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Hello, everyone. It's great to have you. Um, I am joined today by Doctor Ahmed. Elna Al Nadi and he is gonna be giving us a brief introduction about ultrasound guided regional anesthesia. As always pop your questions in the chat and er, Doctor Ahmed will get round to them as and when, ok, it might be during his talk, it might be after, depends on whether or not they're relevant to the talk at the time. Um As again, as always, there will be feedback which we would love for you to fill out. It's really important for you to fill out the feedback for our speaker. This is a way of thanking our speaker uh and giving them s some feedback and once you've completed your feedback, you will get your attendance certificate on your um med profile. All right. So without further ado, I'm gonna pass you over. Thank you, Ene. Right. Right. Good morning, everyone. Um, my name is Dr Ahmed Lati. I'm one of the consultant and this here in Manchester. And today we'll have a brief introduction to the ultrasound guided regional anesthesia. I know, um I understand you've got varying experience but I'll try to keep it as simple and as to the level as possible. Yeah, if you do have any questions, just pop into the chat as we go through and I'll try to answer them um as we go through. Ok. Right. So by the end of today's lecture, hopefully you'll have a better understanding about the basic physics of ultrasound. Um the different techniques and principles that we involved in ultrasound, guided regional anesthesia And this best practice for patient safety. And we'll have a look at a few of the most complete performed ultrasound, guided nerve blocks in anesthesia. All right, let's talk about the basics, the basic physics of ultrasound. So, what is ultrasound? So, um the audible frequencies of human hearing lies between 20 hz and 20 klotz or 20,000 htz. Anything below that we can't hear, which is um the ultrasound and then anything more than 20 kilohertz is the ultrasound. Um So it is high frequency ultrasound waves, um more than a 20 kg. And how do we generate medical ultrasound in clinical practice? Um We have the, it's a basic function of the piezoelectric properties. So, piece of electric crystals are certain types of crystals to which um if you apply an electric current to them, they would vibrate and then they generate um ultrasound waves and they work in both ways. So if ultrasound waves come back to them, they would vibrate and then they, they would generate an electrical current which we can measure. And um that's a picture of um one of the two discoverers of the piezoelectric properties. Um Pierre Curry and his wife um Marie Curie in their lab in Paris. So, ultrasound, this is a, a standard transducer that we use in uh uh anesthetics. So it's, it's, it's made, it's made of piece of electric crystals. And then when the ultra, when the electric current comes in, they vibrate and then they generate the ultrasound waves traveling through tissues hitting a target object, let's say a nerve or a blood vessel. And the ultrasound gets reflected back of it and then received by the transducer and then taken back to the machine through the central processing unit of the ultrasound machine to create this um two dimensional gray scale image that we see on the screen. Um just mindful that um the transducers um sends and receives um ultrasound waves. But they don't do this at the same time too. It sends an ultrasound signal and then stops and then waiting for a signal to be heard back and then does that again and again and again, it happens around 1000 times per second. So it's very, very, very fast. Um And that's why we can't see a real time image smoothly. The image is on the screen of the ultrasound machine at works at a rate of what 20 frames per second. So for the human eye, we can't really tell the difference but the ultrasound probe um spends more time listening or receiving than emitting or sending ultrasound signals. Ok. Now, the techniques of the basic techniques and principles of um ultrasound guided regional anesthesia first is probe selection. So we have lots of um transducers or probes in clinical practice. But the ones we use in anesthetics are the linear, the curve linear or the face array, the linear probe. Um so it varies depending on the um the frequency of ultrasound waves that they well the linear probe, it's a high frequency probe. So it sends uh ultrasound waves at 6 to 13 megahertz and it creates this rectangular image on the screen. Yeah, a curvilinear probe is a lower frequency probe at 2 to 5 megahertz. And it creates this kind of wedge shaped um image on, on the screen of the ultrasound machine. And then, then you have the phase array um probe which is a quite a lower frequency 1 to 5 megahertz. And we use that in mail in echo. Yeah. Now another function of ultrasound is what we call attenuation. And attenuation is as ultrasound goes through tissues, it loses part of its energy and that's what we call attenuation and it is um large proportion to the um frequency of ultrasound. So with high frequency there is high attenuation and with low frequency ultrasound waves, there is a lower attenuation. So sorry. So with the linear probe and like I said, it's 6 to 13 megahertz high frequency it and, and the sound waves lose much of its energy. That's why it has short penetration up to six centimeters. So it's ideal for visualizing superficial structures like nerves and blood vessels. Whereas the curve linear probe because it's a low frequency probe, um the at is quite less so it can travel deeper through tissues up to 30 centimeters. And we use that in abdominal ultrasound to visualize gross um um uh viscera