S1:E3 "I 'Kneed' To Know More (Nerve Blocks for Knee Surgery)"

Needless to say, you'll get a kick out of this podcast. I'm Amit Pawa. Eyepatch, genics, and cuties. Oh my. Today, pull back the curtain on knee blocks. 

I'm Jeff Gadsden. And this is block it like it's hot.

Yo. Yo. Yo. What up, doctor g? We're here to drop episode three. I told my daughters I wasn't gonna do that. How are you doing, Jeff? That's I love the rhyming so early on in the podcast episode. 

Excellent. How are you, man? Well, listen. It's happy New Year, man. How on line did you get me up so early to record this? 

Hey. New Year. New you. That's true. That's true. 

Absolutely. Now I'm I'm assuming you're recovering from some glamorous fancy bash last night, New Year's Eve? Well, let's just say my voice is is a little hoarse now. And by that, I don't mean the small four legged pony type thing. I mean, yeah, I mean, we had a big thank you. 

If that was a delayed joke, I thought you could leave me there hanging. No. We had a we had a we had a great party with some friends. I gotta give a shout out to these guys, the Souls Bees. They know who they are. 

We had a great party with them. And, I'm here this morning feeling ever so slightly sorry for myself. How about you, man? Yeah. We had a fun night. 

My oldest cooked us up a mess of chicken wings and this amazing peanut butter pie, and then we played some board games. So, yeah, tons of good food and lots of laughs with the fam. I love that. Do you have any New Year's resolutions? Oh, I think this you know, my my daughter Gigi got a tumbling this inflatable tumbling mat for Christmas. 

It's really cool, actually. She you can do cartwheels and Okay. All kinds of all kinds of stuff on it. And I realized very quickly when she was, like, dragging me into this thing how inflexible I am. So she's like, come on, dad. 

Show me the splits. And and I'm like, this is I you're you what you're seeing right now, Gigi, is me doing the splits. And she's like, that's just embarrassing. So I'm gonna I'm gonna get more flexible in 2023. In fact, my my my son Holt, who's also doing some gymnastic stuff, we have made a pact, and I'll state it publicly here that in 2023, we're gonna learn how to do backflips. 

Oh my goodness. Me. Yeah. So, you know, either I'll end up with a horrible injury and, or I will Holt and I will knock off the backflip challenge. That is that sounds pretty impressive. 

That sounds very impressive. We'll see. How about you? Any resolutions? Well, you know, one of them is to get is to get healthy, to make a, make some time and effort to get a bit more healthy. 

So I'm working on that. And the other one, which is a little bit more, lighthearted is, is to get better at remembering dad jokes. Now, we had some comments from Twitter about the fact that we didn't feature as many dad jokes as they thought, we might do. And one of the issues is I'm really terrible at remembering them, but, you know, I'm I'm gonna share one with you that is related to the pie one that I put out on the socials. Jeff, did you hear of the man who robbed a pie shop? 

He was put into custody. My god. It's all in the delivery. So Yeah. No. 

That was great. That was good. I like that. Custardy. Thank you. 

Thanks. What tell me you got a dad joke to go in in return to that. Come on. Okay. I actually I do have a pie related dad joke. 

Okay. What do they call a pie who goes to the gym? A buff pastry. Okay. That's great. 

I love that. I love that. Amazing. Yeah. How's your week been? 

Well, it's been it's been an interesting week. You know, I I had a PPI. I'm I'm sorry. A a what? Come on, Jeff. 

You must know. A PPI, it's a Peter Pointer injury. P p Peter Pointer injury. Oh, okay. Come on. 

You must have heard of that. You've heard of Pointer. Right? That wasn't where I was going with that, PPI. Lots of other things were going through my head. 

A proton pump inhibitor. Okay. But, you know, you I injured myself with a caps fill of omeprazole or or something. Right? What tell me about your your Peter Pointer. 

Well, listen. It's slightly embarrassing. I my Peter Pointer is, of course, my index finger. It comes from that song Peter Pointer, Peter Pointer, where are you? You know the song. 

Right? I do now. Okay. Well, anyway, I've used my Peter Pointer to open a door instead of using my full hand. I was holding something in the other hand, and as a as a result of that, I I I suffered a slight injury. 

But but don't worry. I'm okay now. Do you wanna block for that? That work. The PPI block. 

That sounds great. I don't know. I'm good. I'm good. I'm all good. 

I'm sorry to hear that, man. Did it stop you from sabering open a bottle of champagne last night? No. No. I was able to carry on functioning as normal just with slightly sore pee pee. 

Oh, slightly sore pee pee. Oh, no. Can we delete that? Episode. Can we delete that? 

Uh-oh. You should see a doctor for that. Yeah. Yeah. Okay. 

Moving on. Listen. I'll tell you why this week was cool for me. I bumped into the anesthetist with whom I performed my very first ever awake surgery under axillary brachial plexus block. He is a legend at Guy's and St. 

Thomas' called Leslie D'Souza. Wow. Wow. If that so that's really cool. If that was your first, that must have been ages ago. 

Tell me tell me who at least used a nerve simulator back then. Yes. You're quite right, Jeff. It was a long time ago, but I can go one better. No. 

We didn't use a nerve simulator. We used a sharp 23 gauge needle, two fifty cc syringes connected via a three way tap, and paresthesia. But I've gotta tell you what, man. That block worked a treat. It was my first foray to wake upper limb surgery, and I loved it. 

I owe doctor DeCesar a lot to get me into the into regional from that point of view, but that's not quite the way I do it nowadays. Ten to fifteen cc seems to suffice. That's I I I sometimes tell my trainees stories of how just how much local we used for inner scaling. You know, we we used 45 of local anesthetic. And I'll say, hey. 

Put put your hand on the side of your neck and feel what that feels like. Now imagine shoving two twenty mil syringes up there, and it's just the local went everywhere. We got every nerve in the neck. Sometimes both sides. I'm we I'm trying to think back. 

I I think some of my early interscalenes, even with ultrasound, actually, we were we were dropping in some large volumes. And actually now, when I look at when we where you're watching what you're delivering on ultrasound, there's no way you could deposit 40 cc's. I mean, I've literally run out of space by the time I get to my prime number of local anesthetic, but we'll we'll cover prime numbers on another episode. Okay. Sounds good. 

