So good evening everybody, and thank you very, very much for joining us for this evening's presentation, which has been presented by Chloe Fay, and she is going to be discussing the blocked cat. I am going to hand straight over to Chloe. If you have any questions for Chloe this, after the following the presentation, if you just want to pop them into the Q&A box at the bottom, and then we'll put them to Chloe at the end of the presentation.

Thank you. Over to you, Chloe. Thank you.

So tonight we're gonna talk about the blocked cat. I think quite a lot of us, probably all of us have seen a blocked cat, in our nursing careers. It is a common but treatable medical emergency.

So we're gonna go through a few things, a few pathophysiologies. So, urinary tract obstruction, basically is the blockage of flow of urine. So, it's as simple as that, urine is not gonna come out of these patients.

And we'll see this through different presentations which I'll go through in a couple of slides. But basically it can happen anywhere. It can be the ureters, so coming down from the kidneys.

It could be the blood, it could be something to do with the bladder, you know, and sometimes it can be stiff, you know, they can have, leakage from the bladder, and then things like the urethra. So mainly what we're gonna be talking about this evening is blockage to the urethra. And blockage, can be complete or partial.

And if they're left untreated, these obstructions can lead to acute kidney injury, necrosis or necrosis of the tissues of that whole area in that picture, especially the kidneys, tears, the tears in the urethra, ureters, urinary bladder, and even rupture. So this is how we end up with, your abdomens. So severely affected patients often present with hyperkalemia, post renal azotemia.

So when we think about the azotemia is pre-renal is before the kidneys post, it's after the kidneys, so the reason why it's post is this blockage after the kidneys. We get metabolic acidosis, as a result, and as a result of that, we get hypocalcemia, as well as this, we have dehydration and hypovolemia, which again, if left untreated, can progress to cardiovascular compromise. And so then we get electrolyte imbalances, and we really need to sort of fix this problem quickly because the electrolyte imbalances, the cardiovascular compromise.

The hypocalcemia, the metabolic acidosis gonna be the things that really kill this patient. Causes of urinary tract obstructions include things like an anatomic or physical, so things like urethral plugs, obstructive idiopathic urethras, urethalysis, so we can have this with or without bacterial infection, urethral strictures, which, I think I'm finding, we see more and more of, so whether this is breeding, . And then less frequently neoplasia.

So, it's very rare that you'll find that it's because of neoplasia, as well as if you functional, so urethral spasm this is another one that's quite common, and you'll note this if you've ever put a a urinary catheter into a patient. And they've spasmed against the catheter and this can just happen without a catheter being in there which obviously then stops the urine flow. And so this urethral plugs, so, they're often made up of inflammatory material, mucus, things like crystals, small stones, or calculi, that are formed in the kidneys and then passed through down into the bladder.

So again, these small stones, these calculi can get stuck in the ureter as well. So common risk factors, the cause of inflammatory materials and stone formation isn't well understood, but it is thought that viral infections and diet may play a role, so we know that these cats, you know, particularly ones on dry diets, on ones with high salt in them, and may play a role. So we'll go through a little bit more in that about revite and calcium oxalate formation as well.

Other causes reported such as cancer, so, and other things such as previous injury, causing scarring, so we know that those patients that have blocked once are more likely to block again, and often this might be because of, a place in the urinary catheter and potentially causing scarring, as well as trauma. So those RTA's, you know, with the fractured pelvis, you know, they may have torn urethras, . That may heal incorrectly.

So given the relatively long and narrow urethra, male cats are much more likely than female cats to develop obstruction. an early nutrient of cats doesn't cause reduction of urethral size as it does in some other species like dogs, so it is often that we see neuter cats to be at more risk of urethral obstruction. And this might be because those, cats are often heavier, and they, you know, if they're obese, you know, those cats might be indoors.

So there's a study done by Sega Etal, and they Determined that the mean age of cats with ruthral obstruction was around 2.5 to 3.5, mean, and that was significantly lower than gender match and time match, hospital admissions, for those without urethral obstruction, so around 5.5 to 6.5.

And in addition to that, they showed that cats that live indoors only weigh more and fed dry diets exclusively were more likely to be obstructed. So we know that we see a lot of these cats that they're indoor cats, they, they're heavy. They're often 6 kg plus.

They might be fed a dry diet. And often a stress event will trigger, this urethral obstruction for these patients. So the most common predisposing cause of feline urethral obstruction is urethral plugs and neural arthrosis, and so crystals and idiopathic cystitis.

And there are other factors such as muscle spasms and trauma, but what we're gonna talk about really is these urethral plugs and your thysis. So as a general whole, we have we call it feline or urinary tract disease. So it's a general term used to describe the conditions affecting the bladder or urethra of cats.

It's not a syndrome. So, specific conditions or specific syndromes within this, general term are feline idiopathic cystitis, neoiasis, crystal formation, urethral pros, urinary tract infection. Neoplasia, urethral strictures, trauma like I said with RTAs and pelvic fractures, and neurologic disorders, so reflex this is a dyergia, so it's basically the bladder and the brain don't talk to each other properly, so often they'll start urinating and then it'll stop for no reason, and even though there's still urine in the bladder and this can start to cause crystal formation and stone formation.

And behavioural disorders as well, so we know stressy cats, nervous cats, and anxious, you know, they may hold urine, and again, this is the same sort of . A factor that reflex is an energy. Your urolithiasis, and urinary stones are a common condition responsible for lower urinary tract disease in both dogs and cats.