like a liver or spleen. And then the phase ara pro because it's even lower frequency, it can travel even far further up to 35 centimeters. And we use that in echo. So, transthoracic echoes. So in short, high frequency probes have a better resolution but short or low penetration. Whereas a low frequency probe has gives us a lower resolution image but the advantage of higher uh higher uh penetrability. Yeah. Now orientation, how do you hold the probes? There are two ways of of holding the probes in an ultrasound guided region on statics, either an in plane or an out of play. So um no, sorry, um a short axis or long axis. So if we hold the pro perpendicular to the nerve, let's say we're visualizing here, the median nerve. So it the i the um ultrasound uh plane is perpendicular to the nerve, we'll see the median nerve as in a round structure like this, this is a short axis view. And then if we hold it parallel to the nerve. So in line with the nerve, so the ultrasound plane cuts through the nerve like this, it will appear in that way as a longitudinal structure, a tube kind of structure. And that's the long axis view. Yeah. Again, for blood vessels, it's quite the same. If it's a short axis appears like a round structure here. If it's a long axis, the blood vessel would appear as a long hollow structure. Yeah. In terms of needle approach, there is an implan or out of plane needling and that's relative to the um position of the needle in line with the ultrasound plane. So if it goes um next to the um well in parallel to the ultrasound beam, and that's an implan needling. If the needle is perpendicular to the ultrasound beam, it would appear on the screen as a round dot here or bright hyper colic dot And that is the out of plane needle and just imagine this and the ultrasound plane um that comes out of the probe is it takes us a thin slice of tissue for us to view. And the thickness of that is around one millimeters and that's the size of roughly your credit card. So, trying to align the needle and the ultrasound beam right on spot on and to be able to visualize the needle requires a lot of manual and dextra and hand eye coordination really. And that comes with the skill of that skill comes with more practice of ultrasound and needling techniques. Now how to get good views. Well, whenever you, you you you want to visualize any structure, ideally, the ultrasound beam should be perpendicular to the structure, you're you're trying to visualize. So for example, if you have this ultrasound, sorry, the this um um yeah, so plex needle, the ultrasound beam comes straight from top and because it's perpendicular, it, most of the ultrasound waves will just bounce back off to be received by the ultrasound probe. And hence, you have a clear image of the needle. Whereas if it comes with an angle and the ultrasound waves come um down straight down there, part of it will be bounce it off and reflected off um the needle in the other direction and it won't be received by the probe. That's why you get a faint image of the needle. So if you want to visualize a nerve or a needle or a blood vessel or whatever, try to keep your probe as perpendicular as possible to the structure you're trying to visualize. OK. Now, probe movements, we have different uh movements uh for an an um the ultrasound probe. And you can remember it by the mnemonic part. So P A RT pressure, so you're applying pressure with the trans user alignment or sliding, that's a two dimensional sliding of the probe along the surface of the skin and then the R is rotation yeah, along its long axis and then tilt. Uh we either tally or um cranially OK. Artifacts. There are lots of artifacts that could develop on the ultrasound image that you see on the, on the machine. But we'll talk about the two of the most common artifacts that we encounter in clinical anesthetics. One is we what we call reverberation and reverb happens when an ultrasound on the ultrasound uh waves hit a hardly reflective uh structure like a needle. So um ultrasound waves come from the probe, they hit the needle and they bounce off back to, but they keep bouncing back and forth between the needle and the transducer. And the machine interprets this as if there are different needles underneath because the second wave that comes had taken longer at a longer time to um to reach the probe. And the machine understands that is probably a quite a deeper structure. And then the second reverb is another deeper structure and a third reverb another. But this is just an artifact and it's very common to see this during a needling techniques. And then the second artifact is what you call acoustic shadowing, acoustic shadowing happens when the ultrasound essentially cannot penetrate through a certain structure. So bones, for example, because ultrasounds cannot travel through bones. So anything behind the bone is kind of hidden. Yeah. And and there is a kind of a shadow as you see in these um images. Yeah, behind the ribs. This was this is um what we call acoustic shadow. This is part of the um um ultrasound ultrasound of the lung, um pleural lines and this, this should be the lung tissue. But again, a anything behind the ribs is just hidden by the ribs. Ok. All right. No safe practice of um ultrasound techniques. You should always have a safety checklist. Well, depending on whereabouts you're in the world and the policies and protocols, but always have the safety checklist. And in my experience, I take a routine preop assessment and procedural consent. Yeah, from patients and then ensure you have a sterile equipment, a good light source IV access monitoring. So standard monitoring, resuscitation equipment should be readily available. Have a trained assistant