Well, you know, we've had some great questions and interaction online. I've I've been loving the comments on on the socials. Should we do some shout outs? Absolutely. Go go on, Jeff. 

Who's the first one from? I've been seeing lots of these comments coming through on our on our Yeah. YouTube and Twitter as well. So who's the first one from? So we had we had some comments about the Marmite of blocks, the ESP. 

Oh, yes. One from our friend, Amina Ben Yussef from Algeria. Hey, Amina. Hey, Amina. Who says that she's had amazing results with the ESP in nonsurgical applications like thoracic trauma and chronic pain. 

Says it also works great for for surgical indications, but that that was that's a good point with there's lots of in fact, the first ESP case report was in a chronic pain application if I'm if I'm remembering correctly. Yeah. That's right. Yeah. So great great to hear. 

Let's see. Here's an email we got from Diane in Arizona. Really enjoyed episode one. Now I'm trying to find a place to get a savory pie in Scottsdale. Okay. 

Well, good luck to you, Diane. I hope I hope let us know let us know if you do end up finding that savory pie. Savory pie. Did you have did you have any good mince pies over Christmas? Oh, man. 

I had so many mince pies. You don't wanna know. But I can't tell you where the best one was from because they were all mixed up into a big plate, so I couldn't tell who the the best manufacturer was. But we we pied out. We totally pied out. 

Ugh. We had some we had a whole bunch of homemade mince pies. Yeah. That was it was good. They're all gone now. 

They're all gone. But Diane says, can you talk about abdominal blocks and which one is best? I'm confused about QL versus TAP versus rectus sheath and several others. That's that's an excellent question, and I think we get we talk about this with our trainees a lot. You know? 

Mhmm. For what what abdominal incision do you use block a versus b versus c? And so, yeah, let's talk about we'll talk about that on a on a future episode. That'd be great episode. Yeah. 

Absolutely. And, you know, Jeff, we also got some comments about the presence or absence of apostrophes from Chris King, aka the Chris, one of my fellows who helped inspire us with this, getting this podcast up and running. Yeah. He dropped us in it with that apostrophe thing, man. Yeah. 

So yeah. You know, I was we we made the graphic for our thing, and and the the font that I chose to use for these sort of graffiti this didn't have apostrophes. So, yes, yes, we miss an apostrophe there, but thanks. Thanks, Chris. The Chris. 

The Chris. We will. Yeah. We just don't care about apostrophes. No. 

Now listen, Jeff. There's one more shout out that's just popped up that we must talk about. We've got a message from Kim Bayliss, and she's been following us on Twitter. And she asked us three questions. And I think we probably before we get stuck into the meat of the podcast, we've gotta talk about this. 

So the the questions are, what was the first block that you ever performed? What's your favorite block? And what's your most difficult to perform? Good questions. So what's the first block you ever performed? 

Yeah. Interscaling brachial plexus block. And I remember it because I made such a mess of this this block. I was probably a PGY. I was a second year trainee. 

Okay. And I'd never seen a nerve block before. I would you know, we're just doing sort of basic cases at that point. And then then one of my attendings, consultants, guy guy named Stan Herman. This is at Mount Sinai Hospital in Toronto. 

He says he says, I'm gonna show you a nerve block. And I I thought, man, this is gonna be good. I have not I've read about this. I haven't seen so he's like, alright. He gets everything set up for me, and I'm he's he's gonna do it. 

He's gonna show me how to show me how it's done. I'm just gonna sort of watch and help. He gets everything sort of sterilely prepped and draped and everything like that. And he says, hand me the needle. And I, with bare hands, pick up this needle, and I'm manhandling the the shaft of this needle and, like, completely contaminating it. 

And I I turn around, and he's like, that was our only needle in the hospital. So which seems odd now why we'd only have one needle. But, anyway, it so so we had to stop and, like, get a needle from across the street or something like that. But, yeah, that was my not a not an auspicious start to a regional career, but, why I did better. I did improve over time. 

Excellent. Well, listen. You I the funny thing is my first block was an interscaling two, and and I this is before ultrasound. This is with nerve simulator, and I was practicing the power multidirectional needle insertion technique in order to get some kind of recognizable twitch. I don't know what the acronym for that would be, But, yeah, I'd spent a lot of time moving the needle around to get the twitches, and it just and and then the my my consultant took over and just literally needle went through the skin first time, beautiful twitch. 

So I I realized at that point that I had to put some work at regional anesthesia if I wanted to get good at it. So that was my first. Nice. Jeff, what about your favorite block? I love a good popliteal sciatic block. 

Oh. The thing I love about it is when you get that spread inside the perineural sheath and then you, you know, you you see it sort of expanding up and you can tell, oh, there's the sheath. It's sort of surrounding the nerves. And then you do your victory lap as I call it. You sort of slide the probe down towards the knee and watch the nerves Mhmm. 

Separate it. Each each individual nerve has its own little owl eye of local anesthetic around it, and they come back up. It's it's a beautiful thing. No. It really is. 

Okay. I like that. Well, I it probably is not gonna come as any surprise to you that the paravertebral block or paraver what? Parrotibrol. How do you guys say it? 

Par paravertebral I I can't even say how you guys say it because I can only say paravertebral. The paravertebral block is my main accent. No. No. Perotebral, which is what LinkedIn translated it as. 

But, that is my favorite block, the paravertebral block. The king of blocks. Yeah. Hard hard to beat hard to beat a PvP. Yeah. 

And then lastly, Kim's question, what is the most difficult block? What do you find the most difficult block to perform? You know, I'm probably gonna get some heat for saying this, so feel free to roast me for this answer. But I I I find a tap block can be just frustratingly frustratingly challenging at times. And, you know, you you get a decent image, and then the needle comes in, and you're either too shallow and you're in internal oblique or you're too deep and you're in transversus. 

And I find myself going back and forth trying to establish that plane that just doesn't unzipper in a nice in a nice way. And so so I I have I have frustrating tap blocks sometimes. Well, I think, you know, I think the the truth could be said about many fascial plane blocks. Right? Because you're trying to open up that space. 

You're trying to split the fascia, get that classic unzippering. When you can't achieve that, it's very frustrating. And I think probably one of the best unzippering videos I have ever seen in my life is your supra inguinal fascia aliaka block that you did on the jute wrap. That is, like, beautiful to see that unzippering. So I I get why you you say a tap block might be difficult. 

