S3:E2 "Paravertebral: The King of Nerve Blocks 🤴 (Part 2)"

It's time for a PVB renaissance. So grab your Seeker solution and meet me in the discharge lounge. I'm Jeff Kadston. We couldn't be any more excited to bring you part two of the Para Virtual episode. It's gonna be fun, but it's complicated. 

I'm Amit Pawa. And this is Block it like it's hot. Hey, it's Jeff here. This is part two of our perivatuberial special. If you haven't listened to part one yet, I highly recommend pausing here and listening to that one first. 

Okay. Cool. Let's pick it up where we left off. But if I'm needling in plane from chorda to keflad, sometimes that inferior transverse process, depending upon where you position the paravertebral space on the screen, can act as a bony impedance to getting your needle into the right place. So I will often anchor the keflat part of the probe where it is on a transverse process. 

I'll lift the corded part of the probe up and rotate it out laterally so that it's resting over a rib. So I've got a paramedian sagittal oblique view Yes. Of the paravertebral space. So that's the one additional step I will add if I'm doing an in plane. But apart from that, you know, the the paramedian sagittal scan, do the same as you, the prep. 

Yeah. And and and that's that's the reason that you alluded to the difficulty sometimes in getting between the two transist processes, which is when we started doing this, I remember I remember being with my two fellows in New York with an ultrasound probe and a patient and saying, guys, we should try this with ultrasound guidance. Like, we can see things now. I think people are doing this now and trying to figure this out. And we had such a struggle trying to get the needle, get an image where you have and, you know, we got some big patients here. 

Uh-huh. Two bony structures and finding the right trajectory and vector to get a underneath the probe, and then b over that first transist process, but not then hitting the next transist process. Exactly. Exactly. And and so we I struggled with it, and then eventually just gave up on doing a sagittal in plane approach. 

Yeah. Now I did for a while Yeah. Yeah. Do a transverse in plane approach. Did you ever do that? 

So that is now my default for teaching. Oh. I do and and actually, if you speak to many of my fellows who might struggle and in fact, yes, that's a bit unfair. There have been a few that are like, oh, I really wanna do the paramedian sagittal because it they they made more sense to them. But the majority of my fellows are much more comfortable performing a transverse scan and kneeling in plane because you've got a large surface area over which you can visualize the pleura, and actually, it feels a lot more comfortable. 

They don't feel like they're having to negotiate between narrow spaces. So that is now my default My that is my default technique. And the beauty about that is you place the probe in the transverse scan. You can actually see in the same way that you scan the lumbar spine, you can see the spinous process dropping down, lying over the lamina of the of the virtual body below coming up onto transverse process. You can see that beautiful anatomy lining out. 

So, actually, I quite like teaching that as a default. In fact, I I must update one of my videos on that just to show what I do. So I like doing transverse in plane needling, for para virtual locks. That's my default, actually. Yep. 

Now here's here's a question for you. When you get that image, your your transverse, oh, there's my spinous, there's my lamina, there's my transverse process. Uh-huh. Do you then slide cranial or caudal to get off that transverse process? So you're talking about doing the the block at the point of the inferior articular process where the lamina is visible. 

Right? So, this is a technique that Manushka marker has popularized. So to to be honest with you, the 95% of the transverse in plane paraversal blocks I perform, I perform with the transverse process still on the screen. I've slid the probe down or rotate the probe laterally, I've got the rib out of the way. So I've removed the articulation of the a long axis view of the rib articulated to the trousers process. 

I get the rib out of the way. I've literally just got the trousers process on screen. I've got the pleura, and then the surrogate for the superior cost of transverse ligament is the internal intercostal membrane. That's the dream view I I I like to have. Okay. 

But there are some patients where either the space between two ribs or two transverse processes is very small, and a small probe movement will then bring the rib into view, and you suddenly haven't got a nice view. There are some patients when I will think, well, do you know what? I'm gonna do exactly what you described. I'm gonna slide either up or down off that transverse process to remove the transverse process from the view. And when you look at the screen, the medial bony landmark you'll see will not be the transverse process, but it'll be the lamina. 

And then you got lamina and pleura and internal tocostal membrane. And that will be and that's actually much easier position in which you can needle because you got less bony impedance. The danger behind that is if you don't recognize that that's the lamina on the screen, you can drive your needle right into the central neuraxis. Uaxis. So that you just identified my biggest problem with the transverse in plane approach. 

You're driving your needle right towards some really important real estate. And so so I I don't like that for that reason. I'm a I'm a sagittal, paramedian sagittal out of plane. And I what I like about obviously, I like my technique because that's what I do. But what I like about it is it's safe. 

I feel like I'm not gonna hurt anything because of my puff, puff, puff, puff, and it's fast. And I do every level. Uh-huh. So if I'm doing breast, I'm doing two, three, four, five, six, and it's it's quite quick. Puff, puff, puff, puff, puff, boom. 

Okay. Next, puff, puff, puff, puff, So the reason I love these conversations that we have is because it always just it it kind of challenges me to think differently. So John taught me the paramedian sagittal. John MacDonald told me that because he didn't like driving the needle towards the access exactly as you described. So he never taught me that. 

He's a wise man. And we in fact, we made a video for a company a long time ago talking about paravertebral blocks. This is one of the reasons we talked about paramedial sagittal. We only promoted that. So it felt like a massive shift in my practice when I when I did something naughty. 

