that should be alerting us. Altered breathing, as I mentioned earlier, the increase of the decrease in respiratory rate, and if their head is hanging down, they've got that hangdog expression, lower than the shoulders indicator that these, this dog is in, a lot of discomfort. Continuing on, if we've got squinting of the eyes or orbital tightening, as we can say, pulled back ears, tense face, altered postures with hunched tense abdomens or vocalising, that should all be alerting us to pain.
You can see these little puppies here. If you think of yourself when you're in pain, your face is not relaxed and and smiling. You've got all tension and Tightness in your face.
And I think one of the first ways that I was ever taught how to recognise pain, very rudimentary way of, of recognising pain, after abdominal surgery, is that tucked up abdomen, and that's that hunching of the spine. We can usually spot that one a mile away, but as, as I've said, there's lots more subtle things that we can see, like the facial tightening or those behavioural changes. OK, pain in cats, right.
Cats, even though they are predators themselves, they're also a prey species and therefore they may appear more stoical and exhibit less, obvious pain behaviours compared to a dog. So cats are quite stoical creatures, I think we'd all agree, and showing signs of pain could make what is a solitary survivor vulnerable. And therefore they tend to show more passive signs of pain, and they're far far more likely.
To be passive more than the obvious signs that we associate with our canine patients. So what might we see a cat doing? Well, hunched with their legs straight, very unusual posture, this for a cat, unless it's just woken up and it's stretching, but it wasn't.
This cat was standing like this for, for quite some time before, It was spotted and analgesia was given. So look at that tucked up abdomen, that hunching of the spine, and that real, almost locking of the knees and elbows there with its straight legs. With the cats, we can get the slanted or squinty eyes.
So this little kitten is not in pain. It's eyes, if you go From its lateral to medial, medial to lateral canthus and to draw a line through it, that line is quite straight. But if you look at this cat that is in pain, we've got more of a V shape going through the canvases there.
That can indicate us that this cat is not in the least bit comfortable. That does not look like a relaxed face. If they're recumbent, tense or rigid, look at this cat.
That is not a natural cat position. That is a very, very unhappy cat. You can see those ears out to the side as well, and that really tense.
Everything hurts, air about it. If they hiss or flinch or claw when you try to touch them or, or get close to them, then that can be, a, a, a really easy and slightly dangerous way of, proving, recognising that that cat is in pain. So again, super important that we know what that cat's behaviour was like and its body language was like before the pain is inflicted.
So that we can tell if there's differences after the surgery. OK, continuing on with cats, if we see behavioural changes, so back of the cage, now hiding, whereas before it was at the front of the cage. Alarm bells should be ringing.
Altered breathing, as I said, increase or decrease in the breathing, vocalising. It's a very painful cat that draws attention to itself, when it's in. The clinic with you.
Normally they just want to be quiet and hiding away. So if they're actually crying out, then we really do need to be offering that cat, but certainly pain scoring that cat and offering more analgesia, more than likely. If they're disinterested in their food, in grooming, or in their surroundings, again, that's when we should be paying attention.
You can see this. Cat here, hopefully down its legs and chest and around its face. It's not been grooming for some time, which is what alerted this owner, to bring the cat into us.
And so that, that change from normal behaviour, was, yep, justified. There was a huge, ulcerated tumour under this poor cat's tongue. If we have an altered posture.
So it might be something very obvious, like this guy here who's had had abdominal surgery. We've got the head hanging way below the shoulders there, for a cat indicating pain. We've got, rigid legs.
That's just a very unnatural cat position. And this, this cat was almost frozen in this position. But we might have something a bit more subtle, like this position here.
And I photographed this cat because he was, I thought that was casual for a cat in the clinic. And then when I looked again about 30 seconds later, he was still in that position. And he was in for X-ray, and once we had the X-ray results back, there were two large tumours in his abdomen.
So that's, that is quite subtle that, but it's those changes in normal cat behaviour and normal cat posture that can really be letting us know, and getting a bit more in tune with our cat patients that they are in pain. Now I have to add here. That some of the descriptors that I have just mentioned may be exhibited due to other factors such as stress or illness or fear, and therefore they cannot all reliably use to identify pain.