So the formation of bladder stones, so calculi is associated with precipitation and crystal formation of a variety of minerals. So conditions that contribute to stone formation include a high concentration of salts in urine, so that's we talked about those high salt, like those really salty foods and soft in the just the ones that you can get in the supermarket rather than prescription diets. And the retention of these salts and crystals for a certain period of time in the urinary tract.

So again, if they're hole in the urine, you know, those cats that don't have multiple. Litter trays down, or they don't have anywhere to go in the house that they feel safe. They'll hold their bladder and so then they get these retention of these salts and crystals, an optimal pH that salts and crystallisation, a scaffold crystal crystal formation, and then a decrease in the body's natural inhibitors of crystal formation as well.

So basically everything just starts starts to fail and these crystals start to form. So high dietary intake of minerals and protein in association with highly concentrated urine may contribute to increased saturation of salts in the urine. So disease conditions such as bacterial infections in the urinary tract may also increase urine salt concentration.

So we often see a lot of these cats, you know, if we send off culture and sensitivity of their urine, they may have a bacterial infection often E. Coli. So in cats, approximately 4 to 5% of urine consist entirely or predominantly of strevite, and then most of these form in sterile urine.

So the pathophysiology isn't greatly understood but there are dietary and metabolic factors and so that results in an alkaline urine and increased concentrations of magnesium, ammonium, and phosphate, and these basically create the perfect . Environment for these salts like these crystals to form. So dietary factors, again, those diets high in magnesium, phosphorus, calcium, sodium, chloride, and fibre with a moderate protein con content have been associated with an increased risk as well.

So there's those are the greater ability to concentrate your room, . And therefore greater urine supersaturation may be partially responsible for urliformation in cats without urinary tract infections. So if they're, you know, concentrating in the urine, .

Really well, and then this is gonna again create another environment that's perfect for these crystals to form. Metabolic factors, so a formation of sterile streviureus may be twice as likely if you in pH is consistently elevated, so around 6.5 to 6.9 versus 6 to 6.2.

I'm sorry. I So often this creates an alkaline urine, and this is commonly affected by the diet, but it might be associated with drug therapy or renal tubular disorders. So those patients that already have like chronic kidney disease as well might be at more risk of stre bits.

So infection. So you write your list in cats potentially are associated with urinary tract infections, and that's because bacteria produce urries, bacteria such as Staphylococcus, . And in such cases, urea increases the ammonium concentrate in urine.

So, all of these things create a perfect environment for this rewrite crystals to form. And often we getting these is cats between 2 and 7 are at more risk for strevite and and apparently female cats have an increased risk for stre urehysis. Breeds specifically for stre white crystals that are at more risk of Burmese, Persian, Himalayan rex or the Asian breeds absinian, Russian blue, Burman and Siamese as well.

So again, Calcium oxalate is a little better, better understood and basically it involve involves the super saturation of urine with calcium and oxalate. So this happens via a few different ways. So again, we can increased dietary intake or endogenous production of oxalate may result in hyperoxalate urea.

So metabolism of vitamin C, glycine, g glyoxalate can increase production and excretion of oxalate as well. So these all end up in the urine, and, and then if there's a a high dietary intake, . Of calcium, or .

Enteric oxalate absorption may actually increase if there's a low calcium intake, so basically the body pulls calcium from elsewhere and then there's less oxalate in the gut is complex with calcium, so basically because they're not eating the calcium. I mean it's not forming the, the calcium oxalate within the guts, . It's start going through to the kidneys and I'm being excreted and forming in the urine.

So hypercalcia may result from overt hypercalcemia, so it might just be because they have idiopathic hypercalcemia or parathyroid adenocarcinoma. So, neoplasia may cause this hypercalcemia. And then because of that, if you have both hypercalcia and and hyperoxiaria, then you get these calcium oxalate crystallisation .

And then if we have these decreased concentration of these inhibitors, so so citrate and magnesium, they may contribute to this formation again as well. So, cats fed low sodium or low potassium diets, or diets formulated to maximate maximise your acidity are at increased risk. So use of acidifying diets has thought to play a role in this increase of calcium oxalate production.

So in addition, metabolic acidosis increases calcium mobilisation from the bone and contributes to hypercalcia as well. And so, those patients that ill for other reasons and have a metabolic acidosis and may be at risk of calcium oxalate, if they have all the other factors as well. So the risk factors often we find in older cats at age 12 years are most commonly affected by calcium oxalate ureuss.

And males most commonly develop these. So male domestic short-haired or medium haired and long-haired cats, are often found to be 1 to 4 times more likely to develop these calcium oxalate uruss and strerourus. And these purebreds that I mentioned on the last slide.

So the other thing I'm gonna talk about a little bit is . Urethral plugs, and they're possibly the most single common cause of urethral obstruction in cats. And, you know, often we will see the, crystal formation as well, but often the thing that's really blocking, those, those urethras are urethral plugs.

And these are made of either crystalline or cellular matrix. So they've had a high matrix content content over 50%. Within which mineral crystals, so things like strevites we just talked about calcium oxalates, white blood cells, red blood cells, so proteins, so mucus, and epithelial cells from the body become trapped and they basically just cause a little ball, and you might have seen these, they, you know, they kind of Sometimes they're sandy, sometimes they're like thick mucousy plugs, and, you know, they might be the tip of the penis, and sometimes they're a little bit further in, and that's why we have to flush and so thoroughly to get rid of all these materials.