next to you and you'd have the facilities to convert to a general anesthetic at any point. Ok. In the UK, we have this another safety net which is the stop before you block moment. So this is all endorsed around in the NHS. And it's endorsed again by the Royal College of Anesthetists and the Association of Anesthetists. And um it's basically a stop moment right before inserting the needle. So let's say you prep the patient you've admitted. Well, you've checked in the patient, you positioned prep the area and you've scanned, you're ready to um do the block. But right before inserting the needle, you need to make a stop before you block. And this is to ensure you have got the right patient for the right surgery and the correct side of surgery right before the needling. And why is that is because if you do this stop before you block moment, like for example, when you've checked the patient and then you have a, you, you might be distracted by a discussion with the patient or a colleague or something. And then when you come back and do the block, you might switch sides. So it's very important to do it right before you insert the needle, not before that. Well, uncertainly, after not after that right complications. So potential side effects from ultrasound, guided regional statics. Well, we've got some general or generic complications that can happen with any uh block and then some specific ones, the general ones are well vascular injury, you might the blood vessel infection if you're not practicing good A T techniques. Um Obviously, nerve injury that's quite um unusual with the ultrasound use. Um local anesthetic, systemic toxicity or last or failed or inadequate block that applies to um all nerve blocks. Really? Yeah. And then the specific ones. So pneumothorax that happens that that could happen with um a supra nerve block. So things around the the dome of the pleura. Really? Yeah. Um accidental spinal or epidural injection, visceral injury. For example, if you're doing eye blocks or tap blocks, you might hit the bowel postop the injury to head limp. Obviously, I always give, I always give my patients um well, head of warning that um they might, they will not feel their um for example, the blocked area, their upper limb, for example, in a super block, they won't, you won't be feeling the lymph for up to 24 hours. So they might, they should be careful, for example, not to lean on warm surface because they might get burnt without even noticing because they're not feeling their limb. Ok. Methemoglobinemia is the one specific uh uh side effect of um prilocaine toxicity. It happens with either you've given um an excessive dose in a tiny patient or um within a normal dose. But again, in a petite um uh patient, um the local anesthetic systemic toxicity. Well, I won't go into the details of it, but here in the UK, we have the A GBI safety guidelines which um gives us detailed description from recognition to identify the signs and symptoms of local anesthetic toxicity and then the immediate management and then the um and resuscitation and then um even the detailed doses of um the 20% lipid emulsion that you need to give to your patient. And finally the follow up, how would you follow up these patients and counseling them and um and giving them the medical bracelet or uh and things like that right now, um let's have a look around the, a few um examples of the ultrasound guided nerve blocks. Well, in, in um this in anesthetics, we have the head and neck, the eye blocks, um, the upper limb blocks the chest wall or the truncal blocks, the neuro blocks the upper limb and distal limb blocks, lower limb blocks, eye blocks. It's kind of a lot of blocks really that we can use the ultrasound to, to do. And that's really beyond the scope of this lecture. But, um, I'll try to tell you about a few of the common, commonly used ones and the straightforward ones that you can start learning, um, faster I'd say. But which one, which blocks do you choose for your patients? Well, um, this, um, this um, table will tell you, um, which blocks you you need to do for which kind of surgeries, um, um, orthopedic surgeries. Really. Yeah, for both for upper limb and lower limb uh surgery and then the abdominal and thoracic. Yeah. So let's say, for example, a carotid endarterectomy, a cervical plexus block is your choice. Um, breast is, is a part of vertebral or now we have the pax one and two Cerra plain block depending on the surgical approach. Um, and so on. Yeah. All right. Let's start with the upper limb blocks. We have the interscalene approach, the supraclavicular, the infraclavicular axillary, the distal nerve blocks and the wrist blocks. And this depends on where you're attacking the brachial plexus at which point if you're, if you're starting at the roots, uh, that's the interscalene, if it's the trunks, it's the supraclavicular, if the axillary is probably the terminal branches. Yeah. And why we need to block it, why do we need to block it through different levels of the brachial plexus because of the sensor area that's covered at each point. So for interscalene, for example, um you, it's ideal for shoulder surgeries. Where is the distal limph and the axillary, for example, is for lower forearm and wrist blocks. Yeah. Um we'll be talking about the interscalene and supraclavicular um approaches as well as the uh distal um upper limb and nerve blocks today. And in each block, we'll talk about the indications. How would you position your patient and the specific uh complications for, for each of these blocks before, before we start for all blocks, I'll give you nine steps. So um right before your injection of local anesthetic. So say you, you've scanned, you found your uh and