I felt like I was cheating on him because I was doing something that, you know, he taught me never to do. But what I like, and I don't think I can deny about your out of playing technique, is the speed. Because you're whilst you obviously do have attention to detail to identify the needle tip, but because there's it's a slightly different pressure, you're not aiming to get a shaft and needle tip the whole time. And I I don't think because the amount of tissue you traverse through with an outer plane versus an in plane, it it feels like a much quicker to get to endpoint technique and that constant injecting as you go approach. I can imagine it would be much quicker to perform four or five levels than it would be doing at my technique. 

And for that reason, I might don't quote me on this, but I might consider trying it next time. Well and you know the reason it's it's quicker is because you have to let go of the idea of seeing your needle tip. If I'm trying to get someone in plane to see their needle tip in a in a rounded structure like somebody's back, it is you you've seen this. Right? Like, they'll be, oh, stop, move your probe back, get the you know, oh, you lost your tip again. 

And there's a lot of that sort of fine tuning as you're going in plane. Whereas if you let go of the idea of I have to see my needle tip and just use saline as your surrogate, then it's this beautiful, liberating feeling. Like, okay. I I know I'm not gonna see it anyway, then let's just use a surrogate. And that way, you don't have to worry about that that part. 

You know, I've I I do know some people have done outplaying with the transverse view as well, which is interesting. Yeah. I have not done that. No. I think it's something it's something I'm gonna consider doing. 

But before we go to a little break here, a little interlude, I want you to help me out here. So let's assume tomorrow, I'm gonna try and and do exactly as you've described. I'm gonna do I get my probe from lateral over the ribs, get to media over the transverse process. I introduce a little bit of a tilt, latching in order to visualize the pleura. When I'm so I've got so I'm imagine the patient either sitting or prone with that orientation. 

When I'm gonna drop my needle in, are you dropping your needle in on the lateral side of the probe as opposed to medial side of the probe? I'm guessing the answer is yes. Yes. Because because you slid your probe medially to get TP, and then there's a slightest Yeah. Lateral tilt of the beam. 

Yeah. And then if you if your needle comes straight down, you've created this nice little v Yeah. Of beam and needle. And in relation to and so in relation to the probe and the angle of the probe, you're not going completely parallel because, of course, then you would you'd miss the beam. Correct. 

Angling it slightly towards the angle. Just help me visualize that. Yeah. Just just just enough. So I I I get to the tipi, and I'll tell the trainees, you know you're at tipi for a couple of reasons. 

One, you've got a change in your bony structure. You've gone from rounded and deeper to flat and shallower. And also, you've lost the pleura. You can can no longer see the pleura movement. Or is it the bare the barest hint of a pleural movement there? 

Yeah. So just do just a slight tilt to get the a nice crisp line of pleura back, and you'll be at the lateral recess of that perivatuberial space. Okay. Alright. Listen. 

May maybe maybe next time you speak to me, I would have done one of these out of plane. And if you change my practice, that'll be the third time I've changed my practice for para virtual blocks in my career. So listen. Let's just have a little break here unless there's anything else you wanted to talk about. Anything else you wanna talk about before the break? 

I think we're due I think we're due for a break. Yeah. Well, listen. Do you I know you told me you did your training in paraversals in the nineteen hundreds, but but do you remember vinyl records? Yeah. 

Yeah. Well, see, you know, yesterday, I bought my first, my first vinyl record, and it was, it was, a disc called sounds wasps make. Sounds that wasps make. Wasps make. Wasp. 

Yeah. So so, you know, when I got home, I thought, you know, I'm gonna listen to this. So I put it on. I thought, do you know what? That doesn't sound anything like wasps. 

And then I realized I was playing the b side. Sorry. Sorry. It's that's good. I like that. 

Not bad. Right? Yeah. Not bad at all. No. 

I I didn't know where that was going. Yeah. Well, that was kinda I was trying to channel my inner Jeff. Right? I was trying to do that. 

Yeah. Yeah. Yeah. Yeah. Yeah. 

And and what did the anise to say, to the patient when he was performing a paravertebral block? You know, the patient was nervous. Anise is doing a block. What did he say to the patient? I don't know. 

Don't worry. I got your back. Oh, that's Okay. That was chat GPT, by the way, just just to put into into context. Okay. 

Give me hit me. Hit me. Give me something. Oh, do you I it's funny. It's it's this lifelong learning bit. 

Right? Like, I I keep learning new things about science and medicine that that that I I never knew in in medical school. So do you know you're actually born with four kidneys? No way. Yeah. 

But when you grow up, two of them become adult knees. Kidneys. Adult knees. Okay. Alright. 

Very good. Anatomy joke. Yeah. They do. Or Do you know yeah. 

That's very that's I like that. I like that. Have you got another one for me? Well, it's more of an anecdote. So, like Okay. 

You know, I it's the new year. Uh-huh. I I thought I'd start off the new year with getting to one of my resolutions, was to do some more some more relaxing hobbies. And I've taken up painting Uh-huh. Which is something that I've never I've never explored before. 

Like, I've I've done some music stuff in the past, but never really, like, visual arts. And I did my first nude painting yesterday. Oh my goodness. Me. Yeah. 

I got right into it. Right? So now the neighbors weren't happy, but the fence in my front yard looks as good as new. Oh my god. That is I'm sure it's not just me or BR listeners that got this image in their minds of you. 

Well, shifting very quickly from one type of nude painting to another. Oh my goodness me. Wow. Okay. Well, thank you. 

I don't really know what to do with that. I just there's something else that I did that I did wanna mention actually. Pause and savor that image for a second. Exactly. Do you know do you know one of the things that we did do around Christmas was and this is not a joke. 