So it's likely that in at least a proportion of these cases, the underlying causes idiopathic cystitis, so basically the blood becomes inflamed, and contributes to an increased secretion or leakage of various proteins into the urine, . And in a vast majority of cases, the crystalline component of the urethral plucks is true right, so if you put that urine under the microscope, and we're gonna see. I'm straight like crystals.

Which are the long coffin shapes and calcium oxalate are the nice little box shapes with the eggs in the middle. So let's go on to presenting signs. The most common early clinical signs of urethral obstruction are similar to, idiopathic cystitis.

So often what we'll get is a strangea. So, you know, there's constantly, trying to urinate often not, they might be doing it in, odd places in the house. And a lot of owners might, Confuses for constipation sometimes, you know, if they're not used to them, the cat looking like they're gonna go urinate.

As well as this, they might have dysuria again they're gonna have difficulty urinating, so they might be crying whilst they're trying to urinate. Hematurias, they might be passing small drops of blood. And so that's everything they might see with idiopathic cystitis.

Other things you might have is, all of your ear and aura, so a very, very small, so, less than 0.5 mils per kg per hour, or, you know, nothing, with anea. Unless, it's really important to ask the owners when you're triaging them on the phone or in a consult.

Is whether they've seen the cat urinate. Sometimes if they're outdoor cats, it's really hard for owners to assess whether these cats have urinated or not, and so often you're gonna have these other signs that we'll talk about now. So delayed unless specific signs that point to systemic involvement, and these are delayed because at this point your bladder is full, and you're getting these electrolyte changes, cardiovascular compromise is gonna be lethargy.

I'm vomiting and this is due to the onset of uremia, so because we've got that back up to the kidneys and we start to get that pre that post renal azotemia, which is gonna, and then uremia is added on to that, and we get it starts to make them feel sick and we get collapsed because of that, . And they might be anorexic as well. Other presenting signs that we might have again is painful vocalising, so they might be trying to vo they might be vocalising when they're trying to urinate, but they might also be just vocalising generally mutilation, so, you know, trying to bite or over groom the fur at the back, you know, licking or chewing their penis, .

And then other things like constipation, so constipation may also be there as well, but owners might say that the cat seems constipated when you speak to him on the phone. And then stylis, so there's excessive drooling and again this is due to uremia. So, the classic clinical exam findings that we're gonna find with these cats is this over distended turgid urinary bladder that can't be expressed.

So it's really hard, it's painful, so they are often even cats that are usually have a nice temperament and might turn around, might growl, might bite, and basically we're not able to express them, so it's a nice little diagram of . Expressing the bladder, but, especially with these, it's prudent to not squeeze too hard. And because we might be at risk of rupturing that bladder if it's very hard and and very full.

So other things that we might see, is that the penis might be reddened from the self trauma we talked about. You might be seeing a urethral plug, that is, protruding from the tip of the penis. But often what we're gonna see is the systemic signs of tachycardia, which may be due to, shock, so hypovolemic shock.

Bradycardia, to later stages, so this one might be when we have electrolyte abnormalities, so hyperkalemia. We might see, tachy mucous membranes, and then dehydration signs such as prolonged skin urgia, you know, sunken, eyes. Sene, so often due to the pain, and then high blood pressure as well, .

But they may, they may be normal intensive, so often other things we might find are pale mucous membranes and hypothermia, again due to shock, . And again, bradycardia can be a late sign of hypovolemic shock as well. So we might have an altermentation again because of this if we have high high levels of creatinine and urea uremia.

And like I say, we just need to be really careful about the abdo abdominal palpation just be really gentle with these casts just to avoid rupturing the bladder. So what are our main concerns with these patients? Well, acute kidney injury is gonna be our main one because we think that post renal lamia.

So it's a nice little 4 stages and often what we're gonna be seeing these patients in is stage 2 in this extension phase, so, they might already start to be getting to be having ischemia, hypoxia, inflammation cellular injury to those kidneys. And there's a really good, the Irish website is really good for, looking at the values. You can look at the creatinine values, and the other staging, things, but basically it's something to be aware of because once we get to these phases, we're gonna have to, you know, really provide these patients with fluid and support.

Electrolyte imbalances, so the most significant electrolyte imbalance in these patients is hyperkalemia, and that's due to its effects on the resting potential membrane, the resting membrane potential, of the myocardium. So we can then get these conduction abnormalities, so we get this loss of P wave, spike T waves, these white and bizarre complexes. And hyperkalemia occurs when the kidneys are unable to excrete potassium, and hydrogen ions as a result of drop in glono filtration rates.

So because we've got this obstruction, these kidneys stop filtering as much because they, you know, they can't pass any more urine there. Pain is gonna be another concern, you know, that is really hard. We know that these patients vocalised that you might be aggressive.

And so it's gonna be our main priority to get that pain relief on board. And again, your abdomen is gonna be high on our priority list for trying to prevent or being concerned about whether these patients have your abdomen, so we're gonna be looking for signs of sepsis or your abdomen, so and it's hypovolemia as well. So we just mention these, electrolytes a little bit.

So this blockage caused decreased kidney function. And we know that the loop of Henley primarily philtres. So this diagram is a nice little diagram showing that the, you know, sodium water, but as well as the potassium moves in and out of those, loops.

And basically if it's unable to filtrate an imbalance occurs, so. We get home And, a buildup of potassium, and hydrogen ions. And as a result, if we get an increase in hydrogen ions, we get this increase in pH, which leads to metabolic acidosis which can, you know, be a severe metabolic acidosis which we know might kill the patient.