So increases in respiratory rate may just be that the animal is hot or excited or have just exercised. Vocal dogs may be asking to go to the toilets and hissing cats may just actually be very scared. So all although a lot of what I've just mentioned is recognised by vets and nurses and ANAs and ACA as indicators of pain, it is open to personal interpretation by the observer.
So pain recognition can be really subjective to people seeing the exact same thing can disagree. And this can be down to individual feelings, your own health status, and also your experience with cats and dogs and being in the clinic. So what can we do?
Well, hopefully you've all heard of the Glasgow canine composite measure pain scale. It was developed for dogs initially in acute pain. So pain from surgery, so, surgical pain, medical pain, inflammatory or traumatic pain.
And it was designed as a clinical decision making tool. It has been shown to be valid, reliable, and it can be used in a range of clinical settings. It's very easy to use a complete and anybody can do it.
It's a questionnaire. It contains 30 descriptor options within 6 behavioural categories. And then within each category, the descriptors are ranked numerically according to their associated pain severity.
At the end, so within each category, the sorry, the person carrying out the assessment chooses the descriptor within each category, which best fits the dog's behaviour or condition. And then a score is generated at the end and the higher the score, the worse the dog's pain is. OK, so, I'll go through this quite quickly.
If we look at the dog in its kennel initially, if it's, if he's quiet, you score 0, crying or whimpering 1, groaning 2, screaming scores of 3. So here we're just looking at the dog's vocalisation. If the dog is ignoring its wound or painful area, it gets a 0.
Look at it 1, licking it 2, rubbing it 3, and chewing it 4. So here we're looking at attention to wound. Now, the Glasgow pain scale does not come with pictures on it, but I, I hate putting slides up without pictures on it.
And it also has prompted me to have a word about Buster collars. Buster colours, Elizabethan collars, cones of shame, whatever you like to call them, do not address the issue of pain, nor do the inflatable donuts, or whatever it is that your practise likes to use, post-surgery. And some practises routinely put buster collars on post-surgery, whether the animal needs it or not.
Buster collars merely prevent the animal from doing the only thing it can do to alleviate its pain, which is licking. If I was nonverbal and I had a headache and was rubbing my forehead to relieve my pain, I would sincerely hope that if someone saw me doing that, they would give me some paracetamol and some ibuprofen rather than tie my hands behind my back. So Let's not lead to Buster College straight away.
Let's think about giving more analgesia because research also shows that Buster cos cause a lot of stress for the patient, and we know that stress decreases wound healing. Decreases the wound healing. And it also causes stress for the owner as well, and it reduces normal activities for the patients, such as eating, which we want them to do, sleeping, which we want them to do, grooming, and also even walking.
They're really negative, and I'm gonna say it, they're lazy vetting as well. If you have Good sharp clippers when you are prepping your patient, you do a thoughtful scrub. If the tissue handling is gentle, if the sutures aren't too tight, and, and if you give adequate preemptive and multimodal analgesia, which I'll talk about in a bit, there is often no need for a bus to collar.
So there are cases where buster colours are certainly justified. I'm not doubting that for a second, but we should not be reaching for one automatically after every bitch they, dog castrate X lap. OK, that is one of my biggest bugbears, and I shall now move on.
OK. Next on the list, we need to put a lead on the dog and take it out of its kennel. If it's had spinal surgery or, or pelvic or, or, or limb fracture surgery, don't do this section.
Just go straight to see. But, put the lead on the kennel and notice when the dog gets out of the kennel, is it? Normal, 0.
Is it lame? 1, slow or reluctant, 2, stiff, 3, refuses to move, 4. Circle the number which best suits you.
And I know that in my early days, when I was a very young, naive, veterinary nurse, if the dog didn't want to come out the kennel, I used to just tug on the lead and try and jivvy it along. Come on, come on. Out we come.
Come on. Oh, and that poor dog was trying so hard to tell me it was painful, and I missed a massive sign of pain. And this is why I'm so passionate about teaching about pain recognition now, because I made mistakes in the past.