You know the block that I sometimes struggle with? What's that? I sometimes struggle with quadratus lumborum blocks because sometimes just when I think I'm right there, I can't quite get the needles jetty right or open up that space, and I'm around the paranephric space. I'd yeah. I I don't think it's as easy as build. 

And then maybe I'm a little bit scared. I haven't quite we'll talk about this in our abdominal episode. I haven't quite ventured too much into the world of, of anterior quadratus lumborum blocks because I'm nervous about the whole thing. But I find QLs difficult sometimes. Yeah. 

Same. I I think, especially if you get a larger patient. Correct. So we, you know, we I live in the biscuit belt. It it it the many times we'll we'll say, you know what? 

Let's just not even try a QL for this patient. We'll do an ESP or something else instead. Okay, Jeff. Well, listen. We, you know, we procrastinated long enough. 

You know what I've called this episode. Right? I need to know more about knees. See what I did there? Oh, good one. 

So we we're gonna be talking about knees, and I kinda figured it'd be really great if we discuss the spectrum of things we can do for analgesia for total knee arthroplasty going from the minimalistic approach right the way through to the bespoke nuanced all singing, all dancing, Blocktober tastic twenty four injection approach. 24 and counting. Yeah. Let's do it. This is this is a supposed to be a thirty minute podcast or forty maybe. 

I I we don't have two hours to discuss all of but, no, this could be fun. Let's do this. Okay. Alright. So let me ask you a question. 

If you were having your knee replaced today, what would you want? Okay. So this answer will definitely have changed over the course of my career. So I think back to when I first started in in anesthetics, and I used to introduce myself as the baby SHO in anesthesia. You know, it was not unusual for patients to have an epidural for total knee replacement. 

And I used to see it was great to do an epidural. Patients would be comfortable. Sometimes we even gave them a GA as well as an epidural, and they wake up and they were comfortable. I've then seen that transition to a spinal and then GAs with a really hardcore femoral and sciatic nerve blocks, and those patients weren't feeling anything for at least twenty four to forty eight hours. And then I've seen general anesthesia with just local infiltration. 

And I can tell you for sure, and to answer your question, what I definitely don't want is just the general anesthesia with local infiltration because it's so variable. Right? Yeah. Yeah. Agree. 

So I think I would be cool with either a spinal or a GA, but the thing that I would definitely want to have part and parcel is I'd I want that twenty four injection multimodal approach with with some drugs and some nerve blocks, and and I'm cool with that. Even if I'm having, you know, a spinal as well, I want all of that in the mix. So I'm not I'm not that fast. Yeah. How about you? 

If I were to get a knee done today, I would want a spinal followed by eye pack, a Doctor Canal geniculars. Wow. Okay. So don't give anything else away here because what we want people to hang out for is at the end of the podcast, you're gonna give us that drop on exactly the process involved when a patient comes into your block room, and what you do for them. So effectively, you are saying you'd like to have done what you do for your patients. 

Right? Yeah. Of course. Okay. That's cool. 

Let's get into a bit more detail now. Assuming the patient is happy and there are no contraindications, does it really matter whether we give them a general anesthetic or a spinal anesthetic? Come on. Tell me what do you think about that. Yeah. 

I I think it it's interesting. That answer has probably changed a little bit too over time. I I think I was much more vociferous in my objection to GA earlier on in my career. I think the way we give GA is a little bit different than or it can be different than the way we Mhmm. Did in the past. 

And, course, with Teva and and LMA, it's, a healthy patient, it'd be hard to find an outcomes difference between that and a spinal. Of course, as you start to accumulate comorbidities and cardiopulmonary disease and that sort of thing, I think a spinal becomes much more attractive. And the reason our default is still a spinal is the early recovery period. It's just it's a softer landing. You know? 

So they they kinda come out of the the Teva sedation with propofol, and they're in the Recovery Room, and the legs are still a little bit numb and starting to wear off, and it's just a an easier transition to the rest of the recovery than than waking up wildly from a GA and going, oh my god. I didn't expect this. Okay. So the cup that's really interesting. There's a couple of things I wanna pick up on there. 

So the first of all, when I think back, there was I I agree with with you with regards to changing how forceful you were about trying to to push the spinal through. Because I remember the very early days when we gave a standard volatile anesthetic, and I used, you know, propylene induction, sevoflurane, maintenance, and I'd use morphine. I would and even if I didn't specifically do blocks because there was a group of our surgeons back then that didn't like us to do blocks. We give them a GA and opiates. My goodness me. 

Those patients woke up, and they would not they you know, they wake up exactly as you say. They they didn't wake up going, oh, lovely. They woke up, and they were sore immediately. That's the first thing they remember being was sore. You know, I was having to give them a fair amount of morphine on the table to deal with some of the tourniquet discomfort and then the knife to skin. 

So that experience wasn't that great. And when you compare that with the patient having a spinal anesthetic, I'm not talking about their post op recovery. I'm talking about the immediate PACU arrival. They were so much nicer. Right? 

They they they emerge from their sedation if they'd had sedation, and they look so much more comfortable. If I look at my general anesthetic now, I tend to use TU. I've moved nearly exclusively onto profol and remifentanil based general anesthesia. So that means that intraoperative course is much smoother. And then we'll talk about this in a short while, but when you're using the blocks, the wake up is is less aggressive. 

It's a little bit more subtle. And there's a few other things I was gonna cover in a short while that that may have helped that. So I think my GAs from a while ago compared to my GAs now were very different. So I think in a straightforward ASA one fit and healthy patient, I'm less forceful about pushing a spinal now, especially when we've done the unicompartmental knee replacements. Actually, I found if I give them a light GA and I do some blocks, they they seem to be ready to rock and roll. 

I'm not worried so much regarding their pain afterwards. Now that leads us very nicely onto if you have to choose analgesia versus mobility. So we can make a patient completely pain free, or we can give them the ability to mobilize with pain. What do you think is important? How should we factor, those those two variables? 

That's an interesting question because, you know, back in the early days of my career, we used to have this conversation with the physical therapists and surgeons about about this exact point. And their perspective was, oh, well, you you shouldn't do a block because we want them up and moving as soon as possible. And our pushback to that was if patients are comfortable, even if there's some degree of motor impairment of the quadriceps with a femoral catheter, for example, they will walk faster and walk ultimately and better. The comfortable patients meet their rehab goals faster. So were you mobilizing patients with femoral nerve catheters? 