you inserted in the needle. Um uh you're ready to inject your local anesthetic right before you inject, reduce the probe pressure and do a Doppler a color flow Doppler. And that's to identify any potential aberrant blood vessels that you might find in the way. And why would you reduce the pressure because there might be veins that could be easily collapsed or squeezed underneath the probes. If you release the pressure, you might be, you might see any um um vein in the way. Yeah. And then after an injection of the local anesthetic, do a dynamic scanning. So, dynamics So in, in this block, for example, you need, it is still here and you've injected the local anesthetic and dynamic scanning is essentially scanning, right, proximal and distally to where you've injected your local anesthetic. And in here you'll find the, the nerve surrounded by a puddle of the jet black local anesthetic. You see that it's a very characteristic sign and we call this the donut sign, but it's not necessarily um you can't always find this sign. It's not, it's not a, a mandatory sign. But if you, if you find this, then it's one and good. Yeah, that means your nerve um is all surrounded by the local anesthetic and the block will most likely be successful. Ok. Um Another thing um this is an Interscalene and this is the median nerve block. And can you see the difference? Is there any difference? So I I'll point out this is the inter, so this is the anterior scalene, middle scalene muscle and this is the interscalene uh uh well, brachial plexus, this is the brachial plexus nerve roots C five C six and probably C seven here. And in the mid forearm, this is the median nerve in the mid forearm. This is the flexor digitorum superficialis and this is the flexor digitorum profundus. And that's the median nerve. Can you notice the difference between these two neural structures? I can't see the right. Um You see this is quite dark, it's like an hypo echoic dark structures here. But this is a very bright hyper echoic structure. And why is that? Well, it's because uh more approximately the nerves or the neural structures are, are um are all composed of um well neural tissue. But as they go distally as in the media nerve, for example, it's mostly connective tissue. That's why the uh with the connective tissue, it looks brighter whereas as you go centrally or proximally if they're still darker because they've got loads of nervous tissue in there. OK. So that's very, very normal. Yeah, that's what we expect, right? Let's talk about the inter scaling though. So the inter scaling it's indicated in shoulder surgery. Yeah, because it covers mainly the shoulder area. Um um and it's got it spares the nerves, it really covers the upper um two roots. So C five C six, maybe C seven nerve roots. Yeah. Patient should be positioned with head up. Um the sorry supine with the head up and the head turn to the contralateral side. Yeah. And on the screen, for example, we'll see that's what we, what what we look. So you'll put the probe at the level of the cricoid cartilage. Yeah. And then starting scanning up and down until you visualize this view. Anterior scal middle scal and the nerve roots. The brachial plexus nerve roots in between. Yeah, anterior sca middle cal and in between, I'll come back to the complications later on, but let's have a look right. This is a view that you see with the ultrasound. Again, anterior scalene, middle scalene, this is your blood vessels nearby and the block needle is coming through there. Um Another tip I'll give you um I always aim to the six o'clock position. So five or six o'clock position in, well, most blocks really. Yeah. Um because it ensures that your local anesthetic really surrounds both sides of um of the neuro structure. They're trying to do um in some, in some big um blocks like these ones because you've got a number of neural structures, you might come back and do it on top as well at the 12 o'clock or 11 o'clock position. Yeah, let's have a look. So C five C six needle see. Yeah. Through the middle scale, the anterior scale needed right in the trajectory. I'm gonna stop this here in the trajectory. Initially, the, the, the, the C, the C um C six was in the way. Yeah, of the of the needle trajectory. That's why um um redirecting your needle away from the nerve structure really prevents um neural injury. Yeah. You see, do you feel that pop? Yeah. And then yes, injecting local, you see the unzipper of the fascial planes between the ANCA and the neural structure here. See this is very classical, very ideal. That's really what we want to see. Yeah. Shall we say that again? OK. C five C six redirecting going six club position. Yes, puncture it and follow up, right. Specific complications for the inter sca block is um OK, we just go back. It's the nerve block because it's really, really close to the and depending on the volume of the local anesthetic you're injecting. Most likely it will spill over the fre nerve, which comes from see, 345. So around 100% of patients really, I get a nerve block, I get a phrenic nerve block or a hemi diaphragmatic paralysis with these blocks. That's why it's, it's absolutely contraindicated in contralateral ske, for example, because they will just have both Reni uh blocked or on one side. It, it could be a relative contraindication if um in patients with severe COPD or who are oxygen dependent or even a slight drop or in their um um uh in their um respiratory efforts would cause a significant uh drop in their ventilation and oxygenation. Yeah. Uh intrafusal injection, obviously, because you've got nearby structures and like I said before, you inject, just make sure you do a color flow Doppler to make sure you've got no crossing um