I didn't know better, but I now do, and I want to pass on as much knowledge as possible. OK, now, see, this one can be a little bit controversial because you, some people say you're almost, causing pain to see if you have pain, inflicting pain to see if you have pain. Well, some people call it the poke the wound test, but it is actually a really, really good way of checking if your patient is comfortable and you don't have To be rough with them.
You just apply some gentle pressure 2 inches around the wound site. If the dog does nothing, absolutely brilliant. It scores a 0.
Looks round, just that little glance, that's a 1, flinch 2, growl or guard that area 3, snaps at you 4, cries out, that's a 5. Oh apologies. So for B we're looking at mobility, and for C, we're looking at response to touch.
OK, now, overall, we're looking to see if the dog is happy and content or bouncy, 0, if he's quiet, he gets a 1, indifferent and unresponsive, 2, nervous or anxious or fearful, 3, depressed or nonresponsive to stimulation 4. So there we're looking at demeanour. And then finally, we're looking at the dog's activity.
Does he seem comfortable, unsettled, restless, hunched or tense, or rigid? And then you add your scores up. If you do the entire, the entire scoring, it's out of 24.
If you score 6 or more, then you need to give more analgesia. If you miss out the taking out, and putting on the lead and taking out the kennel because the dog's immobile, you score out of 20, and if it scores 5. 5 or more out of 20, then you need to give more analgesia.
Once you've given your analgesia, or spoken to the vet and they've given more analgesia, you need to go back about 20 to 30 minutes later and rescore your dog to make sure that It has worked, that it was adequate, and it was the correct type of analgesia, and the dog doesn't need any more. So it's not a tick box exercise, pain score, score is high, give analgesia a tick, that's done. You need to go back and check it has worked and that it's continuing to work.
If you score lower than a 5 or a 6, but you know that patient and you do believe it is painful, give more analgesia. What have you got to lose? It's almost never contraindicated.
And other than the additional expense to the owner, you really have got nothing to lose. And then once you give it, you can re-score again and probably prove yourself right that you were correct. OK, this is a dog that had had ex-lap surgery, an 18 month old cocker spaniel.
And this is what he looked like before he got his post-op methadone. He had it preoperatively. Methadone lasts around 3 to 4 hours.
He was now 4 hours post-surgery, and this is what we were seeing. So you can see here we've got that very obvious tucked up abdomen, hunching of the spine. Now we've got licking of the nose, which is a sign of anxiety.
So the pain is probably making him anxious. His head is, is hanging a little, panting, we cannot use that as a sign of pain, but we can use it as, as him being a bit stressed. He's at the back of the cage.
He is looking away. He's trying to stay away, from me, who's filming him. He cannot get settled.
He can't get comfortable, more li licking, pretty, unhappy, uncomfortable dog. Not normal behaviour at all for an 18 month old cocker spaniel. OK, so he was pain scored, deemed painful, and this was him after his methadone.
This was 30 minutes after methadone, so I came back to check him and we're seeing a much different picture here. He's now facing out. He's not licking his nose, panting, he's not got his tucked up abdomen or the hunching of the spine.
He's got a nice relaxed face, his head is shoulder height or just above. He's happy to be touched now. He's even sniffing the bed, so he's interested in his surroundings.
Much, much better, more comfortable dog now. Cool, and then he would be rescored again later, and he was actually put down for 4 hourly methadone until the next day. OK, now there is a cat one.
It, it is more the more recently developed, and so it's still new on the market. Not everybody's using it, but we absolutely should be, because, as I mentioned earlier, cats are much more subtle when showing pain. So, first of all, we need to look at the cat in its cage, and very straightforward, this one, if it's silent purring or meowing, it's 0.
If it's crying, growling, or groaning, it's a 1. Any vocalisation from a cat scores a 1. Next, is it relaxed?
0. Licking lips, restless carrying it back a cage, tense or crouched, rigid or hunched. Let's make a decision and score the number.
And then I like this one because ignoring any wound or painful area scores a 0, any attention to the wounds so straightforward, gets a 1. Any licking of that wound, your cat gets a point. Now the caricatures are brilliant.