So hyperkalemia, and the other electrolytes as well, we're gonna check, preferably on an epoch or handheld device, blood gas machine, but you can do them on your biochemistry, but if you're gonna do the epoch, it's just handy because you are a lifestyle. It's, you know, it's handy because then you can get your blood acid so you can decide whether the patient's got a metabolic acidosis as well that needs correcting with fluids, and ECGs as well. So we wanna check our ECG.

I'm Hi, so basically we get these tall spike T waves, widen QRS complexes and a lengthen PR intervals, flatten P waves, eventually they become non-existent and then we get this atrial standstill. As well as that, we might see ventricular fibrillation or asystole, so no heartbeat at all if we're looking at our lead to ECG. So we can get these hand, you know, the the cage side monitoring and we can use the surgery beds or, you know, anaesthetic monitoring equipment just to quickly pop them on.

Often fluids are gonna correct this hyperkalemia. And so as soon as you start giving these patients fluid bolus to correct shock, and then put them on a dehydration plan, and then once we unblock them, then essentially potassium's gonna come down, but what we want to do in the meantime is monitor with our ECGs. And just monitor signs as well, you know, whether these patients are collapsing and whether they have syncope, .

But otherwise, what we can do is there's a couple of things that we can do, often like the fluids are correct. We might give calcium glutinate to protect the myocardium so it doesn't actually bring the potassium down, but if you, potassium's quite high, you can give a dose of calcium gluconate. Which is gonna help that hypocalcemia if you have it, but also give the body a chance to get rid of that potassium and protect that heart whilst doing it.

Otherwise, we can give a bowls of glucose and basically what this does, is it drives potassium into the cells because the, there's insulin released to use up the glucose and this in turn drives potassium into the cell intracellular so that lowers your potassium. If that fails, we can do a concurrent insulin and glucose and CRI. So, these are just, an example of, these mild, moderate, and severe changes that we're gonna see.

So as I see in severe, so over 8 per litre, we're gonna see a loss of P wave, and we're gonna have these wide bizarre QRS complexes. For earlier on, we're gonna have these flattened P waves and the peaked T waves. Again, moderate loss of P wave belong to RS, ST segment elevation here, and we might have ectopic beats and escape rhythm, so there might be, beats that aren't associated with one another.

So the calcium glutinate, 10% is often administered 0.5 to 1 mL per kilo IV and it's so over 2 to 3 minutes and you need an ECG on these patients while you give that. So if the bradycardia worsens or you've got the QT interval shortening, then you should stop giving that.

So like I said, it doesn't reduce the hyperkalemia, and it is short-lived, it's 20 to 30 minutes, but basically, . It protects that myocardium, from the effects of the hyperkalemia, so hopefully we don't see or we see loss of these bizarre complexes. So I'm The IV dextrose, so a 50% solution to 1 mL per kilo, but we wanna dilute it to 10 or 10 to 20% because we don't want to give anything less than that peripherally because it can cause .

Phlebitis, and basically give us an IV Ebola, so, it stimulates this endogenous insulin release, and then causes intracellular translocation of plasma potassium, so the plasma potassium drives into the intracellular area. And basically gets rid of all the blood, . Other ways I'm at this insulin, so I'm one unit of regular insulin.

I'm. Basically speeds up this intracellular translocation process, but because of because of the effects of insulin, we don't want to give it without a concurrent dextrosepose so. Because otherwise we're gonna get this profound hypoglycemia.

And so often what this means is if we have these patients, we give them an insulin, we have to then have them on a dextrose infusion for a little while, so this can, you know, be costly to the owners and it can be more to monitor and so hopefully we try to avoid that and, you know, and just reach that dextrose first. Sodium bicarbonate, you can use, but, it's very rare because the risks of using it, you know, it can cause ionised hypercalcemia. So we've already potentially got these, hypercalcemia, and it, you know, it's quite risky.

I, to be honest, I've never used sodium bicarbonate, definitely not to drive down the hyper hyperkalemia, so. It's not something that we would regularly be reaching for. So first things first, these are things that we're gonna be looking at with our patients.

So the main thing with these patients is. Aggressive intravenous fluid therapy. so we want to replace shock deficits, so shock deficits where we want to replace within at least an hour.

I I've noticing that patient is in shock and then dehydration deficits, it depends on what you wanna do. You can do it every 24 hours or you can do it every 12 hours. I guess it depends on patient, you know, if it's an old cat that you suspect might.

Be at risk of a heart murmur or, you know, isn't gonna cope with that amount of fluid over 12 hours, you would do it over 24 hours. So it's just a nice little diagram on the side. So dehydration plus maintenance plus ongoing losses, is the amount of your replacement fluids needed.

So for a 5 kg cap, that's 5% dehydrated. So you do, your 5% as a decimal point, so 0.05.

And times by 1000. I'm And also times by 5. I'm sorry, that's a mistake on there.

I'm so do that now. That's 250 mLs. So we're gonna replace that over 12 hours.

So that's 20 mL per hour. So our maintenance load rate is 12 mL per hour, so that's because it's 60 mL per kg per day. And then we have a urine output, our ongoing losses, we want to consider after we've unblocked them.

It's 4 40 m over 4 hours, 10 mL per hour, so our fluid rate is gonna be 4 mils plus 20 plus . Oh, sorry, not 4 als, 20. 20 plus 12 + 10.