We were, but and, of course, you have to do it in a safe way and with some assistance and and someone standing standing beside them with a, you know, there's a walker or a guardrail or something like that. But we don't use a lot of femoral blocks for for knees just be because we have other motor sparing options. Mhmm. But I think what's what's been lost is this idea that you can give someone femoral block and have some quads weakness, and they can still get up and move. Okay. 

Cool. So I think that's kind of answered my my viewpoint on that. The next thing I wanted to ask you about was, does it make a difference whether we use short acting or ambulatory spinal anesthesia medications or whether we use standard intrathecal medications like bupivacaine? You know, we don't have easy access to the short acting intrathecal medications, but should I make a move to get hold of them? So, first of all, why do words sound sexier in a British accent than they do in in America? 

Ambulatory. I'm gonna start to say, ambulatory. Sir, I'm gonna give you an ambulatory spinal. Oh my god. Okay. 

Controversy. Okay. There's some controversy about the ambulatory spinal. Just don't put a tube in my trachea. That sound better than trachea, though it does. 

I have to be yeah. Yeah. Yeah. You're not wrong. So we've we've gone through this evolution in the past several years of moving away from bupivacaine spinals Uh-huh. 

To a shorter acting agent. And the whole reason is because while some of them do wear off in sort of two or three hours, there are a cohort of patients with a bupivacaine spinal that will have a sensory or sympathetic block out to like six, seven, eight, nine hours and they're just we're getting orthostasis and they couldn't get up and move and we're being admitted overnight when they should have been going home. So so now we're using a a shorter acting agent, mepivacaine, and wait for it, lidocaine. What shut the back door? Did you say lidocaine? 

I did. I did. Yeah. Spinal? So what about TNS, man? 

I know. Handcuff me. That was our concern too. And, you know, because we had this pounded into us as trainees is that, you know, lidocaine equals TNS. We have other options. 

Don't use lidocaine for spinals. That message is still being taught to trainees because when I suggest lidocaine to someone who hasn't been on the block rotation yet, they're like, wait. We're are are we allowed to do that? Kind of thing. So well, and I don't want to give too much away, but, one of our fellows will be presenting some of our data at the I'm give a shout out here to the ASRA spring meeting in April 2023 in Hollywood, Florida. 

So hope to see you there. But we've collected some data over the last year and a half of doing this lidocaine spinal business, and we've had an an incidence of essentially zero TNS. Okay. That's very cool. And I I I definitely look forward to hearing about that. 

Yeah. It does sort of fly in the face of what we were taught about TNS and the risk and and that sort of thing. And I think the reason we're not getting it is because we're so good at multimodal. So Mhmm. All these patients are getting acetaminophen or paracetamol. 

They're getting NSAIDs. They're getting dexamethasone. They're getting ketamine. Now hold on a minute. Hold on. 

I'm gonna I'm gonna stop you there. So I had a thought about this. You were talking about some of the standard bupivacaine spinals lasting longer, or having a sympathectomy that that that hang out. Now I I heard something discussed at one of the ESRA meeting or the ESRA meeting in or last year, and they were talking about dexamethasone prolonging the effect of a spinal. And had it occurred to you that perhaps administering intravenous amethasone to these patients having intrathecal medications or spinal anesthesia may have contributed to those prolonged spinal actions? 

Interesting I've never considered that. No. I I just wonder whether that's something that may be relevant. Yeah. I it's a that's a good question. 

Although we do we still give it intravenously to our lidocaine spinal patients, and they I don't have that one. No. I mean, those spinals will last a hundred and twenty minutes point zero. So you have to you have to have the workflow and a quick surgeon, etcetera, etcetera. So if it's a revision total hip or tonal knee, we're gonna choose something else typically. 

That's one of the things that does make me a little bit nervous about using ambulatory spinal anesthesia is that you've gotta get your timing spot on. Communication's gotta be key. You gotta get a patient in, block the sends, gotta be ready. And if there's any delay to that process, that's what that's what gives me the, the heebie jeebies as we would say over here in The UK. So okay. 

So I think we we we posted some thoughts out there for people to to come back at us with. I'd love to hear what people's experiences on whether they're using. I'm gonna move on to, another topic, which I do think is controversial because a lot of the, the guidelines and pathways that are suggested now are telling us to not bother putting in intrathecal opioids. Of course, in The UK, we have or we at least certainly recently had ready access to to intrathecal dimorphine, and I know, other people using things like morphine. I don't think it's a massive deal to put opioids in the spinal, but but I know you're gonna tell me that it is. 

So what are your thoughts on intrathecal opioids? Well, for starters, it diamorphine. Right? So if I if I said to one of my patients, ma'am, I'm gonna put some heroin into your spinal today. That would not be received very it's not a it's not a popular thing here, I think. 

It and certainly, we don't do it in our practice, and I I would tend to think that in most orthopedic practices in this country, we we don't. Just because of the side effect profile. So, you know, you Okay. Pruritus and delayed urinary retention and and, you know, possibly respiratory depression. You know, the multimodal the other multimodal agents are and, of course, all the 27 nerve blocks that we're doing. 

Yeah. Really, really help to to control the pain without having to pull that lever. Yeah. I have to do this. There have been some situations where I think I think having that benefit of a slightly prolonged action from intrathecal opioids is beneficial to us. 

I I'm I'm not somebody who's totally against it, but, you know, maybe maybe they just haven't done the sheer volume. But one thing I I wanted to ask is, you know, if the catheterization risk is significant in patients receiving spinal anesthesia such as those over a certain age or, you know, with with enlarged prostates, in those groups, you know, wouldn't you just give them a GA rather than run the risk that they may require catheterization or the risks associated with infections afterwards. It's a good thought. It but interesting. One of the things that we've realized having switched from bupivacaine to lidocaine or mepivacaine is that our rate of straight cathing patients in the PACU has dropped significantly. 

By using a by using a short acting spinal medication? Okay. Do you deliver the same peripheral regional anesthesia irrespective of whether the patient receives a spinal anesthetic or a general anesthetic? Yeah. I do. 