This is a true thing. Is are we, we went to see Mufasa, the, the animated Yeah. Real life kind of movie thing. And it's interesting. There's there's a great bit of wisdom. 

I've heard a few of our regional anesthesia colleagues talk about, and it was quoted in that movie. They've actually made a song about it. I just wanted to just to to share that that great story here. So there's there are these two brothers, and I won't spoil the story. This is the prequel to Lion King. 

And one of the phrases they come up with is if you wanna go fast, go alone. If you wanna go far, go together. And that's something that, you know, people talk about as principles in life and, you know, the academic achievements. But this this they made a whole song about this in Lion King. And I remember I'm I heard Karimel Bogdadley talk about that. 

We talked about collaboration and improving, research opportunities at Guy's and St Thomas and how we've done that. So that kind of stuck with me. I don't know. Just thought it a cool thing. I was gonna make a TikTok about it. 

I thought rather than make a TikTok about it, let me share Yeah. That great piece of, of information from that film. So if you haven't got a chance to see Mufasa, go and see it. I think it was brilliant. I like that a lot. 

I thought you were gonna say you you heard Kareem singing the song. No. But but now I would love to hear, obviously. I was so close. I was almost gonna break into song just then. 

But I do know what? Save it for TikTok. I will I will record a video, on the tick on TikTok later. Okay. Listen. 

I feel like we've had a nice little break and stretch our legs. Any other jokes before we get into the the the tail end of things? No. Let's let's get back to it. Okay. 

So I wanna use the term seeker solution. Do you know what I'm talking about? I imagine it's the like, what you're using in the syringe before switching to your actual local anesthetic. Yeah. Exactly. 

So so I I think I think a lot of North American anesthesiologists, at least, has used this a lot, especially for fascial playing blocks, especially when you when you got limited volume. So but I know it's not necessarily a common thing in on this side of the pond. But, yeah, I was taught to use a seeker solution or a hydrolocation solution for my para virtual blocks because as exactly as you've described, doing your puff, puff, puff, puff on your way down, whether it's in plane or out plane, if you don't have a solution you're prepared to waste, by the time you get to the endpoint, you're gonna end up wasting all of the volume of local anesthetic. So I and I know you've talked about this before. Yeah. 

But I know that when I use this term, to a lot of my residents, they they're initially confused. They're not aware of it. So I use a seeker solution. I tend to use lidocaine with epinephrine. What about you? 

We I typically use saline. So we have these, you know, buckets of 10 mil sterile saline flushes. And so I'll grab you need to grab, like, three or four of them for a set of paravertebrals because the truth is that you can end up using a fair a fair amount of secret solution on the way down there depending on how easily that, you know, needle pass is by the trainee. But so it's not uncommon for us to go through, you know, five, six, eight mils of saline on the way down to the pleura. Per level? 

Per per per level. Yeah. Sometimes and and you'll see as a as a trainee gets more and more experienced, they can drive their needle in further with confidence before you have to start using the secret solution. Yeah. And oftentimes, it's only like one or two puffs before we see pleura. 

That's interesting. Because because I normally draw up about eight mils eight to ten mils as a maximum of of Seeker solution. And often doing a single level for analgesia, I tend to do a single level. But I was taught to use epinephrine containing solutions because there are blood vessels there, and it just is a warning sign of whether I've got an intravascular injection or not. So that's I kind of stuck with that. 

The reason that I'm happy to use a lidocaine containing solution, especially when I'm doing awake surgery, is as we know, and we this is going to form the next part of a discussion, local anesthetic injected on the way down to the paravertebral space is not wasted, because it may still be having a role. So I kinda figure if I'm gonna be injecting a solution on my way down to identifying the para virtual space, and my first test injection is gonna be deep to the transverse process, why not use a solution that's gonna contribute to analgesia slash anesthesia as opposed to dilute the effect with saline? So that was just something I wanted to touch on. Yeah. That's that's a fair point, actually. 

Yeah. If you're if you're that close when you're using it. Yeah. But, again, you you one needs to be aware of total doses of local anesthetic administered, etcetera, etcetera. But, yeah, it was something to to bear in mind. 

Now you've already alluded to this. You are a multiple level injection kinda guy, whether you're doing it for analgesia or anesthesia. Is that correct? Typically. And there's a couple of reasons for that. 

One is that we we can assume that there is some continuity of the paravertebral space above and below. And so it's attractive to think, oh, I'll do one injection at T4 and with, you know, twenty five or thirty mils, I will get up to T2 and down to T6 or seven. I'm not so sure it works that way every time. I don't think it's quite as easy a passageway as say the epidural space. So for that reason, certainly if I need surgical anesthesia, I am doing every level. 

And if I'm doing analgesia, especially if I'm doing two sides, that's a lot. Like, I had to do like five on one side and five on the other. That's that's a that's a lot of pokes. So I might do two. I might do t three and t five on one side, t three and t five on the other side, and that's four pokes instead of 10. 

And I'm doing an LMA anyway and Interesting. You know. The other reason I I I tend to do multiple levels is for maximum resident benefit. That's right. Just so they get their reps in. 

Yeah. I think so we again, we've got, I think, if we had a block room, we might get a bit more MRB. But because we don't and sometimes we've got surgeons peering through the anesthetic room door and if things have taken a while. So so so we've got we've always got to try to find line between efficiency and efficacy of the technique that we're that we're introducing. So I am, and I have been for analgesia, a single level guy. 