So you circle the drawing which best depicts the cat's ear position. So if they're facing straightforward, that's great. Try not to talk to the cat when you're doing this, or have any noises in the room because their ear position will automatically change as they hear noises.
If they're slightly out to the side, it's 1, and if they're right out to the side, they score a 2. Sticking with the caricatures. We're now looking at the shape of the muzzle.
Now, when I first saw these caricatures a few years ago, I was like, What? They all look exactly the same, but they're not. The more painful the cat is, the tighter the tension is on that muzzle and the smaller it looks.
It is a bit tricky to do on the black cats. They're at the back of the cage and the room's darkened. Try your best.
I do hold this picture up to them so that I can try and do this as accurately as possible. OK, circle your caricature. Next, approach the cage.
Now you can call the cat by its name and stroke along its back from head to tail. If it responds to stroking and by responding to stroking, we know that cats will reach up into our hand, put their tails in the air, and then let us stroke them. And if it does this, which is what we want, it scores a 0.
If it's unresponsive, it scores a 1, and if it's aggressive to you, so you do have to be careful when you do this. Aggressive in any way, hisses, well, swipes out with its paw, turns its head round to bite you, that's a 2. OK.
Wound or painful area, apply gentle pressure, 5 centimetres. You can tell this is newer because we're in centimetres now, not inches around that site. If there is no painful area or no surgical site, just use similar pressure around the hind leg above the knee.
You have to be applying pressure to this cat somewhere to do a complete, pain scoring. If the cat does nothing, that's perfect. That's what we want, a 0.
You have to be observing the whole cat as you do this, because if you see that tail swish, or the ears flatten, that does score a 1. So you do have to remove any blankets that are on them so that you can fully assess the cat's, response to this. If he cries or hisses too, growls at you 3, bites or lashes out, that's a 4.
And then finally, your general impression. Happy and content, 0, disinterested or quiet one, anxious or fearful 2, dull 3, depressed or grumpy, scores of 4. Add up all your points.
This one's even more straightforward because it's a straight out of 20. And if the cat scores 5 or more Out of 20, then you need to be giving more analgesia. Go back 20 to 30 minutes later, pain score again, check your analgesia has worked.
But again, if you feel that cat is painful and it's scored lower than a 5, give more pain relief. You have nothing to lose. It is rarely contraindicated.
I see pain scoring as a way of confirming what my initial feeling was on that animal. If I see a dog and I think, oh, you do look painful, I score it, and therefore a number is generated, which cannot be argued with. If you have colleagues who are resistant to giving analgesia, for whatever reason, they're stingy with it, then Showing them the pain score, which confirmed what you originally thought, can't really be argued with.
It's like showing someone the numbers on a thermometer and them saying, well I don't believe you. Science is science. This has been validated.
The number generated is generally how that animal feels. OK. This is, a little picture that I like to show, that shows the caricatures quite nicely.
So the cat on the left, this is the same cat, but the picture on the left was a cat that had had an awful tail injury and had come into an emergency vets to be treated. And as you can see, his ears are out to the side. I would probably score his ear position as a one.
And his muzzle is super, super tight. You can see those whiskers sticking out to the side and that, and that really tightening of the muzzle. So I'd probably score him a 2 on his muzzle tension.
And then we gave him methadone, and then you can even see the difference in his eyes. Well, his pupils, definitely, but his eyes look more relaxed. His ears are now facing forward.
I'd score them a 0, and his muzzle is, is much more relaxed. I'd probably still score that a 1, because it's not fully, fully relaxed, but you can see that the whiskers are now drooping. And which is a much more natural.
Muzzle position for a cat. So the caricatures are helpful, but as I said, I do like to hold them up to the cat's face, so I do it accurately. And here is, a picture of, the cat you saw in an earlier slide, who'd had, liver biopsies taken, intestinal biopsies, obviously via an exploratory laparotomy.