So whether they're getting a spinal or a GA, we still do the same blocks. Yeah. Okay, Jeff. I have a confession. I'm not sure if you're ready for this. 

So Power's confessions. Yes. Everyone sit down, grab a cup of coffee. Don't judge me. So when I'm doing a spinal anesthetic, I know that the patients are gonna be comfortable for that immediate postoperative period in recovery. 

So I do a spinal anesthetic plus some of the injections that we're gonna talk about in a second. Now when I do a general anesthetic, even though I'm adding in those extra peripheral regional anesthetic blocks, maybe not quite as many as a twenty four point block tastic approach. But even though I'm when I'm adding those things in, I don't get the same smooth, beautiful emergence that my spinal patients have if they when they're emerging from sedation. So I have taken to doing, get ready for it, a lidocaine femoral nerve block. Now this was inspired by one of my colleagues at Cleveland Clinic London, chap, very experienced regional anesthetist called Ravi Naya. 

And he he's he told me he did this. And, actually, since I started doing a lidocaine femoral nerve block for my GA patients having these multimodal analgesia and these peripheral blocks, they actually wake up so much nicer. What do you think about that? Do you wanna hear something crazy? I do the same thing. 

What? The same thing. Yeah. This is like a scene of frozen jinx jinx again. Okay. 

No. Don't get me started. You do the same thing? Yeah. For because I just feel I do feel so bad for these patients that are waking up so acutely with and having to experience all that nociception all at once. 

So and and, of course, the whole reason we got away from femorals was we don't wanna prolong the quadriceps weakness into the, you know, day one, day two, day three, but a quick little lidocaine femoral smooths out that early recovery period. We're not really hampering their recovery all that much because it's such a short acting block. Well, I'm fascinated to hear that because, you know, what was interesting is when I have been doing this, let's just say the operation has taken an hour and a half, you know, just under two hours for, you know, all things considered. And I'm only using such a low volume of lidocaine. Or by the time I see them in recovery, they've got some, some hip flexion. 

They're doing some of the things you'd you'd want them to be able to do, actually, and they don't have the pain. So how fascinating. Okay. Well, you heard it here first, guys. Lidocaine femorals. 

The other use case for that that I've employed is once in a while, I'll get a patient with you, doctor Kanal, block or catheter, whatever you've done, in the recovery room who's got just rip roaring quad spasm because of the surgery. And, of course, our adductor is not doing anything about that. So I'll just hit them with a very low dose lidocaine femoral block and boom, the spasm goes away. So let's just imagine. So we're working on the premise, and and I'm working our way down the all of the different injections that we're gonna do. 

We work on the premise that people have got loads of time to do blocks. And, actually, that maybe doesn't reflect anesthesia practice all over the world. So if an anesthesia practitioner had limited time and or, you know, a limited experience, what do you think is the minimum peripheral regional anesthesia technique they should employ when delivering, you know, care for a patient for total knee arthroplasty? I think minimum is a doctor canal, and then anything on top of that will add additional value. I don't know. 

How do you feel about that? Well, I agree. But now it's almost as if you knew what I was gonna ask you next because this kind of segues quite nicely into I wanna talk so when you say a duct canal, do you mean what most people talk about when they talk about adductor canal, which is actually a block at the mid thigh, which potentially is the at the apex of the femoral triangle, or are you talking about an adductor canal at the adductor canal? So I think this is where, unfortunately, we've kind of made life a bit difficult for us with regional anesthesia in in getting complicated. So when you say Dutch Canal, what do you mean? 

Are you suggesting we have a nomenclature controversy? I think we do have a nomenclature controversy so much so that I think we're gonna dedicate a whole episode to this. But but but yeah. I I am. So what do you mean when you say that? 

Yeah. I know. I this this debate annoys me. I we're I think we're all doing the same thing. We're all doing it at the mid thigh. 

So, technically, probably, yes. Femoral triangle, are we ever gonna get away from the the name adductor canal even though I know I know it's not technically in the hunter's canal down by the knee? No. I think they were gonna keep keep calling it that. So I think we're probably doing the same thing. 

Yeah. What we do is is mid thigh, so it's technically in the femoral triangle. Okay. So here's the here's the the thing that I think has caused some confusion amongst some very experienced regional anesthetists. So I practiced my femoral triangle slash adduct canal blocks based upon the learnings from the papers and and what I've got from the Blocktober videos. 

And you make a a specific point about educating us about the how to make sure you specifically get the nerve to fastus medialis. There are some very experienced practitioners that would say, well, actually, you don't want to block the nerve to vastus medialis because that will contribute to more of a motor block. So what what do you think? Do we need to get nerve to vastus medialis? I know what the answer is, I want you to explain to me why. 

Yeah. Oh, no. The answer is definitely yes. I mean, I've when we started deliberately targeting that and getting local around it, our pain scores went down on day zero and day one. So so it it is an an important part of that technique. 

But your question is a good one because it, of course, it is a nerve that innervates a muscle. And so the question is how much at the mid thigh, how many of the motor branches have already come off? And are you are you not getting those motor branches? And so one day in the block area and how many stories I'm gonna tell start with one day in the block area? We were talking about this question and decided to think about a way that we could test this. 

And so by blocking ourselves at different this. Different points along so starting at mid thigh Uh-huh. So exactly midway between the inguinal crease and the patella Uh-huh. And then and then going up at sort of gradation wise up towards the the inguinal crease. And it and and we did this very scientific we did this quasi scientifically. 

We had a force dynamometer, so we're measuring quadriceps strength. And it was the intent was to answer the question, how close do you have to be to the inguinal crease before you truly get, like, quads weakness? And, it was with a view towards doing a much more rigorous actual study in in volunteers later on. But so I can tell you that the ant quick answer was you have to be really close Okay. To the inguinal crease before you get a profound quads weakness. 

And I can tell you from them, quads weakness is real. It's a real thing when you finally do get there. But, anyway, don't try this at home. Okay. I think I think our I think our our podcast should probably just come with a blanket. 

Don't don't try this at home. But it was so we'll we'll we're getting around to doing that actual study when in volunteers in a in a rigorous way, but the cadaver evidence and when I talk to anatomists, they also reinforce the idea that at mid thigh, any motor weakness you might get from getting that nerve to vasa medialis is minimal because a lot of those motor fibers have come off already. I wonder whether tourniquet has an impact on that, in terms of proximal spread, but that's that's interesting. So it's it's nice to see that you've noticed that your pain scores dropped once you well, you made sure you added that in. So that's that's reason that's good enough for me. 