And, mainly because it's kind of for the last, goodness me, coming out for fifteen years now, it hasn't let me down. And, thankfully, that was backed up by a paper that Vishal and his colleagues published a while ago showing the different dermatomal levels covered by a single level versus multiple level paravertebral block. And in fact, in those guys, in that study, they also did all of their blocks with the patient in a prone position. I wonder whether that has a difference or whether that has a role. I'm not sure. 

But I so so I you know, there is some evidence based on what I've done, but in my clinical practice, I've for analgesia, I've always done a single level. And if I'm doing it for anesthesia, then I do between three and four. But, there's no doubt that when you're looking for surgical anesthesia, the more levels that you do, the more of a comfortable experience the patient will have Mhmm. And the less reliant they will be on sedation. When I, you know, I I have done a wake surgery. 

Yeah. With a single level power of virtual block and augmented with with with a PEX two, essentially. That's what I used to do in the old days at one of the first papers we published. But there's no doubt there were some ropey areas where you needed to maybe crank up the sedation a little bit. Since I've switched to multiple level, it's generally a lot it's a lot easier because you know that you're getting a, you know, a nice definitive surgical anesthetic at the end of it. 

Yeah. Yeah. Yeah. And, and that makes sense. And it's good to hear that you can you can do that with, I never I don't think I've ever felt confident enough to do a single level and then try that for surgical. 

We will for the cardiac surgery, as I mentioned before, we'll do often three levels. We'll do Yeah. Sort of one at t three, one at t six, and then one, t nine because their chest tubes go Uh-huh. You know, down in the lower thoracic zone and sometimes in the in the abdominal area. So that's a case where we'll do exactly the same thing. 

We'll just we'll pick three and hope that two or three and hope that it spreads up and down. And per side of the chest, what volume of local anesthetic are you using as a general rule? I've always done about 25 to 30 Yeah. Per side. Yeah. 

So I've kind of been a 20 per side kind of guy and kind of it's interesting because the one time, I had a colleague with me, and he said, why don't we, you know, inject I can't remember what it was. When it was when it was thirty or forty mils of low clonso, like, boy, oh, boy, were we using vasopressor for the rest of that case? We got a massive sympathectomy with 40. So, yeah, I've kind of stuck around 20, and that seems to be that seems to work for me. Well, can I stop you there for a second? 

And I because I think that's you've raised a good point, which is we know that with enough volumepressure, can force local anesthetic around the front of the vertebral body to the other side, the contralateral paravertebral space, and maybe there's some epidural spread through the intervertebral foramen, although I think that's probably overstated. But that's another reason, thanks for reminding me, that's another reason that I tend to like the multiple levels because it's only four or five mils at a time as opposed to a big huge volume, which Yeah. This is just in my mind, completely anecdotal, might be more likely to go around to the other side. I don't know. Yeah. 

That's a valid point. Yeah. No. I think I think that's a I think that's a fair point. I just I don't feel comfortable injecting larger volumes than that, but I've it's never occurred to me that one of the benefits of multiple injection points is that you're less likely to cause that that contractual, spread. 

Because, of course, when I first started, doing these techniques, I remember speaking to Jens Borglum, and he was very fascinated about the chance of getting a sympathectomy or not and whether there were any because we think a sympathectomy actually is beneficial in terms of block quality. Sure. And Yeah. And whether there are any things that you could do to increase the chance of getting a sympathectomy at a given level. And if you look at a cross section of the paravertebral space, there's this thing called the endothoracic fascia that kind of cuts through the paravertebral space and anterior ventral to the endothoracic fascia is where the sympathetic ganglia are positioned. 

And the question was, is there anything you could do to maximize the chance that your local anesthetic spread would go deeper into the paravertebral space and cross the endothoracic fascia, which is not a strict membrane per se. So the only thing I used to do anecdotally is once I got my pleural depression, was I just used to advance the needle just a little squidge further towards the midline. I don't know whether that made a difference or not, but I kind of think this is our sort of tips and tricks section of the, paraversal block. Is are there any tips or trips that you wanted to share? I maybe not. 

Maybe maybe I don't have any. Well, I I mean, to be fair, I I think you've I think you've shared a lot of your puff puff squirt tips on the way here and talking about needle angulation. But what I wanted to ask you is and again, this That's my actual middle name is puff puff squirt. But but you, you alluded to the fact that you don't have the patients very heavily sedated because you've got them in the sitting position. So do you get the PPS? 

No. PPPS. You're, of course, referring to the pain of pleural peeling sign of success. Oh, yeah. Oh, but that's actually the good powers Oh, PPS. 

PPS. Yeah. You know, that that's a that's a great point. So we we will caution the patients ahead of time. Say, this is you know, we're gonna put some skin local in. 

It's gonna feel a bit crampy as the needle goes through, and then you're gonna feel this weird pressure sensation. And that's a good thing. You know, when the patient goes, ugh, ugh, ugh, and we're like, we all start clapping and say, okay. Congratulations. You're gonna have a great block now. 

You know, positive reinforcement. But, yeah, that that's what you're talking about. Right? Exactly. Right. 

So I so I would go as far as to say if the patient doesn't manifest that noise as the pleura is peeling away from the anterolateral surface of the vertebral body, if they don't make that that groan noise, I would be one I'd be wary about how successful that block could be. Can we can we coin the term power's grown? And Again, this is gonna be a lovely late night podcast version. But, yeah, power's power's great. Power's plural growing. 

The you know, the the power pleura peeling, painful peeling sign, something like that. The the four p s's. But I think it's a real thing. So when the patient makes that noise, I think, yep. I know that block's gonna be good. 