This picture is of him after surgery, so we've got the head hanging low, below the shoulders, squinting of the eyes, ears slightly out to the side, stiff front legs, tucked up abdomen, hunching of the spine, really unnatural position. This is him actually 30 minutes after his methadone. The second picture I've just shown is him 80 minutes after his methadone.
So you can see that methadone in that top picture was not quite cutting it straight away. And then later he did become a bit more comfortable. Head is still a bit low, ears are still out to the side.
We've still got a lot of muzzle tension there. Look at that muzzle. That's so tight.
Squinting of the eyes as well. And then Oh apologies. The first picture, sorry, Dawn, can I record that slide again, please?
I'm just gonna go back. Yeah, of course, just go to the top of the slides. Thank you.
Thank you. I've got mixed up with my timing, sir. OK.
OK, back to the picture I showed you earlier of our cat that had had an exploratory laparotomy for intestinal and liver biopsies to be taken. You can see how utterly uncomfortable he is with his head hanging below his shoulders, his ears slightly out to the side. We've got tightening and squinting around his eyes.
His muzzle is so tight, his whiskers are almost sticking up straight front legs, tucked up abdomen, hunching up the spine. This is not a comfortable cat in the sly. So he was given intravenous methadone, and this was him 30 minutes later.
So we've got a slight relaxation in the body there. Eyes have relaxed a little bit, but that muscle is still quite tense. And the ears are still a little bit out to the side.
It's an improvement, but it's not better. And then this is when I checked in 80 minutes after, 80 minutes later after that initial picture was taken. So we've got ears more facing forward, a definite relaxation around the eyes, and then a much more relaxed muscle and a much more natural position, with his body and his legs.
So we need to keep on checking these patients and checking that our analgesia is sufficient. This last picture is, is obviously not perfect, but it is a big improvement on that first picture. OK, little video of a cat now.
This is a cat preanalgesia, after having his leg, his fractured leg repaired. It was fractured and he had, pins and screws with it, placed. And this is him post-surgery, and this is 44 hours after he was last given a methadone top-up.
So he had methadone pre-surgery, and then a top up during surgery, and this is 4 hours since the last top-up. So. Hopefully you heard him vocalising there.
Squinting eyes. Not wanting to be touched. Oh, get off me, he says.
Put himself at the back of the cage as far as away as he can manage. OK, so he was scored, deemed painful. I mean, he looked painful anyway.
Your score just, just validates what you thought, just confirms what you thought. And this is him after his math, after his buprenorphine. So, you can see that he's happy to be touched now, he's responsive to the touch.
He's at the front of the cage. Now buprenorphine would not be my analgesia of choice after orthopaedic surgery, but, he was about to go home and the vet didn't want him to be too, too spaced out. So much happier cat, happier to go home with.
And with some owners, we will send them home with buprenorphine. So for the transmucosal buprenorphine. Well, that's up to the individual vet if they are happy to do that or not.
So, as I said, use your pain score to back up your clinical judgement that the animal was painful and with time and experience, you will soon be able to just look at a cat or a dog and know that it is painful. It's just there to back up your suspicion and put a number on that score. So, as I said, this is really useful when you're working with colleagues who aren't so experienced with pain scoring, or you're finishing your shift and handing, that patient over to a colleague.
And then therefore, they have a number, a measurable number that they can use to see if the animal's getting better or not. And it's also an accurate means of measuring. That the analgesia you gave 2030 minutes ago has actually worked.
So when you're TPRing all your patients, pain score them as well, it really takes not much extra time. We're trying to save the planet, so don't keep printing out more paperwork, just print out several, laminate them and put one on the front of each of the kennels, stick them to the kennel walls or whatever is easiest in your place. But What I find even better still is if you ask any nurse what they've got in their pocket, they will normally say scissors, pen, and their mobile phone.
So I screenshot it. I've put it in my favourites. I have to, because I've got almost 7000 photos on my phone now.
I only got 12 things in my favourites. And they're the, the Glasgow pain scales. And then when you're sitting looking at that animal, you can just whip out your phone.
Everyone can add up twos and threes. And then your score is there. Super easy, and it's what most of my colleagues do now as well, just so that it's so human behaviour change is really difficult.