Okay. So we started off with our minimum. Now let's add something in. So let's say we're gonna add in the iPAC. How important do you think the I pack is, especially in the context where your surgeons may want to do their posterior infiltration themselves? 

Do you think it makes a difference? Because I've got some some of my surgical colleagues who are very keen to do that. We've started in adding in the iPAC as well, but it can be a bit of a a bit of a faff to do it. And I and I think you'll you'll talk to us about how you adapt to doing that, but I find sometimes doing an iPAC with the patient in the supine position, do I frog leg the the knee? Do I go for underneath? 

Do I I mean, it's it's all a bit fiddly. But how important do think the eye pack is? I first of all, is Pfaff spelled with a silent p? No. Or is it is it f a? 

Well, I spell it f a f f. And, you know The Germanic spelling is more like the f f. Yeah. No. No. 

No. I I don't think it's I don't think it's a silent p. I mean, they always say, Amit's faffing about in the anesthetic room, that's where I'm used to hearing it. But yeah. It. 

I think the iPAC is if you had a gun to my head, so Jeff, you have to drop one of the blocks that you do, iPAC would be the one. Now having said that, I don't think it's without value. We have looked at patient recovery profiles in terms of how far they can walk afterwards. Uh-huh. And it and it and it looks like if you get an eye pack versus getting a saline eye pack, you can walk farther on post op day one. 

But if you were gonna drop but if you were gonna drop something, that might be what you dropped. That may be the one. Okay. But but my question back to you or maybe back to your surgeons is, like, why would they want to do that? Why would they want to infiltrate behind? 

Because we I've got I've got ultrasound guidance. I can see the popliteal artery. I can see the sciatic nerve. I can see all the stuff I don't want to hit. You can't. 

You're injecting through the capsule. Why would you not wanna leave the analgesia to us, to the experts? It's a fabulous question, and I don't want to upset or offend any of my friends and my surgical colleagues by by saying anything that might be, might be misinterpreted. But I think there's an element of they were trained to do it a certain way, and that's part of their training, that's what they're supposed to deliver. And they'll come to meetings, and they hear about how their colleagues in hospital x, y, and zed do it a certain way. 

And then and they say, what about you? They say, well, actually, I don't do anything because my niece just faffs around in the anaesthetic room and does it all for me. I wonder whether they there's an element that they want to do. I don't know. But I think, actually, the conversation is changing because when we first started, certainly, my institution, we weren't doing blocks for knees. 

And over time, as a bit of understanding has come in, and we talked about the motor sparing component, that has changed. So I don't know why they'd wanna do it, but I think with time, it may be that it falls under our control again. And, you know, listen, we're all looking after patients jointly, but I agree. If you could do some kind of direct vision as opposed to inject, and then they wash the knee. They inject local ants, and then they do this jet wash. 

And then where does the local go? So I I have some questions myself. So I wanna move on, Jeff. So now we're getting on to probably injection seven and eight of the twenty four injection technique. I'm gonna stop I'm gonna stop reviewing you about this because I love it, actually. 

So I'm talking about the geniculate. So in, in your teachings before, you've talked about, the supramedial, the inframedial, the supralateral, and the nerve to, vastus intermedius. You initially talked about dropping, the infrolateral genicular nerve block, which I must confess I've done a couple of times. What value do adding the genicular nerve blocks do when you're already doing a femoral triangle block plus or minus an IPAC? How do they make a big difference? 

So a great question. And we we did a randomized control trial a couple of years ago led by our one of our fellows, Millie Rambia, who and showing that if you do the adductor and the IPAC and then add on those three genicular blocks, inferomedial, superior medial, superior lateral with quarter percent bupivacaine versus saline sham blocks, you get a 60% reduction in your twenty four hour opioids in the first twenty four hours and then an additional reduction in the second twenty four hours. So it is a it's an easy, impactful intervention that that packs a lot of punch. So I do like genicators. I think that clearly, once my understanding of the anatomy became more sort of robust and I realized, you know what? 

A lot of that knee capsule is innervated by genicators, and we're just not getting with our adductor and eye pack. It became an obvious target. Listen. I'm sold now. And I'm sold for a couple of reasons. 

Number one, by your by your scientific argument then, you and your evidence of what you've seen in clinical practice. But number two, because I made a small modification. So I am most of my fellows will know that I'm a massive proponent of in plane peripheral regional anesthesia, and I used do all my blocks within plane. But you know what? What should have been the quickest part of my regional anesthesia recipe for the arthroplasty's reticulars, I was messing around for much longer than I should have been trying to do these in plane blocks. 

Bearing in mind, I'm trying to do a block around a curved surface of the bone, and I I found I was definitely faffing around a lot. And the one modification I added was doing out of plane geniculars and boom. It suddenly dropped my time. So, actually, now my fellows were were laughing. They're like, you do in plane for everything else. 

Now why all of a sudden are you doing out of plane? It you know, it was a suggestion that you you gave, and, actually, it made such a big difference. So I think now, once I've done my my eye pack and my my femoral triangle block, adding in the outer plane geniculars has made a massive difference in my practice in terms of speed and certainly outcome as well. Yeah. Yeah. 

We find the same thing. And, any block where you're hitting a bone as your end as your end point for needle advancement is just easy. But that out of plane really makes a difference. What what I would we were finding when we first started doing these in plane is rather than trying to line up two things, beam and needle, now you're asking to line up beam, needle, and femur. And that just became so complicated. 

Any slight shift in the probe, you lost your image. So I I I agree. Out of plane is the way to go. Now tell me, have you added in the infrolateral genicular nerve block? Well, it's interesting you say that because yeah. 

When I first started reading about genicular blocks, all the stuff came from the chronic pain world. And I think they're feeling and advocacy about omitting the inferolateral came from radiofrequency ablation and neurolytic blocks and that sort of thing. And gosh, you wouldn't want to knock out the comaparoneal because it's so close. But I began to think, you know what, man? I I'm using ultrasound, and I'm only using a little bit of, you know, a few mils of local anesthetic. 