So it's 42 MPH, so that's quite a lot, so like I say, you might want to do it over, 24 hours, in which case we divide by 24, when you're working out your meals per hour. But a lot of these patients can handle that, especially when they get post-optructive diuresis which we'll talk about in a little bit. I'm, so yeah, fluids are really important and also I'm, you know, there's a, there's a bit of a myth.

I'm that I'm. You should wait until you've blocked cat, and we shouldn't administer a until we've dealt with the obstruction, and it's false a, and it can be detrimental. So basically, we want to improve that hypovolemia, correcting the metabolic acidosis and electrolyte imbalances, and often with these patients, we can get that fluid going, you know, we're not going to be leaving these patients for hours to unblock.

They're gonna be done, you know, as soon as you set up your equipment, but if you get your fluids going. You know, and get those shock boluses and and correct that hypovolemia, then that's gonna put your patient in a better position to be anaesthetized. I'm And we should be monitoring them, for signs of deterioration to pre-operative stages, and we can taper the fluids accordingly, but it definitely shouldn't be withheld.

I'm So other things that we're gonna be looking at as well is pain relief, so we want multi-modal, so we might start with a pure new opioids, so something like methadone. And then we might scale back once that patient is unblocked and a bit more comfortable, but initially we know those patients are gonna be very uncomfortable. We're gonna potentially, you know, we're doing a sedation or a heavy, heavy sedation or an anaesthetic, so we want to make sure that patient is as comfortable as possible for sticking a urinary catheter in there.

The use of coccygeal blocks, I love them, for blocked patients. It's gonna provide analgesia to the perineal region, for around one hour. So, epidurals and coccygeal blocks allow us to provide analgesia without affecting the motor function.

So local anaesthetic colo or combined with an opiates such as morphine, and we can use them to perform blocks in these regions. So we'll go through that in a second. But basically on a multimodal, so this local anaesthetic, as well as our, you know, given our patients opiates.

I'm. We might even use things such as GABA compounds, so things that affect neuropathic pain, so gabapentin, as well as NDMA antagonists, so things like ketamine. Especially in those first initial stages before we start blocking those patients.

We'll talk about a little bit later about anti-spasmodic spasmodics and sedatives might be considered part of your multi-modal plan to help. and also thinking about the types of urinary catheters. So if you've got a really tight fitting urinary catheters that might cause urethral spasms, and cause pain to that patient.

So really just thinking about what size urinary catheter we're using. We talked about using those ECGs to monitor for electrolyte abnormalities, and that's, you know, good to use in the pre, obstructive stages whilst we're unobstructing them, and often for, you know, an hour or so after we've unobstructed them and just make sure that those, we've not got any abnormalities. We want to avoid NSAIDs, so I metam meloxicam.

Especially in the initial stages because these patients often are hypolemic or dehydrated at the very least, and this is a huge risk to these patients to give them acute kidney injury, so we want to wait till these patients are appropriately, . Fluid replaced. So often it'll be, you know, after 24 hours at least, and before we start giving them, and we want to make sure that that pre-renal, that post, renal lasoenia is dissipated as well.

And because otherwise we're gonna be putting more pressure on those kidneys if we give them non-steroidals. So, I'm unlocking the urethral obstruction. I'm, we're gonna be doing heavy sedation or general anaesthetic.

It depends on costs and limitations to your owners. It depends on how well the cat responds to sedation. Often what we do in our clinic is .

We use, fentanyl or midazolam, but often, sorry, fentanyl or methadone, but often we give a 0.3 mg per kg dose of methadone. We'll give them 0.2 mg per kg of midazolam, and then we'll do a scruxygeal block, and that's often, really good.

Those patients are oxygenated throughout that, you know, we make sure there's no urethral spasms or any feeling in that area before we start placing. Urinary catheters, but you may want to general anaesthetic, you know, if not comfortable to take your blocks and heavy sedation probably isn't the right choice, because these patients can still feel that even though they're sedated. Something that I, if my bugbear is clipping the entire area, so I'm not just clipping, the penis.

You know, I do almost make them a baboon, but to be honest, because, we know that, you know, that, that area is potentially gonna get really dirty, and that's gonna have an indwelling catheter in there. And so we want to try and minimise the risk for bacterial translocation. So, clip the entire area as much as you can, really clean it, especially that bum, often we've got smelly bums, because what we're aiming for is sterility.

We're really aiming to treat that area as if it's, as if it's any other surgical procedure, and, you know, you would do an appropriate clip for. He next lap so that when you put your drape over, all you see is clipped area. And again, you would clean it the way you would in a surgical procedure, and drape it as well.

And that's something that also I don't see is I don't see people draping them. But, you know, that risk of fur, and debris getting in, is high, especially because our hands, you know, it's hard to avoid protracting the penis without touching. You know, the cat's leg, so if we've got a sterile drape on there and we use sterile gloves, we're keeping all the areas sterile.

So sacred geo block . This is actually a deceased animal, but again this is another procedure that should be sterile, so, . We should wear sterile gloves.

So basically we want to place the cat in sternal recumbency, as you can see here, and then palpate the space between the sacrum and the first coccygeal vertebra, and the, or the 1st and 2nd coccy. So what, what you often do is, I put my finger at the base of the spine and then lift the tail up and often you'll feel. You'll feel the gap, you know, and if you're not comfortable doing the first one, often you can get a bet to help you find that anatomy.