blood vessels in the way and the epidural spread because if you go a bit too proximally, you see that you're quite the all the spinal nerves that come out of the intervertebral foramina, they have an epidural sleeve surrounding them. It's a short sleeve. But if you go too approximately with your needle, if you, you might hit this epidural sleeve and all the organs that you're injecting, uh, or part of it might go epidural which you don't want to really do. Right. Any questions so far? No, bye. Mhm. No. A supraclavicular block. It's a bit more distally through the brachial plexus block. It's at the level of the trunks. Yeah. As they cross over the first rib. Yeah. So, the brachial plexus crossing over the first rib in here. That's the first rib. Well, it's been cut but it should be here and it's right next to the subclavian artery again, crossing over the first rib. Yeah, it's ideal for um um surgeries on the lower arm, forearm and hand. Um Some, some people call it the spinal of the upper arm spinal anesthetic because it essentially covers or Anestis the whole upper arm from mid mid arm to lower down. Um So it's useful for essentially all surgeries of the upper limb really apart from shoulder surgeries and just be mindful. It spares the upper medial aspect. Yeah. You see, as you see in the upper medial aspect of the arm that's covered by the pectoral and the intercostal brachial nerves. So any surgeries in here um won't be covered. Yeah, but for example, shunt surgeries or anything in the forearm fractures or, or plastic surgeries or anything in the hand would be covered with a supraclavicular block positioning exactly the same like the interscalene. So patient supine, slightly head up and uh the face turn to the other side and um because I'll come back to the complications again, right? So let's have a look um with the Artus image that you want to see um is with the ultrasound. So you put your probe in the supraclavicular fossa and you scan well with a little bit of tilt, not much sliding. Yeah. So a little bit of tilt, you would be able to see this view. So this is the first rib, the pleura the artery and this classically described as a bunch of grapes. Yeah. Um That's your um um supraclavicular um brachial plexus. Yeah. Um again, different view. So the first strip, the arteries sule and the classical bunch of grapes in here. This is um the first rib you always want to see the first rib under underneath. So try to attack the block right as it crosses over the first rib because the first rib provides a safety boundary from the underlying lung and pleura. Yeah, that's why the complications here. It's a pneumothorax is one of the recognized complications of a supraclavicular block. Yeah. And obviously a vascular injury because or vascular injection, intravascular injection because you've got a very nearby uh big artery, right. Let's see how this looks. This is just a switch if you want. This is the medial lateral, the artery and the brachial plexus around here. Yeah. Needle coming from naturally. Yeah. Again, aiming to the 60 clock position just underneath and once we feel the pop Y and we inject the local anesthetic again, very nice unzipper in here with the local anesthetic and spreading on both sides. Yeah. And because this is a big structure, you might want to, you know, withdraw your needle a little bit, make sure it's all covered from underneath and on both sides and even you can pull out and come on top. Yeah. Some I the and it will all be surrounded with the local anesthetic and you'll get a successful block. OK? Especially in these um um blocks, the brachial plexus blocks. Always remember um to do the Doppler uh the color flow Doppler before you inject your local anesthetic because um like I said, you might find a few blood vessels here and there that you can't really see um uh with to send an ultrasound, right? Any questions before we move on? OK. I think it should be straightforward. Yeah. Right. Distal upper limb nerve blocks. These are um indicated for hand surgeries or as rescue blocks. So for example, you've given a block, an axillary, for example, for a wrist surgery, a dubi for example, and then it's just the surgery is taking longer than you'd expect. Then you don't need, you can't give a really um another axillary, but you can top it up with a median, for example, a mid forearm, median nerve block in here. Yeah, it's, they're very, very useful really in these kind of situations. Yeah. Um For all them, the patient is the arm is supine and abducted. And the recognize complications here is that um either intra muscular injection because there is a nearby blood vessel or obviously a nerve injury because your needle is just hitting one, well, not hitting it is just very close to one single peripheral nerve. Right. Let's start with the median a four arm median nerve block you usually do it with. So the um with the probe in a short axis view, this is the previous picture we've seen. So flexion, flexor digitorum, superficialis, median nerve and flexor digitorum profundus. So the nerve is sandwich in between the two muscles. Yeah, let's have a look. This is your artery, see pulsating and hang on. This is the median nerve looks like um hyper echoic um Raspberry uh kind of structure. Yeah, you'll come in once you puncture the fascial plane. Mm Yup. Yes. You see this um you feel this pop. Yeah. And then just 35 mils in there should be more than enough. Yeah. OK. Um For the ulnar nerve. So again, short axis view on the medial aspect of the forearm or the upper forearm, you never do it at the medial epicondyle because the just a tiny volume of local anesthetic might squeeze um uh the the ulnar nerve because there is this is um a tight