Is it really a risk? And so we've added I've I've added that back into my to my mix since. And just just, forgive my, anatomical, lapse in, knowledge here. I've just got to remind myself, when you're doing your infralateral geniculate nerve block, which we're not advocating everybody does because of the risks associated with are you blocking it on the lateral the infralateral aspect of the tibia or the fibula? My recollection is you're doing it on the tibia. 

Yeah. That's right. Yeah. So just on the on the lateral aspect of that proximal tibia. So, actually, again, this this sort of if you do with ultrasound, you should be so far away from the common perineal nerve that that actually we should be blocking it if you're doing that small isolated volume. 

But I I still understand why you want to exercise caution because it would be a disaster if there suddenly were a whole host of patients presented with foot drops because of this Gadsden induced technique. Right? We would hear about it for sure. And and we have it. So yeah. 

So it seems to be fine with that that, you know, three, four mils of volume and on that lateral aspect of the of the tibia. Okay. I've got two more questions, before we get to the Ganston recipe. So I hear a lot of people talking about when they're scanning, looking for a duct canal and femoral triangle, They're also looking over the, the surface of the sartorius muscle, looking for the anterior femoral cutaneous nerve. And they talk about just popping a little bit of local anesthetic above the fat below the fascia, above the muscle. 

Is there a value in that? You know, we're talking about the geniculars. We're now talking about an additional genicular that we weren't doing before. We're talking about the nerve to vastus intermedius. Do we need to do the antifemoral cutaneous nerve as well? 

So I am somewhat reluctant to get I get some pushback sometimes about, like, adding yet another block. Uh-huh. But, yes, the answer is yes. We we are I've started to do the the anterior femoral cutaneous nerves. These cutaneous nerves or or cuties as we call them Uh-huh. 

Seem to be pretty important actually. And and and they're really fun. I start at the medial edge of the sartorius, and you can see in that layer of fat just above the deep fascia of the thighs, usually two or three little raspberries hanging out there, and it's easy really easy to to drop in, you know, two or three mils of whatever remainder of local you have in your syringe on the on those. So you'll you'll be shocked to know that I blocked myself Oh my goodness. One day. 

They well, I I was curious because I I heard about people using cryoablation of these for total knees. I'm I'm my instinct was like, man. Come on. These are cutaneous nerves. Yes. 

How much could this contribute? So I took an a nerve block needle with a nerve stem, which was really interesting because as you get close to them, you get this little paresthesia in the territory that they serve. So Okay. You could you could feel it kinda going down to your knee, and each different one had a slightly different pattern of innervation. I put a few mils of quarter percent BP on these at 4PM. 

It sure enough had like this densely numb anterior thigh and down to including including the kneecap, and went home that day and, you know, went to bed, and I had to explain to my wife why I had I had these poke holes all over my thigh, which she's used to it by this point. You know, this is always something. I woke up the next morning and I had kinda forgotten about it. Right? Get out of bed, I'm like, oh, wow. 

My thigh is still densely numb. Like, could Wow. Take pliers and I didn't. But you could have taken pliers and, like, cranked on that skin and nothing. And it lasted till 2PM. 

So I had twenty two hours of really dense skin numbness on the thigh and kneecap. And I thought to my I'm thinking to myself, man, that has to have some value. Just, I mean, just for incisional pain alone, but super easy to do and safe. You're not gonna you know, there's no motor stuff there. So And what level what level of the thigh are you doing this? 

There have been different descriptions. And, Thomas Benson's group out of out of Denmark, I was talking to him at the Ezra meeting in in Greece this past summer Yes. And he is convinced that there is much more to cutaneous innervation in terms of what it provides. And I I tend to agree with him. So he's got a a slightly different way of doing it, but I I just go mid thigh and, and look for those little cuties in the, subcutaneous fat. 

Okay. Well, well, I, that's something that's something to watch for. Hashtag block those cuties. Brilliant. Okay. 

Listen. One more one more question before one more topic, really, before we move on to, the Gadsden, gold standard arthroplasty approach, which is I'd heard somebody and I I'm trying to work out whether it was Thomas Benson's group from Denmark or who it was talking about doing a isolated tibial nerve block instead of an IPAC for posterior knee pain. And, certainly, if I recall correctly, there was a study where they had a whole host of patients who maybe had, femoral triangle or duct canal blocks. And in the PACU, they added in an isolated tibial nerve block and then looked at pain scores. Does that ring a bell? 

And what do you what do you think about that? Yeah. We we had done that for for a time. The group in Hartford with Sanjay Sinha and Jonathan Abrams, they had they had published on that selective tibial nerve block. And their problem in Sanjay's comment was, and we found the same thing was, it did work to cover the back of the knee, but it just the patients did not enjoy having a numb sole of the foot. 

They felt it was, like, weird, that feeling. And so that sort of prompted them to then go on to innovate the iPac. And so, yeah, we so we did it for a while, but then, you know, I think iPac gets what you need for the back of the knee without the unwanted, you know, foot numbness. Gotcha. Gotcha. 

Okay. I mean, the only thing I've gotta before we go into your recipe, the thing that I'm always conscious of is, well, especially when I've done my multiple needle marks and my, my genicular nerve blocks is you've really gotta make sure the knee is presentable when you go into theater. Otherwise, the surgeon will say, has it was there a mosquito in the anesthetic room? Why are there so many pinpricks and bleeding marks everywhere? So you gotta really make an effort to to make sure you present the knee in a nice in a nice way. 

Right? That's absolutely. That's a very polite British way of saying that. I think our surgeons would not be quite so restrained, and and haven't been at times. Yeah. 

I think there's a lot of, optics to be managed there, so I will, you know, I'm quite conscious of not rolling the patient back to the OR with bloody sheets and and that sort of thing. Okay, Jeff. So listen. I want to we we made our audience wait long enough. I want you to imagine I'm giving you a guy, Henry. 

So Henry is your patient, and Henry's coming to you for anesthesia for knee arthroplasty. Tell me what you're gonna do to Henry and the sequence. Okay. Alright. So first off, I'd say, alright, Henry. 

You you're gonna get a total knee today. I don't know how Hold on a minute. Wait a minute. I drifted from from, I don't know, Yorkshire accent over to Australian. I'm just gonna stop the accents now, but Henry is That sounds like something from Mary Poppins. 