And then basically what we want to do is tip a clip a small square over the area and then aseptically prepare the skin. So we then should wear sterile gloves after we've prepped that, so again once we've got our sterile gloves on, we palpate the location of the most mobile joints, so moving that tail and and feeling that joint area. So, then once you do in cats, I would use an orange needle, .

To then penetrate on the midline, so down where the spine is. And basically, you insert it at a 30 to 45 degree angle. So often like a 45 degree, and then you advance through the interoculate, ligament.

And basically, it sounds disgusting, but you might hear a pop, when you go through that ligament. So it's not a bad sound, . And then basically as you advance a needle, there might be a little bit of resistance as you enter that epidural space and if you feel like you're scraping in your own bones, so .

You know, try, you know, bring the needle out, wait, and then try again. I'm So there's a little bit more in the notes with a step by step but basically unlike an epidural, like a dog where you would drop in and the . You would see an air bubble.

It's really difficult to see that in a cap. So, I would just, attach a syringe and aspirate just to confirm that there's no blood there. If there's blood there then I remove that, and then basically want to inject, .

Into that area, we just don't want to put any air in there either. So once it's completed, we withdraw the needle. Wait a couple of minutes and just make sure that tells relaxed.

You can test by basically poking the bumhole, and if it twitches then you've not done it right, . And just making sure that we don't overdose its low clinostat is making sure that you use less than 2 mes per cake of lidocaine. So, let's move on to unblocking the urethral obstruction.

So it's, it's dependent on preference, but oh, I'll go with the tear duct cannula first, just because it's nice and small, and often, as we've mentioned, there might be a urethral plug right in that penis. So, we know I'm gonna shove in a large catheter and often they're quite difficult to. Manipulate and flush, retrograde flush through a long catheter if you've only got a little bit in, in that urethra.

So if you get a, if you get a tear duct in and you manage to get that all the way in, and that's flushing, you do some retrograde flushing, and that seems to be going all right. Then you, then you can use your, Tomcat or slip or slam, to place in, because they've got the nice little wires, and basically flush lots to get the Urine clear. I mean there's no blood in there, there's no crystals, and hopefully.

So another tip is holding out, and towards you. So rather than, pushing, so if you push the foreskin back, . Often the penis will point upwards and towards the tail, but if you can manipulate that to basically go in a straight line.

Like parallel to the tail, then, then it's much easier to get a catheter in. And what we want to do is place a miler, or a soft flexible catheter for dwelling. So slippery sands and sometimes cats aren't, aren't suitable for indwelling catheters just because they're so rigid and they can cause damage to the bladder and to the, urethra.

So as you can see here, I attempted to put a tear catheter in, but it was really struggling. So I actually moved to a . Yellow catheter and with the starlight and and I managed to get a bit further and then we flushed it, removed that starlight and .

And then I'm then place a catheter but you can see I'm I'm holding it out in a straight line rather than pointing upwards. This was what came out of that cat after we placed, this is after we flushed it, and then, placed my look after. So you can see these are nice and flexible, and that means it's nice, it's nice on the cat when they move around.

And you know, they don't twist and get them. When they twist, they don't, I'm. I block off, and then they have these nice little yellow soft things that you can then .

Suture to the cat's prep use. And if you don't have that then you can finger trap sutures in and you just make sure, make sure that they're well sutured in, otherwise they're gonna fall out and you're gonna have problems. So, closed urinary, oh sorry, just to, to avoid trauma to the bladder mucosa, and catheter tangling, we shouldn't be inserting them in fully into the bladder, so we want to pre-measure them, to the level of the trigone, so.

I'm basically to like if you measure to like the weather, I'm. Where your pelvis is like the tip of the pelvis and the wing. So an in catheter, should be, secured with non absorbable suture.

So let's move on to closed system urine collection. So, a closed system should be used to prevent any ascending infection, and then we should only disconnect it, . When necessary, because it opens the risk of infection.

So we want to try and remain as sterile as possible. So we shouldn't flush them unless we absolutely have to. And when we empty them, we want to make sure that they're clamped off, and that we, I often will wipe using the sterile, sterile alcohol swabs to swab the, the tip, you know, that you pull out, and the urine comes out of once I've, once I've emptied the urine, I'll make sure I clean that properly.

So as well as that, we wanna hang them to allow them to flow, because otherwise we're gonna get, you know, often these patients aren't gonna pass urine. So we wanna make sure that we have got some, some form of elevation from patient to bag. Like I said, opening to flesh we should only be doing if we absolutely necessarily have to, and in which case we want to swap all areas, and make sure it's really clean.

As well as that, we want to check the penis, and the surrounding, and the area surrounding the catheter. So preferably every 4 hours when we're measuring our ins and outs, to avoid faecal contamination, urine scaling, so sometimes they leak urine around, as well as obstructions to the catheter, so like twists or patient interference if they managed to, you know, get the bus to colour off or if they rub it on their bed. So we wanna make sure it's nice and clean.

Again, just trying to make sure, you know, if you were treating an open wound, you wouldn't let it get dirty or full of, full of crap. You would, you'd clean it, so yeah, the same applies for us. So one huge thing that happens to this patient is post obstruction diuresis, so it's.

Frequently occurs with prolonged obstruction. And basically what happens is, they just start to put out a lot of, urine, so urine production exceeding 2 mL per kg per hour, and within 6 hours after the relief of the urinary obstruction. And a lot of these patients have this, you know, you can have it up to 72 hours following this, but often it will resolve if you correct it, .