compartment behind the medial condyle and it might cause a nerve ischemia or nerve injury really? So we don't, we never do it at the medial epicondyle. So we do it a little bit distally in the upper uh forearm. OK. And that's really how it looks. We'll see again, very bright structure in between the muscles. Yeah, na comes in from major to lateral and then yeah, again, 35 mils, you see how, how, how it looks, it looks like a raspberry. Really? I like to describe it that way. Yeah. OK. Three or five mils. The local anesthetic. Yeah. Um surrounding it from both sides. Yeah. OK. With this um with these peripheral nerves because you're blocking just one single nerve, you don't need much volume. You don't need to put a gallon of local anesthetic. Unlike the proximal, the supra Lear inter where your volume would be 15, 20 mils. Well, probably less if you're really confident and with experience 10, 15 mils could be just enough. But um for peripheral nerves you can, you can just 34 mils, five mils would be more than enough. OK. And then with the radial nerve, the radial nerve is not blocked in the forearm. It is blocked in the lower arm. Yeah. Um laterally, that's the kind of the position you want the patient's arm to be in. And the view you see again, a short axis view. Uh This is your humerus. Yeah, under the and between the biceps and the triceps, your rate in there will be found this way Yeah. And that's the needle pulse. Let's have a look. That's, that's your, um, on a radial nerve again. 345 mils is enough. Ok. Yeah, that's it. Yeah. Right now, let's move on to, uh, lower limb blocks. Any questions though, before we carry on, they're very quiet, aren't they? Yeah. Yeah. Must be too easy. I'm doing a job where no one really understands anything. Right. Ok. Excellent. Um, lower limb blocks again, lots of blocks and these are just a few, there are a few other, um, um, um, well, highly specialized specific blocks, but the ones we're going to talk here today is the femoral and the ankle block. There is a lateral femoral cutaneous nerve, fascia block, AUC canal, popliteal sciatic and ankle blocks. These are the very standard, um, kind of blocks. Yeah. Uh, let's start with the femoral nerve, femoral rock. So the femoral nerve, uh, let's have a bit of anatomy in here. Uh, loss of the femoral triangle below the inguinal ligaments, um, arranged. Um um in uh, the femoral nerve from me to lateral, the, sorry, the femoral vein, the femoral artery and the femoral nerve. So, van, yeah, vein, artery and nerve, um, the arch and vein are in the femoral sheath, whereas the nerve is outside of the femoral sheath. Yeah. Um, the ideal position you want to, um, block your femoral nerve would be at just at or above, right above the bifurcation of the artery and why is that? Because it's exactly at the same point where the nerve uh starts to divide into different branches. So instead of uh so to ensure successful block, uh you instill your local, stick around a big chunk of the nerve in here instead of trying to um inject it a bit distally where you might miss one of the branches. Yeah. Um Indications. Well, for anterior thigh surgeries like quadriceps, for example, muscle repair, uh femoral or knee surgeries and for postoperative analgesia after knee arthroscopies and um uh knee replacement. Yeah, patient's position with supine with the legs extended. Yeah. And um the common complication. Well, the specific complications for this block is um intravascular injection because you've got really nearby blood vessels and um intramuscular injection which would um present as well inadequate or failed block. Bye. This is the view you're gonna see with the ultrasound again. Short axis view, subcutaneous tissue. This is your fascia, atta fascia, ilia, femoral vein, femoral artery and the nerve is in here overlying the ileos muscle. Yeah, that the view you wanna see. So that's the femoral nerve, the artery, somewhere in here. You could notice the pulsations but it's not right spot on the image. I do apologize. Yeah, that's the artery and that's the nerve and you see the injection of the, this is a bit of hydro dissection, you see that. So before reaching the nerve, if you're struggling because all the fascial pains are really squashed in and squeezed. You might do a hydro dissection with just normal cell line. You don't want to waste your local anesthetic. Yeah. Oh, sorry. Yeah. See, bit of hydro just to open up the space and then you can inject your local anesthetic in there. Yeah. Just be careful not to um, advance the needle too much because the artery is really in the, the trajectory of the needle path. Yeah. Right next, the ankle block, ankle block is um indicated for foot and ankle surgeries. Patients is positioned supine with a leg extended and hanging off on a pillow of the edge of the bed as in this picture. Yeah. Uh specific complication as well. Not much apart from intravascular injection because you've got uh in with some of the nerves. There, there are some nearby blood vessels. Um Right. So what nerves do we block? There are five nerves uh for an ankle block that you need to cover. Yeah. Um I'm thinking. So this is the superficial peroneal. Yeah. And the deep perineal, the nerve, posterior tibial and the softness nerve really uh next to the long softeners vein. So there are five nerves, all are branches of the sciatic nerve except the Soha this one. It's a uh it's a terminal branch of the femoral nerve. Yeah. And then um um uh anatomically, there are three of them are superficial and three are deep and superficial, deep relative to the um flexor retinaculum in here. Yeah. So there are just the skin subcutaneous uh tissue, they're line with rot underneath the