Sorry. Oh my that's right. So so the first thing Henry is gonna get is we're going to have him get up and use the bathroom and void his bladder. That's just to, again, to reduce the need for straight cathing in the in the PACU. And then we'll have him sitting on the come back to the bathroom, sit on the side of the bed with the operative side towards the foot of the bed, and you'll see why that becomes important in a second. 

So then we'll do our lidocaine spinal. Eighty milligrams of lidocaine is is our sort of standard dose. Uh-huh. And then I'll have Henry flop over onto his side, so on his on his shoulder so that he's lateral with the operative side up. And that gives me access to the back of the knee with ultrasound probe so that I can easily do the eye pack. 

And I I I like an eye I like doing my eye packs in the lateral position. Oh, I see. So that's why you want Okay. So you so you got get him to flop onto his side, operative side uppermost. You've already got his feet towards so just explain to me again so can get my head around it. 

So when he sits on the bed for the spinal, you've got him sitting so his operative side is closest to the foot of the bed. Is that right? Correct. Yep. That's right. 

So then you can just drop him on his side, and then the operative side is uppermost, and you can smack in that eye pack. Ah, you got in the lateral position, which is so much easier to do. Right? It is so much easier, especially in a big patient. So I want to love the medial frog leg eye pack approach, but it's just with the size of patients that we're doing, by the time the probe is in that popliteal crease, there's so much tissue hanging over the probe. 

I can't you know, it's challenging to line your needle up, and you have sort of limited range of motion with your probe. You can't you know, with the knees having been bent, you you can't really move it all that much. So I like I like a straight leg, lateral, and that way I can slide back and forth in the back of the knee and and have freedom of movement. One x. One x. 

I fax and then turn supine, and then we'll do the adductor. Uh-huh. We'll sort of hook up our our nerve stimulator so we can stimulate that nerve to vastus medialis and identify it and then, get in there, do the adductor canal, and then we'll, do the genicutors and then finish off with the cuties. And that's it. And we'll roll them back. 

That's the full recipe. So you are doing spinal, IPAC, adductor canal with nerve to vessels medius beforehand, then the geniculars, the nerve to vessels intermedius, and the cuties at the end. Wow. That's it. That's that's a package. 

How long does that take? Forty five minutes. Just kidding. I think our institutional record for all of that is somewhere in the eight to nine minute range. That is a mic drop moment. 

Now listen. I I I recognize, fully recognize that we are fortunate to have block nurses and trainees that can help position and move and block and all that kind of stuff. So, you know, the constraints of of each different health care institution, that may not be possible in eight or nine minutes, but, it does work well. So the one thing I forgot to ask you, which I know people are gonna wanna know, is if you can give me an idea. You told us about the dose that you that you drop in the spinal, but what about the volumes of local anesthetic for those different blocks? 

I know it's a ballpark, and it'll depend upon safe doses for each patient. But as a ballpark Yeah. So, so twenty mils for the adductors. So we're and splitting that up sort of ten and ten for the nerve to vastus and the saphenous. And then, you know, fifteen to twenty mils for the IPAC, and then three to four mils each for the geniculateurs. 

And then, again, same just a couple of mils each for the the cuties. So it it does add up. It ends up being about sixty mils of local, and so you do have to be conscious of dose limits and concentration and that sort of thing. Probably in a different episode, we'll talk about catheters and adjuvants and that sort of thing. But so those are the volumes at least that we're using. 

Interesting. And then all of your patients will get multimodals as well. Right? So you Totally. What do you give them? 

Paracetamol? Paracetamol. And, the they get an NSAID. Our NSAID is meloxicam Uh-huh. Typically. 

They all get a dose of dexamethasone IV in the Operating Room once they've been sedated. And then low dose ketamine, so usually between twenty to forty milligrams of ketamine as a single injection bolus and then carry on the acetaminophen and the NSAIDs throughout their postoperative recovery. And what about the o word? Everyone does get rescue opioids for for, because let's let's face it. We are doing motor sparing blocks, but those motor sparing blocks are also sensory sparing blocks to a certain extent, right? 

So there is the need for the occasional oxycodone. We do get some patients through opioid free, but most patients expect to and that's part of it. Right? Their expectations. But expect to want to use a little bit of opioid to get them through, their, you know, a particularly vigorous rehab session or whatnot. 

It's interesting actually. We're we're gonna close out on probably the most important comment of all, which is patient expectation. So if you set the patient expectation currently from the outset, that will completely revolutionize that the the patient experience. If a patient is expected to feel zero pain or if they've been told they're not gonna feel anything, they're gonna be very disappointed with this kind of recipe. Right? 

Whereas if they know it's there's gonna be something they know what's normal, then the outcome is very different. So patient expectation is key. Yeah. A 100%. Part of my spiel is I'll say to the patient, so we're gonna do all these blocks, and it's gonna help knock your pain down from what would be a nine out of 10 down to like a four. 

And so I sort of anchor their expectations at about a four, which I think is reasonable. So if they beat that, that's yeah. It's great. But I think I honestly, most patients are at about a four after. Well, listen. 

This is really for me, it's been eye eye opener as well, Jeff. I think probably about time this must be our longest podcast ever, and that's three. So that's not that not that difficult a record. So Just wait. So why don't we wrap up episode three? 

We want people to to have a think about the type of things I want us to discuss and and to hit us up. So there's a few ways they can get in contact with us, Jeff. Right? Yeah. Absolutely. 

So we you can get us at Twitter at block it underscore hot underscore pod. We're on YouTube at block it like it's hot. No apostrophe. You always you always give me the difficult one. We're also on Insta at block it like it's hot with underscores in between each word. 

I'm not gonna say out loud, but it's block underscore it, etcetera, like it's hot with no apostrophe either. We want people to to hit us up with the with the hashtag, on any of those social medias. Make sure they use that hashtag. And, also, we need people to to subscribe to the podcast and to give us ratings as well that helps get get us spread around to as many people as possible. Right? 

Yeah. Absolutely. And let us know what you're doing for total knees. If you've got some cool recipe that works amazingly for your patients that we didn't discuss or or comments or questions about what what we said, please please let us know on the on all those channels, and we'll we'll discuss it on our next one. Excellent. 

Okay, Jeff. Until next time. We'll we hope they all block it like it's hot. Until next time, guys. See you see you next time.