So if you can make, make things easy to do in practise, people are more likely to do them. OK. Pain is complicated, and the more you read, the more you find that you don't know about pain.
And I don't know about you, but I actually find it a real turn off when I start reading about A and C, delta nerve fibres and new receptors and spino reticular tracts and all that. I'm not particularly academic. I, will admit that.
So, but it is important to have a basic understanding of how pain is transmitted so that you can understand how to treat pain. So the pain pathway begins with the pain receptors, or the no receptors, which are found throughout the entire body, the skin, peritoneum, the pleura, the periosteum, a huge list of places those receptors are found. And those receptors, got to remember, are free nerve endings or groups of neural fibres, and they signal the presence of harmful, the harmful thermal, mechanical or chemical stimuli.
And when a noxious stimulus is experienced, so a scalpel comes at you, 3 separate processes take place. The transduction The no receptors at the site of the painful event changed the chemical thermal or mechanical energy into electrical impulses. Then we have transmission.
These electrical impulses travel from the site of the painful stimulus to the dorsal horn of the spinal cord and then carry the pain signal on into the brain. And then modulation. This refers to the process by which the body alters the pain signal as it is transmitted along the pain pathway and explains at least in part why individual responses to the same painful stimulus sometimes differ.
There are endogenous analgesic systems in place in our body, and these release naturally occurring analgesics known as endorphins. And these hinder the processing of stimuli within the spinal dorsal horn cells. So in other words, there are some analgesic properties naturally residing within our body.
And then we have perception. Now perception is not part of the nociception process, as there are no no ciceptors in the brain. Perception is the result of this process.
So when an animal is under anaesthetic, it cannot perceive the pain, but sometimes you will see a physiological response, like when you pull on the ovaries or start drilling into a bone. And that's no deception, because that transduction, transmission, and modulation is taking place and the brain is being well informed about all those painful things, about the painful event happening, but the animal is not conscious and cannot perceive the pain in that moment. But we still see physiological reactions to it.
However, when the animal becomes conscious and is recovered from its anaesthetic, it can certainly perceive that pain that has been happening whilst it was unconscious. So I mentioned multimodal analgesia before. Hopefully you all know that multimodal analgesia is the combining of two or more drugs.
Sorry, my slide's running away with me. 2 or more drugs from different classes to manage pain. So different drugs act at different sites along that pain pathway to provide optimal analgesia.
I liken multimodal analgesia to making the perfect cocktail. You need a little bit of everything to make that cocktail perfect. And they're different classes of drugs, so they can be safely used together.
And combining different classes of analgesic drugs ensures a more effective, effective and enhanced management of pain, just like making your perfect cocktail, creates a synergistic effect and therefore lower doses of Each drug can be used, which reduces the possibility of side effects. So it's a win-win for the animal and also for you because you're not panicking that you've maybe depressed that respiratory system too much or the cardiovascular system too much because you're you're making a nice cocktail of drugs. To work synergistically.
OK, so what drugs are we looking at in multimodal analgesia? Well, local anaesthetics, they block the, the impulse conduction in nerve impulses. They're cheap, they're readily available, extremely effective, and when used correctly when used correctly, but they're often really underused.
Lidocaine and buppivocaine are your local anaesthetics, and local anaesthetics are your only true analgesics. They will completely, if done properly, if the block is done properly, stop the pain, signals from reaching the brain. If you've ever had a local anaesthetic and you're conscious, it's incredible how powerful they are.
And they help prevent that wind up from happening, which I'll talk about in a second. Ketamine also helps to prevent the windup phenomenon. It helps potentiate the postoperative pain analgesics, so the drugs that you do give postoperatively will now work better because you've given ketamine.
It's a really useful drug for patients undergoing major surgery, and when a chronic pain state is a risk, so like a limb amputation in humans, very often when you're doing an amputation in a dog or a cat, a ketamine CRI is a really good idea. And now there's good evidence to support the giving of, a little, a little loading dose of ketamine pre spay, pre-bitch spray, and you'll see a much, reduced pain response. Or no, no ceception during that pulling of the ovary, during that surgery and you won't need to hopefully give much more analgesia.