skin. Really. Yeah. Easy way of remembering it. So all starting with an S are superficial. Yeah. So the so nerve, the superficial perineal and the the and then the deep uh nerves are, is the deep perineal and the tibial nerve or the posterior tibial nerve. Yeah. Right. Um All these blocks, well, the ankle block is can could be done with a landmark technique with a really um uh high rate of success because the superficial nerves are blocked with just with a simple field, a field block like a local uh anesthetic infiltration, subcutaneously um on on the front, on both sides of the medial mali. Yeah. Uh the deep perineal again could be a landmark technique or you could visualize it with the ultrasound. But I'm gonna talk here about on the posterior tibial nerve, which is um which is easily visualized with the ultrasound. Yeah. And because of its importance because it's got very close relation to the um artery, the posterior tibial artery and vein, right. This is the look at the view we're gonna have uh with the ultrasound again, a short axis view, median mas the tendo achilles and that's this kind of arrangement. And which one is the nerve? That's the tibial nerve. Yeah, posterior nerve. Um it's this arrangement is um is kind of characteristic really. Yeah. Uh To be honest, posterior a flexor, digitorum longus, um the posterior tibial artery and nerve and then the flexor ha Lu easy way of remembering this is again another Minne here, Tom Dick and Harry. Yeah. Tibialis, digitorum artery, nerve and halls, lungs. Ok. All right. Let's a look at this. Sorry. Hang up. No. Now, without the, obviously, if you have a look at the, the um ultrasound image, you might be confused. Ok. Which one? Ok. That looks as an artery. Yeah. But could this be the nerve, could this be the nerve? Which one? Which one is the nerve if you get confused and his way of doing of um of uh I didn't find the nerve is just tracing it down uh sorry, tracing it proximately through the along um the lower leg, the tendons will disappear into the bulk of the muscle. Whereas the nerve will still be the nerve. Yeah, let's have a look. Yeah. So tracing it up, you see now that's a big chunk of muscle here, the artery, but the nerve is it still a nerve? Yeah, right here. Oh, that's a muscle. Yeah. So all the tendons have disappeared except this um bright hyper co structure next to the artery. Yeah. Shall we see that again? So all the tendons in here, just the nerve just stop muscles start to appear but the nerve is still there. Yeah, perfect. All right summary right. Ultrasound guided regional studies is a mix of science and art really. Um you need to have a be a good understanding of basic physics, um anatomy and so no anatomy of the structures you're, you're targeting um combined with safe practices. Um uh to make sure you've got the safe and successful block again with the art of manual duty and, and um um uh eye hand coordination that comes in with hands on experience. Thank you very much. Thank you. OK, everyone. Now's your chance you can pop your questions in the chat because you know, most people know who have come to medical education events know that I am not medical so I can't help them good. And so we'll give them a minute to pop their questions in the chat. Thank you very much for your talk. That was great. I don't know how you learn to see that, that imaging, that black and white, how you can make things out. I just, that's a skill within itself. It's just like, what's he showing? Oh dear. Remember that when I had an ultrasound as well? It was like, where's the baby put it in? There we go. We have a question in here. Does regional block mean different kind of blocks or is it just spinal and epidural? Oh So regional regional anesthesia is anything apart from um general anesthesia? So we have the what these are peripheral nerve blocks, spinal ural, we call it neur axial blocks or neur axial anesthesia because it's um along the axial skeleton. Yeah. Um but both are um could be included as a regional anesthesia but usually in common practice, a region refers to the peripheral nerve blocks, spinal or epidural or just spinal epidural. Yeah, perfect. I've got another question here. What is your view on performing femoral taps and or femoral cannulation? Can cannulation example? Oh, my hemodialysis in resource limited settings. W slash O ultrasound guidance without, without ultrasound. Yeah. I'm not sure what you mean by the femoral taps. Um Is it just femoral um um artery or femoral vein cannulation if you don't have the ultrasound? Um Obviously it is still, it is a still um well, um a manual skill. So um if you don't have the ultrasound and you know, the landmark technique for um for um doing a femoral art femoral vein cannulation, you can really still do this because if you want to, if you have to do it, you have to do it if you don't have the ultrasound, but it's just the ultrasound now is an added uh safety practice. It ensures you've got better success rates, uh less complications, less side effects. Um So it's really, really useful. But if you don't have the ultrasound, then you have to do it for your patient. Then yeah, there's um just follow the standard protocols really and the safety um steps and then um yeah, you're good to go. Perfect. Thank you. Does that answer both those questions Um Mohammed has asked, can we get the slides? Are you happy for me to share the slides on? Catch up? Ahmed. Yes, you can. Mohammed. I will pop them on, catch up along with talk. Does anyone else, does anyone else have any questions? And, er, for a ALA and Ahmed, did we answer your, did he answer your questions or is there something else you want to add? I'm hoping people are frantically typing this. Yeah. Um