Yeah. Yeah. I agree. I think another thing that what has changed in my practice, and this has been informed by some really cool anatomical studies that people have done, is the realization that you can get a very successful block of the intercostal nerve and the simple and, you know, that whole paravertebral type space by not going too deep. So because there are holes and slits in the cost of transverse ligament that allow you to put local more superficial, so like an MTP type block, and this has been described in this so called retro superior costotransverse ligament space, which is a mouthful to But the idea is that it's amazing to see that pleura go down and you have that paua's grown of the patient. 

But if that is too fine of a line to cut and you're nervous about getting so deep, then you're probably okay to be several millimeters more superficial. And there's times when I've gone puff, puff, puff, puff, puff, and we see expansion close to the pleura, but not that pleural depression. And I'm like, you know what? That's gonna work anyway. Let's just move on to the next space. 

I think that's really important, and I think that, what it emphasizes is that exactly that change of understanding. So two things to pick up on one. That one paper, I think it was Cho et al, c h o et al. I I need to double check, but that paper looking at micro CT slices of the paravertebral space and showing the medial and lateral slits was absolutely incredible. Yeah. 

Because it kind of and that that came after we described the MTP block, but the the description of the MTP block came about. So Ioana Costash called me at an ISURA meeting in Toronto, and said, Amit, I've watched your video that you made for Elsora, and I wanted to ask you something. Did you notice that when your needle was dorsal to posterior to the superior costotransverse ligament and you injected local anesthetic, the pleura depressed. And then you advanced a bit further to cross the ligament and then depressed even more. And, actually, at the time that I recorded the video, I'd noticed it, but it wasn't a conscious Mhmm. 

Recognition. I kinda seen it, but I'd never assumed or just knew I had to cross the line. And she said to me, I think that you don't need to be deep to the superior cross of transverse ligament in order to get an effective block. So that's where the idea behind the MTP block was born because we used to be told, right, unless you cross that superior cross of transverse ligament, your block will fail. Or at least that's what I was taught. 

And this paper, this beautiful paper gave us an anatomical reason. Again, confirm the reason why Yeah. There are different paths from that's the retro superior cross to transverse ligament space. A local assay injected there can get into the paravertebral space. So, actually, we can use that as part of our strategy. 

Right? So and that's where this whole idea of start off by doing an ESP block, maybe do some pepper potting, then do an, MTP slash ITP block. And all of these potentially have a role to get to a final destination of the paravertebral block. So, yeah, you said sometimes, especially if you're doing multiple blocks, if you can't quite get your needle deep to the superior cost of transverse ligament, but you can still deposit some local ancillaries there, it might be okay. It might be good enough. 

And you may still get some pleural depression. Are you still trying to popularize the block term Peppa pot? Oh, yeah. Exactly. How are gonna block it? 

The other thing, that is very relevant with tilting and angling the probes and needling in plane so you don't have this issue so much without a plane needling. But if you're gonna needle in plane, the moment you change the angle of incidence with the probe and the patient's skin away from 90 degrees, when you're needling in plane, you have to be cautious because to visualize that needle in plane can be a challenge. And often, I'll try and get my residents to play in a Phantom. I'll say, right. Here's a probe at 90 degrees. 

The skin now needle in plane. Now direct your beam, so flip the cord towards the the left or the right so you're tilting the beam, medial or lateral, and see actually how much more difficult it is to needle in plane. And that can be one of the issues with in plane perivertical needling in the paramedian sagittal oblique plane is you've introduced so many twists and and curves onto the probe that to ensure you you visualize a needle can be a challenge. So that's one thing, that would say. And before you're practicing on patients, do you have a play with a phantom and workout? 

Sometimes you need to insert your needle ever so slightly off the midline of the probe in order in order to see it. You notice that? Yep. Yep. That's a good point. 

The other thing again is when you're when you're when you're using a transverse in plane scan of the para virtual space, so you're scanning transverse plane and you're gonna need a limb transverse orientation, you're gonna need a plane. If you insert your needle right at the lateral end of the probe, by the time you get down to the endpoint, you've got a really steep angle. So actually, there's some value in bringing your needle insertion point a little bit further away from the lateral aspect of the probe. So when the needle does appear into the skin, you've got a less acute angle. Have you have you seen that? 

You should re reduce the steepness of the probe of the needle angle by coming a little bit further away? Yes. We do that. We for virtually all our blocks, actually, if you have the room to do it, then that way you have a a more shallow trajectory and you see your needle better with ultrasound. It's a good it's a good tip. 

Absolutely. Tell me about catheters, Jeff. Do you use catheters in the paraverteal space? You talked about rib fractures. Any tips for your catheters? 

So the the tricky thing with catheters, a couple of things. One is the angle. So the way I've just expounded about how we do our blocks is you're coming out of plane. Now you're coming at 90 degrees of the pleura and the perivatuberal space. So how do you make a catheter, you know, then turn a corner and go either cranial or caudal? 

I tend to, in this case, use a slight slightly oblique angle. So instead of coming out of plane straight down, I'll come out of plane, but but with an oblique angle from caudad to cephalad, and I'm using a Tuohy needle. So the combination of those two things means that the opening of the Tuohy needle is more or less pointed cranially. And so when that catheter comes out Yeah. It just sort of skips up all in the peripetribral space. 