Dawn, sorry, can I do that, that slide again because I've just added that bit in and I've not practised it. Yeah, of course, just go to the top of the slide again. OK, thank you, sorry.
OK, what drugs can we use for multimodal analgesia? Well, local anaesthetics. These are the only true analgesics.
They will completely block the pain signals from reaching the brain. They are cheap, they're readily available. They're extremely effective when used correctly, but they are very, very often underused.
All dental extractions should be done with lidocaine or buppivacaine on board. And we can be injecting this intramuscular. Around our site before we close as well.
As I say, often very underused, but if you've ever had a local anaesthetic used on yourself, you will know how incredible it is and how effective it is and how happy you were to have had it because you can't feel anything once you've had a local anaesthetic. Obviously, it wears off, after a few hours. Lidocaine wears off faster than puppica, but it helps to prevent wind up, which I'll talk about in a moment.
So ketamine helps prevent the windup phenomenon as well. It helps to potentiate postoperative pain analgesics. So any post-op analgesics that you give will work better because you've given ketamine.
It's a useful drug in patients undergoing major surgery where a chronic pain state is a risk, like limb amputation in humans. When, doing a limb amputation on cats or dogs, a ketamine CRI is a really good idea. To help prevent the windup phenomenon and also giving a dose of ketamine, before, you are pulling on the ovaries during a bitch day is also a really good idea.
You don't see the responses that you often see when ovary pulling if you've given some IV ketamine first. Opioids. So these decrease the perception of pain.
They don't block it completely like a local anaesthetic will. They decrease the reaction to pain and also increase pain tolerance. So what would have been utterly unbearable is now made bearable when opioids are, are given.
So they bind to opioid receptors in the nervous system and inhibit the release of excitory neurotransmitters in the brain and spinal cord, thereby reducing the pain from a noxious stimulus, so a scalpel without interfering with motor function. And your opioids are morphine, pethidine, methadone, buprenorphine, fentanyl, Borphenol, a weak opioid, and tramadol, which only works in 50% of patients. So we shouldn't really be throwing too much tramadol around unless we know it does definitely work in that particular patient.
Non-steroidal anti-inflammatories are NSAIDs. They have antipyretic, anti-inflammatory and analgesic effects. And often if you've got owners who really aren't that happy to be spending their money on pain relief, then you can just say it's an anti-inflammatory.
And depending on how you sell it. The client can make them happy. So lots of clients are happy for their animal to have pain relief.
Some, some owners don't want to spend the money on pain relief, so you can call it an anti-inflammatory. You're not lying, you're just selling it in a different way. So that's our carprafen our meloxicam and our onsor.
And then finally we have paracetamol. Again, a really underused drug, only use it for dogs. It says toxic to cats.
Oops, my slide's running away. It's not considered an NSAID because it doesn't exhibit, a significant anti-inflammatory activity on COX 1 or 2, which is the housekeeping and prostaglandin production. It's really good for head trauma patients as it reduces the amount of opioids needed.
And as we know, opioids can reduce the respiratory rate, which increases carbon dioxide, which can increase intracranial pressure. So intravenous paracetamol, for dogs, never for cats, is, is under use and is a really effective drug. So there's our lovely cocktail for multimodal analgesia, or can be safely used together and, and should be, should be used together when, it's required.
OK, I'm not going to talk about this slide too much. This is one that you can pause on, but it's just a great graphic to show where these different drugs work along the pain pathway that I talked about earlier. So you can see why you give so many different drugs because they work at different points.
I had an owner say to me when we sent their dog home with, Paracetamol and a non-steroidal, and I said that he'd had opioids during. They were a little bit off, and they said, sounds like he's needed a lot of pain relief. Sounds like you're overdosing him.
And so I I just quickly explained, they work at different points along the pain pathway, and therefore, we're gonna get a nice analgesic effect on the dog. That's all they needed to hear. They were worried that we were giving too much.
I am never worried that I give too much. I am so pro analgesia. Wind up, OK, I mentioned this.