And this is why we measure the ins and outs, so we don't get this hypovolemia, because it puts them at more risk of dehydration, you know, it might, change the BUN or the creatinine level, . You know, might cause an increase in aotemia if we don't correct that ins and outs. So basically we wanna administer a balanced electrolytic fluids, so we wanna give something like Hartman's, .

Rather than 0.9% saline, which I used to be sort of recommended, and we want to measure our ins and outs, so we're gonna be measuring what's going in with our fluids and what's coming out of our urinary catheter. So to measure the meals per hour, we do measured urine and divided by hours, divided by the kilo patient.

And like I said, normal is 1 to 2 mL per kilo per hour, but potentially post obstruction diariesis can have more of this. With I'm. With measuring the ends, if you have the use of pumps, what I would suggest you do.

Is every time you measure your ins and outs, instead of calculating how many hours that patient's been on for, and doing the same equation as this urine equation. I'm just guessing because you know the rate of the fluid, you know, say it's on 12 mLs an hour, . I'm I would zero your volume infused.

So does it, it'll take you through the options. You have your, you know, your meals, your time, your volume to be infused, and then your volume infused. Zero that because sometimes, you know, if a patient gets twisted or it's been in and out of the .

It's been in and out of the cage, you know, you've taken it off the fluids for whatever reason to go into another room to have it examined. It's not got 12 mL per hour, and you'll often find that, you know, say you did it over 2 hours and it was meant to be 24 mils, that it received, often it'll be something like 20 or 19. So, I think that really gives you a more accurate measure of your ins.

So, that is my top tip. So other things that we want to do as well is, consider the urine colours. So again, is there any blood?

Is it dark? You know, thinking about whether it's concentrated or dilute, but particularly if there's any blood and because we flush that bladder, or we should flush that bladder thoroughly, and, you know, there shouldn't be any blood, and if there is blood, is that because we've got a bladder issue, and you know, it might raise problems, so we might send urine off of culture. We want to measure specific gravity, so we might do that maybe twice a day.

You might do it every time you empty your bag. So normal specific gravity is around, 1.001 to just over 1.085 for cats, but often for like well hydrated individuals, it's usually 1.035 to around, 1.0.

060. So I'm And so basically what we want to look at is whether it's normal and often if we have urine that's concentrated over like 1, 1.035, and then this indicates a significant modification of the infiltrate.

And this might have happened because of active reabsorb reabsorbive processes in the renal tubules, so, . If there's azotemia in these patients as well as this concentrated urine, then it's gonna suggest that there's a large prerenal component to azotemia as well. So, as well as this post-renal, we might have a pre-renal problem as well going on.

And this might be because of your urethra block blockage. It might be due to chronic kidney disease or an acute kidney injury that was separate to, Of the primary problem in these patients. But basically, if this, if it aotemia, reverses on rehydrating these patients, and they have a, they still got concentrated urine, then often they're fine.

So yeah, we want to assess with the pre-renal sorry, post renal azote is correct and . So we want to make sure that that. BUN and creatinine is I'm correcting.

I'm, we talked about this dehydration deficit calculation. And then adding the maintenance as well. So, I'm pain scoring.

You know, Colorado pain score, they have the Glasgow modified pain score for cats now. I'm just making sure that everyone's on the same page, that everyone is, aware of how they're scoring. So on hand I was talking about those pain scores, rather than just letting the next person assume, you know, how you assess that cat, because sometimes it's behavioural, and then thinking about a multimodal pain relief.

So we might add in those NSAIDs once we. Have a hydrated patient and we're gonna, you know, use antispasmodics, and we might use sedation while they're in the clinic, and low dose sedation just to keep them calm or anzoolytics such as butrophenol. Blood pressure monitoring, so making sure that they're well profused, patient interference, so bus to call making sure these patients have best calls on from the very get-go.

So literally as they're, as you're recovering them, as you're waking them up, put them on, don't wait because a lot of these patients will wake up and potentially have midazolam, they can have a bad reaction when they wake up and . Rip that urinary catheter out on your back it's quite one. So, nutrition, whilst they're in the hospital, we don't really want to have them on specific prescription diets, but making sure they have wet foods, and making sure that they have big kennels, if you can.

Or the biggest kennel that you can that's a slight height because we know that having the food and water together can stress them out, you know, trying to put them in different areas and just making sure there's enough room for the patient to move around. We can put a little tray in there just so that they can . Go in it and when they need to, especially if they're starting to leak around that urine catheter .

As well as from consider additional fluids, so if we're tube feeding because of like a trauma and so that patient's been in an RTA, then. We wanna consider for tube feeding that is classed as liquids, so your ends are gonna be much larger or you might turn down your fluids because you've got those additional fluids going in via your esophageal or nasal esophageal and tubes. Urine scaling, so this big one, like I say, leakage around those catheters can often happen, especially towards, the end of their hospital stays, and so just make sure they're nice and clean, so make sure they're clean every 4 hours.

Faecal output again, we talked about that those patients being dehydrated, so they might have constipation as a result, so we might want to give them lactulose, we might need to give them enemas and to make them more comfortable and to make sure that urine, is able to be expelled. Anti-spasmodics are really important. This is stuff like umrazain which often we'll give to every cat because it's it's a hyperbase, which it functions as an alpha one antagonist, and so it causes smooth muscle relaxation.

So, so many muscles are located like a third of the penile urethra, so, they might not be effective in those with distal obstructions, but they're good for those I've got those little spasming penises, . So, like I said, 0.25 to what makes the cat, orally, every 8 to 12 hours if you can use easy pill or nice ways of getting pills, you know, trying to create a stress-free environment for these patients.