I this is a case where I think you do need to be past the cost of transistor ligament in the true perivatuberal space, and you can't like coil a catheter up in the MTP space and think, oh, it's gonna work for multiple multiple levels. Although people have done that, but yes. Yeah. Well, yeah, I mean, I think you can overcome a lot of anatomic deficiencies with volume. Yes. 

Yes. With as we've talked about before, but but the a a more elegant way to do it is to make sure you're truly in the peripaterbral space and get that nice, beautiful spread up and down. The, not putting too much catheter in is also important because I've had catheters definitely go wonky places, maybe head out towards one intercostal, you know, follow the nerve out and we only get no matter how much volume we put in, we we only get one dermatome. Or the reverse is more concerning if it heads towards the intervertebral sorry, the the epidural space. Then you get an epidural catheter, which is not the worst. 

You know, it's a good it's a good analgesia, it's not what you were intending. So don't put a lot of catheter. What's the ultimate, distance? Will you throw it at three centimeters maximum? Three or four? 

Three or four is what I'm aiming for. Yeah. And then, and then, you know, like a lot of fascial plane infusions, it's it's important to have an intermittent bolus. So and there's a paper I'll I'll leave a link to a paper, in the show notes about about intermittent bolus for paravertebral catheters versus just a continuous infusion and how you end up getting a higher quality of block and better dermatomal spread. Yeah. 

I think we we we did a study which we never published in cadavers doing ultrasound guided coiling catheters in cadavers, and then we did fluoroscopy to identify the catheter position and then did dissection. And what was amazing about that study, it may have been a floor of the practitioner, I e me, or the the the the needle and the coiling catheters that we use, but a large number of those catheters ended up in the wrong space. So either mediastinal or intrapleural, certainly a larger number than you would be happy to have on the ward with infusions running like that. Although intrapleural analgesia is, of course, a a recognized route, but you wanna know where your catheter is. So on that note, I thought we'd kind of talk about some of the complications. 

So, the big thing we people, you know, was talking about you're talking about a blockage failure. Have you ever had a failed paravertebral gel? I've heard about them. No. I I think the answer has to be yes. 

I'm trying to think of a specific instance, but especially with landmark where you weren't quite sure where your needle tip was. I'm sure we were doing MTP blocks a lot of the time with Landmark. Yeah. And but because we're doing every level, that probably glossed over some of our anatomic failures. And we showed in that little phantom study that a lot of the time, your needle is not where you think it is. 

So Mhmm. How about you? Well, I would have loved to say no, but I what I think as you know, patients are a a whole host of different, you know, phenotypes. So some patients, you do if you take two identical patients and do two identical techniques, you won't necessarily get the same outcome. There's many reasons why that may be the case, but I've got a very, very specific memory in my mind of the first Vertigo was failed single level paravertebral block I did, which I think was just manifestation of a not good quality enough block. 

We had two patients having the identical procedure. The first one who happened to be a VIP, it's always the way. I did a single level para virtual block, but at the time of doing it, I wasn't a 100% happy that the needle tip was deep enough, but I accepted it and did it. It was fine, and they were gonna have a GA anyway. Okay. 

The second patient having the identical procedure had a much more beautiful poof. Nice. Nice end point, all the rest of it. And I went to follow-up on the VIP patient in the discharge lounge of the of the unit I was working in. Oh, I like that I I like that term, discharge lounge. 

But I went to follow-up this patient in the discharge lounge. And when I walked in, I could see the two patients, the VIP patient who had the maybe not so great block, and the second patient sitting diagonally opposite each other. The VIP patient didn't look so great, sort of a bit achy, and the other patient stood up and and and screamed and said, oh my gosh. I love you. I feel amazing. 

I ran and gave him a massive hug. God. That's always the way. Right? So I saw a stark difference between a really great and effective block and one that wasn't so great. 

So, yes, I guess I have had a failure. The other failures I've had have related to where I've maybe not timed the the locate or not not, put the location of my single shot block in the right area. So I've I've done a great block, but it hasn't quite covered all of the surgical, area or the chest drain has come out below where my surgical anesthesia is or my surgical analgesia is. So that's another reason why multiple blocks are beneficial. So I've done a block that's worked, but it hasn't been good enough because it hasn't covered the whole area of surgical nociception generating tissue. 

I don't know. I think another thing that is a area of confusion for some of our trainees is which levels are required for breast surgery. And and the answer is, in my mind at least, t two, three, 456. Yes. And then, but occasionally someone will say, I need to get t one. 

Yeah. To get a good block for the breast. And I'm like, let's talk about where t one is. I'm gonna go through the, we'll go the brachial plexus, more like, where's where's c five? Where's c six? 

Innervate. Where's c seven? Innervate. Where's c eight? Where's t one? 

Oh, yeah. That's the arm. Mhmm. Yeah. So you don't really need you only need that for the anterior chest. 

The anterior chest goes c three four and then skips right down to t two. Yeah. So T two, 3456 are what we do for is that what you do for breast as well? Yeah. Although, if I'm doing a wake surgery, and they're doing an auxiliary node dissection, I might sneak in a t one, t two, injection to see if I can increase the chance getting my intercostobrachial level. 

So I might I might go a little bit higher. So that's that's not a bad point. I mean, terms of, like, hedging your bets in case you have, you know, spread that is not perfect at t two, then yeah. Okay. And then the higher I go or the deeper the needle is in the paravertebral space, the the greater the chance of getting, a sympathectomy. 