What is it? Wind up, if wind up happens, oh, sorry, Dawn, I'm really sorry. I'm rusty.
OK, don't worry, it's fine. Sorry, sorry. OK.
Right. Wind up. OK, what is it?
So when pain is treated inefficiently, a phenomenon called windup occurs. This is the process by which repetitive, noxious stimulation bombards the spinal cord with pain signals. And the pain signal that comes into the central nervous system becomes stronger and stronger.
Now anaesthetized animals cannot protect themselves from pain. Therefore, wind up occurs. And if wind up happens, then painful stimuli might be perceived as even more painful, and pain might be perceived even in areas that are not directly involved by the trauma.
And this is known as hyperalgesia. Remember, this can lead to chronic pain, and there is no way for an anaesthetized animal receiving surgery to protect itself from pain, so, i.e., move away, and therefore, no way to prevent windup from happening, unless we use preemptive multimodal analgesia.
So, as I said, pain is best managed early and aggressively. It is more difficult to control pain once it is well established than it is to manage pain before it becomes severe. So if you imagine that you have the twinge of a headache coming.
And you take paracetamol and ibuprofen immediately, that headache should completely disappear. But if you allow that headache, that twinge of a headache to then develop into a full-blown throbbing headache and then take paracetamol and ibuprofen, it's unlikely that you will completely eradicate that headache. So we must be, using pain, relief before it becomes severe, cause it is more difficult to treat it once it has.
So preventing pain should be the goal of the analgesia plan. Surgical pain is 100% predictable. If you take a scalpel to something, it will hurt.
So that plan needs to be in place prior to surgery. Now, the term preemptive analgesia obviously refers to the treatment of pain. Using analgesic drugs given before the introduction of a noxious stimulus and reducing the amount of no susceptive input to the spinal cord reduces peripheral and central sensitization and therefore also reduces perry and postoperative pain, which is a win for the practise, the animal and the patient and the owner.
So, the importance of preemptive analgesia, it lessens the intensity and duration of postoperative pain. It decreases the chance of the wind-up phenom phenomenon developing and therefore reduces the risk of a chronic pain state. And because the different receptors of the pain pathway are blocked before the introduction of a noxious stimuli, the pathway that pain travels on its way to perception is interrupted and pain is not experienced as intensely.
And I'm going to finish with an analogy. OK. Imagine that pain receptors are seats in a stadium.
All the seats are filled with home team fans, so the analgesics. An opposing team fan, the pain signal arrives and tries to find a seat. But because the home team fans have filled all of the seats, so the analgesics have filled the seats, the opposing team fans have nowhere to sit and therefore are unable to experience the game.
So In the same way, when preemptive analgesia is used, the pain receptors are filled with analgesics that block the pain signals from bombarding the dorsal horn neurons. Relieving pain, or what we often call rescue analgesia, relieving pain, as I said, is much more difficult than preventing it. Once a painful event is perceived, the pain signals begin bombarding the receptors, and the pain pathway is operating without any obstruction.
Analgesics must now block the receptors from receiving the signals and stop the bombardment. So if we continue with the above analogy, the stadium seats are now filled with opposing team fans, and the game has started. So the home team fans, the analgesics, looking, is looking for a seat, and they must convince an opposing team fan, the pain signal to give up their seat.
And as I said in our experience with a headache, if you treat it immediately. You are less likely to have a full blown headache. So, I hope that helps a little bit in, in, in, summarising how to prevent pain using preemptive and multimodal analgesia.
OK, summary. So besides patient welfare, there are many reasons why pain must be treated effectively. Surgical pain is 100% predictable.
If we use preemptive multimodal analgesia in our patients, this will help to prevent wind up from occurring. Use the Glasgow pain scales to objectively measure how painful your patients are, treat them, and then, check again and revise your analgesia plan as necessary. Temperature pulse, respiration and pain score, it really doesn't take much more time in your day at all.
And if you are in any doubt, if an animal is painful or not, then give analgesia, because what have you got to lose? Thank you very much for listening to me. I hope that's been helpful in some way.
And I look forward to speaking to you all again. Thank you.