Anti antibiotics, antimicrobials aren't recommended really, unless a quantitative bacterial culture from your urine sample being sent off, demonstrates, a urinary tract infection so often like say staph or E. Coli, . So, because it's in dwelling, we want to try and avoid these antibiotics because it can, .

Basically, I'm causing increased risk for infection. I'm So those times. Should have it on urine they should within indwelling catheter you should have a culture sent off ideally and then another one after they've had the urine urinary catheter out as well.

So, a few tips and tricks. So, I like to use a sterilisation pouch to hold the urine collection bag. It makes everything seem a little bit cleaner and there's less risk for debris falling on it.

Like I, you know, I, I see the cat cat litter trays with the incontinent sheets in, and they're really good, . But, I just find the sterilisation patch much nicer because it covers that area, you know, where that urine comes out and we're gonna try and minimise our bacterial contamination. We wanna always send our urists away for analysis and see what's in them, but we can also look at our urine under microscope as well for streos, calcium oxalates, you know, epithelial cells and that kind of stuff as well.

Bigger kennels, cover the kennel as much as you can or give them little cat palaces, . They can hide him. Because we know these patients are often quite stressy, fairly way to reduce stress, minimal traffic through the cat board, you know, lights off and for periods of time, and noise off and, and, you know, classical music.

And as well as that flushing the style like catheters with sterile saline before placement, . It just makes sure that those catheters are patent and also you know, them are not flushing air that tends to not have bacteria, you know, if you've had it out on the table whilst we've been unblocking our cats, and it just reduces any bacterial contamination. And as I said, zeroing your volume infused on your drip pumps is a big one, in between your ins and outs, so you get an exact in.

So thank you very much for listening. I know I've been slightly over, if there's any questions, I'm happy to answer them now or I'm happy to answer them via email if, we haven't got time. I think we've got one here.

Yeah. Yeah. Wow, Chloe, that was, that was really, that was really, really informative and really in depth, complete coverage for the, for everything, all things blocked bladder.

So thank you very much for that. I've really enjoyed that. If anyone does have any questions, if you'd like to pop them into the question and answer box, and we can pop them over to Chloe now.

So we do have one, and then they have asked, when you put the cat on fluids, would you use saline or Hartman's? And do you worry about the tiny percentage of potassium in the Hartman's solution? So we would use Hartman's because it's a balanced electrolyte, solution, so it's most, like a component of blood.

So the problem with saline is, it's quite acidifying, and we know that these patients have metabolic acidosis, so we don't want to, make that worse. So the tiny percentage of potassium in heartmans is negligible, and especially, you know, we're gonna be. So, you know, we're gonna be flushing that, fluids through, and we're gonna empty that bladder, we can get that potassium down.

So that small amount of potassium in heartmons is fine because, you know, once these patients have been unblocked, we wanna make sure that they don't become hypokalemic. Yeah, absolutely, absolutely. We have another question saying, would you use Dantrium in your treatment plan?

Yeah, we often use Dantrium and Hypervise together. . I guess it's just on preference, but definitely anti-spasmodics, and then, yeah, Dantrium as well.

We often are pretty much in, I'd say probably 95% of our cases, we use tantrium. Absolutely. So, and then one more question.

Flushing the bladder, can you use warm saline, warmed up saline for that? Or again, do you recommend Hartman's? This is for flushing the bladder.

We just use saline, to be honest. . Yeah, she's warm saline.

And that's, you know, it's fine. I'm. Because we're gonna drain that out as well.

You know, we're not, we're not pushing all that saline into there and leaving it in there, we're obviously pulling it out. So, I tend to do, you know, 20 mLs a time flushing and then flush out just to make sure that's all coming out. And then another tip, is if you've had difficulty often passing it, what you might want to do before you wake the patient up, if you, if you're not putting an indwelling catheter in.

Is, . Is to put a little bit, you know, 20 mLs into the bladder and then, take the urinary catheter out, and then, you know, attempt to, express that bladder and just to make sure that that 20 mLs comes out by itself. Because otherwise you've got an issue and you probably need to put a urine catheter back in.

Yes. Now, another one, another question. How long after putting the cat onto fluids would you attempt to unblock the the bladder?

Like I say, often with ours, we wouldn't leave them for more than An hour depending on, you know, I mean, if that, if that bladder is hard and turgid and, you know, if that owner said that that cat's been like that all day, then you don't want to wait any longer. And so often what we'll do is we'll, you know, we'll be setting up to unblock it, you know, it takes 1015 minutes, you know, maybe they, we'll put them on, we put them on fluids before that. You know, and, and we'll just make sure, you know, sometimes if they, if you've got a severe metabolic acidosis or you've got a severe hyper hyperkalemia, we'll correct that with the fluids first and take another epoch, and then, you know, once that's a little bit more normalised, then we'll do it because like I say, it is gonna affect your risk of anaesthesia to these patients.

Yeah, absolutely. So that's the, that's the, that was the last question. So there's a comment coming through just to say thank you and that that that was really helpful and and informative and I will again I will second that, that was wonderful, Chloe.

So I'd like to, I'd like to thank Kyle from the webinar vet for doing all the stuff in the background for us. And I'd like to thank Chloe for a wonderful presentation this evening. I know I enjoyed it, and thank you everyone for joining us this evening.

So I'll let you all get back to your evening. Have a good one. Good night.