At that point, I want to talk about Horner syndrome. And again, I remember talking about this in the past. I was once told that if you've done a good paravertebral block, if you look your patient in the PACU, from the end of the bed, you should be able to tell which side the block was on by seeing which side they've got a Horner syndrome on. And, of course, often, you know, the Horner syndrome is ipsilateral ptosis, meiosis, and anhidrosis. But have you heard of Harlequin syndrome? 

Yeah. Yeah. Harlequin's that one where you have the the flushing on one side. It's like patchy. Right? 

Left side is no. Go ahead and tell me. Yeah. They said no. So you're you're absolutely right. 

So I heard about this because I I was sent a picture of a patient, who'd had a perivisible block, who developed Harlow Cone syndrome. And in fact, there was they this was published in the paper. They get contralateral facial flushing and sweating Okay. Due to sympathetic nerve block. So on one side, they've got a sympathetic nerve block because of the block. 

And on the contralateral side, they get facial flushing and sweating. And it's it's really interesting. There are there are there is a detailed paper. Have I a funny feeling Donald Buggy might have written it, but there's a there's a paper out there talking about the potential mechanisms for Harlequin syndrome, but it's it's it's fascinating. But, yeah, it's the consequence of getting a really great, sympathetic to be a one-sided and and the lateral manifestations. 

It's almost like you got a division in their face where you can see this facial, flushing occurring. What about pneumothorax? What do you think the real instance of pneumothorax is? Completely unknown. I mean, it's with landmark technique, not zero. 

People say one percent, six percent, something in there, and I could see that. Now to get a pneumothorax, you have to allow gas into the pleural space, and that gas doesn't typically come from your tubing syringe system. You have to go even further, puncture the visceral pleura, get into and essentially create a bronchoplural fistula. So the gas from inside your lung is then filling up the the pleural space. Do you agree? 

Exactly. I'm so happy you said this because when you think about it, it's actually really hard, I think, for a needle connected to a closed loop system to create a pneumothorax just by puncturing the parietal pleura. Yeah. I think it's really hard. And I have been involved in one case where a patient developed a significant pneumothorax. 

It happened to be that that patient received a, paravertebral block from me at the beginning of a nine hour case. They behaved beautifully, ventilated beautifully the whole way through the case. Part of the surgery involved an anterior rib resection and some work under a microscope. And at the end of the case, the patient coughed, and had a precipitous drop in saturations and very obvious pneumothorax at the end, had a 50% pneumothorax, and had to require a chest strain. So I spent the whole of my time chastising myself about the fact that I'd done a, you know, a paravertebral block at eight or nine hours earlier, and that causes pneumothorax. 

And I spoke to another surgeon who was an upper GI surgeon, and, this individual said to me, I think it's very, very unlikely that you were responsible for that for that pneumothorax. Talking about the mechanisms required in order to generate pneumothorax, actually, things should have manifested a lot earlier. And if you've if you've got a surgical cut on the, you know, on the anterior rib and you're working close proximity to the pleura and the patient coughs, there's another mechanism by which that happens. So I agree. I think the incidence is very low. 

I think people used to quote, you know, one in five hundred or for example, to get a pneumothorax of which, you know, maybe one in four of those might need a chest strain. But now, certainly, there's a a whole host of studies looking at the instance of pneumothorax from perivertical block, and, certainly, they've had pay you know, patients of, you know, up to four thousand with no new authority. So I think the incidence is much lower than we realized. The other I agree. The other thing people worry about is altered hemostasis or patients on anticoagulants. 

And and I know that, this is a bit controversial. What is your feeling on this? So I think the thing that that that doesn't help is that different guidelines give different advice potentially. So my personal feeling is, as with every regional anesthetic technique, risk benefit discussion, but in most patients, I would be prepared to do a single shot block even in the presence of anticoagulants if I felt that the benefits of the technique outweigh the risks and if I had the patient on board with it. So Yeah. 

I guess what I was saying is anticoagulation is not, for me, an absolute contraindication to paravertebral block. How about you? Yeah. Exactly the same. So I'm glad you said the risk benefit thing because the benefit of a a well done paravertebral block is so profound in terms of the analgesia, the sympathectomy, and the the ability to carry out surgery with with minimal anesthetic and opioids and blah blah blah blah blah. 

So the benefit is great. The the risk so I'll ask my trainees two questions. Number one, have you ever seen or heard of someone aspirating blood during an ultrasound guided paravertebral block? And to date, no one has ever said yes. And I'm trying to think. 

I I I don't think I've no. I've never seen that. Never. I I no. I I agree. 

And so, anecdotally, no one seems to have a high incidence of it's not like an epidural where one in ten, I'll get a bloody tap or whatever the number is. Mhmm. But the other question is, I say, okay. Let's let's just say for the sake of argument, you got a hematoma in the paravertebral space. What is the consequence of that hematoma? 

Where's the blood gonna go? And I'll have them draw out the epidural space and I say, here you have the vertebral body, intervertebral foramen, the transverse process, and the pleura. Now, what are you worried about? Are you worried about a spinal hematoma? Like a compression of the spinal cord? 

And a lot of them will say, well, yeah, we're so close. I said, do you think the blood is if there was an expanding hematoma, do think the blood is likely to go through this very narrow bony canal, the intervertebral foramen, that is occupied by a nerve root, by the way, and then into the epidural space? Or do you think it's gonna take the path of leaf resistance and just push the pleura in a bit? And they're like, oh, I guess it'll the pleura in. Yeah. 

And and also go sort of cephalad and caught it. Now you could have a big collection of blood. I mean, you were I was gonna say, yeah, we don't wanna understate that, you know, you do hit a blood vessel and there are some big blood vessels there, it's not to say it's without risk, and it can be without risk for sure. Sorry. It can it can cause significant, hemodynamic collapse and compromise if you get a massive collection, which you could do. 

Yeah. I've never heard of one. Listeners, please let us know if you've if you've ever heard of or experienced one of Not to say it couldn't happen, but I think what what I want to stress is that people seem to lump paravertebral in with neuraxial in terms of the the risk profile and the actual adverse event itself, and it it's not true. You will not get a spinal hematoma from a pervertebral hematoma. Agreed. 

Well, I'm gonna stretch you one step further then, Jeff, in that case. Did you ever have stretch did you ever stretch Armstrong when you were a kid? Is that a is that a thing? Yeah. That was a it was a thing. 

I never had one, but I I know what you're about. This is this character you could just keep stretching, and it'll always come back to its original shape and form. Right? Until one day when you did it too much and then all this blue goo came out of came out of Stretch Armstrong, which is probably probably wildly toxic. Actually, exactly. 

I think I might have played with somebody's, but I I never had my own Stretch Armstrong. I would like one now, though. So if anybody has a spare one, please send it to you. Block it like it's hot. No. 

So yes. To to stretch you a bit further, you said that you, like me, you would do a single shot paravertebral in somebody that was fully anticoagulated, potentially. What about a catheter? Again, not no. I mean, I have to make a risk benefit analysis and talk to the patient, talk to the surgeon, and etcetera, etcetera. 

So I'd be a little more thoughtful. It's, you know, with a catheter, it's more likely to encounter a blood vessel as you're threading the catheter up. So I get that. So I so I see that. But I you know, an ESP catheter, you wouldn't think twice of presumably, I'm guessing? 

No. No. In terms of anticoagulation, no. No. Right. 

So interesting. I was doing a live demo, somewhere. I can't remember where exactly, and I was scanning somebody's, teaching how to do an ESP block. I put the probe in the back. It got into the rectus minor plane, and this patient had the largest collection of blood vessels traversing through, that that that space between the transverse process and the rectus minor muscle complex. 

So there's a couple of numerous big blood vessels there. So I guess the point is, as with any technique, no technique has a risk profile of zero. Just because you're picking up safe technique, it doesn't mean that there are not complications that could occur as a result of them, but I guess you have to look at the impact of that complication. So a blood collection in a superficial muscle bulk in the back is gonna be less worrying than a blood collection in the epidural space. So, yeah, risk benefit discussion, but I think definitely I do a single shot para vessel block in somebody's anticoagulated catheter, I would need to think carefully about. 

And it sounds like, Jeff, you're probably the same, although you you might be a bit more pro catheter than I am, potentially. Yeah. I think that's fair. And and so I think if I were to sum up our collective views on complications and risk, I think both of the mind that the risk of bad things like pneumothorax, bad hematoma, etcetera, is is actually probably very, very low. And so this helps I think this is as this becomes more entrenched and more and people sort of recognize this and recognize the benefit of PVBs, that's gonna help with the renaissance of the technique. 

Absolutely. Yeah. So I I mean, I if a question comes up sometimes like, you know, this seems like a scary block. Yeah. I'll say it was. 

It was a scary block, but not so much anymore. Yep. I think I think you're right. I think I think there are people that are still very scared of the paravertebral block. I think people are less scared of the rectus bony plane block. 

And I think as we start to improve the delivery and the confidence and the frequency with which we provide chest wall and abdominal regional anesthesia with these paraneuraxial techniques, I think we will see the Ganston described renaissance in the paravertebral block. I think it's gonna happen. I think it's gonna happen. I think the ESP block and the maybe the wrist block and the, you know, retro lamina, but all these blocks around this the the the paraneuraxis around the back, they're gonna kind of encourage folks to go deeper. Some people may never go any deeper because they don't need to. 

But I think we're we're starting on that journey. Yep. As we said, some regional anesthesia is better than zero regional anesthesia, I believe. Agree. Oh, hey, man. 

Listen. That was really fun. I enjoyed our deep dive into PVB. I hope hope you did too. Oh, dude. 

I totally loved it. I learned lots, and I think, you know, you might even have just pushed me that one step further to to kind of trying something a bit different, maybe doing Oh. An out of play approach. I keep getting the feeling that we might have left left something out or missed something. So, guys, if there's anything, you think we missed that we haven't discussed, you want us to to to get onto, please let us know. 

Yeah. For sure. Let us know. But, in the meantime, let's, wrap this up. So as always, please like and subscribe to our podcast from our usual your usual podcast provider, and, leave us a rating and a comment too. 

That really helps. The the the ratings are super helpful for us, guys, if if you For sure. Yeah. If you have a chance to to give us yeah. I feel like a car salesman. 

Please give us a a five is what really want here. And and where can they follow us? Yes. So what have we got? We've got Twitter. 

And at Twitter, we're at block it underscore hot underscore pod. We are also now at blue sky at b I l I h at b sky dot social. We're at YouTube at block it like it's hot. And where else are we, Jeff? Oh, we're on we're on Insta. 

Block it like it's hot with underscores. And don't forget the hashtag hashtag block it like it's hot or hashtag b I l I h. Please get involved in the conversations. I would love to have a big old roundtable Twitter conversation or x conversation, blue sky, whatever you wanna converse on about this and hear everybody's thoughts on paravertebral, the king of blocks. Absolutely. 

I have royally enjoyed speaking to you. I must say it. That's so bad. Really enjoyed speaking to you. Guys, until the next episode. 

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