OK, so Ahmed asked for anesthetic blocks in general. Are there any resources tailored specifically to improve your skills or would you say that experience is the best? Well, OK. Well, of course, hands on experience is really, really helpful. Um Well, you say if you're good at, well at playstation video games and you'll be good at ultrasound and laparoscopy. It's because you have this hand eye coordination really and you can really draw a mental image, a 3d image of a two of the two images they see on the screen. We don't have 3d ultrasound. Well, in for anesthetics. Um But um I think I can share with you a few um resources. You can go to the, the New York School Regional Anesthesia website and there are a few of the youtube channels that you can um that's really, really helpful in in simplifying and going into details of each and every nerve block I can share it on the with. And if you, you're happy to share that with the, with the audience. Yeah, that would be really helpful. Yeah. So it's a really a a combination of basic knowledge, um reading and watching some videos and then getting and doing a hands on experience, hands on experience is really, really, really important. Yeah, because not all patients are really um classical like the views you see on the videos you might get patients come in different sizes and shapes. So um you might find a straightforward scaly in one patient is really difficult to visualize in one in another patient. So um experience is really important. Perfect. I don't know if I like this question on Ma Lola. Do you feel the pop when the needle goes in and what gets popped? Yes. Yeah. Um Yes. So um again, it comes with experience but it um the ultrasound needles are short beveled needles, they're not like the sharp um intradermal needles that we used to inject, for example, they're short beveled and they're designed that way because you don't want them to slice through Tiss, but you want them to feel the fascial planes as you go through. Yeah. If and again, if you, what you feel the pop is the fascial place. This is usually, for example, a prevertebral fascia or the in the femoral nerve is the fascia lata and then the fascia iliac. Um So these because they are quite fabulous structures and with a short be needle, once you go through them, you'll, you'll feel this kind of pop. Yeah. Um Sometimes it's quite difficult in some patients. For example, is if it's quite difficult to uh pop the needle through. So a fine hand rolling technique. Yeah, if you roll the needle that way you'll be able to puncture through the um um structure you want to puncture. Yeah. Does that answer your question? Is there anything that you could practice at home with? I'm also practicing at home. Is there anything that would be similar that you could do? Um Well, we have um there are some mannequins, you know, um or um models for the models of the arm or the back or even the lower limb. Um II, I can't think of um I'm sure I'm sure there will be, but I can't think of anything. That was just my question. It wasn't, that was me. And then um any advice to get more experience as a junior? Uh Yes, start with shadowing someone has experienced in, in this um start with the basic um um straightforward blocks. Don't go into um complex stuff. So I would recommend peripheral um the distal um upper limb nerve blocks, the median radial ulnar, usually the median is very easy on the ulnar. Yeah. Um lower limb again, go with this simple stuff like the femoral or the fascial block. These are quite straightforward and easy to do blocks once you develop that experience and you could easily defund the nerves, you can go to the next step, which is, for example, the interscalene or the supraclavicular and usually the truncal blocks required are we call it advanced blocks? That's why I didn't include them in the lecture because they're quite really advanced and the, they're very close to critical structures. So I didn't want to add complexity to the lecture, but that's would be your third step as you've, if you've mastered the previous um blocks, the simple blocks and then you're going to the more complex ones that would be really helpful, shadowing um someone or learning from someone who's expert in this. Yeah, is also another um a way of getting um um mastery with this. Yeah, perfect. Does anyone else have any further questions or anyone that's asked a question? Did they want to elaborate on anything else? As always? Like I said, your feedback form will be with you at 11 o'clock in your uh email inbox if you could fill it out. Oh, here we go. I got another one in terms of neuro axial block, epidural slash spine, which did what, what determines which to go for. OK. Um Right. Uh a spinal epidural. So the difference between a spinal or epidural, the spinal is a single shot injection. Um and we call it an intrathecal injection. So you go through the um um inject into the thecal sac. Yeah, as into the CSF surrounding the spinal cord where the epidural as the name implies is epidural is injection as superficial to the ure before you puncture. The Yeah, and this is a continuous catheter technique. So with the spinal, like I said, it's a single shot injection, you inject and come out, you inject with the needle and come out. Whereas with the epidural, there is a tiny catheter that stays in the patient's uh back and you again put the dressing on it, it can stay up to 72 hours. That's uh three days uh where you can top it up with either with local anesthetics or on a continuous infusion of a local anesthetic through the epidural. Um because the spinal um goes through the um jura um you need to be careful that you're doing it at a level below the end of the spinal cord. So the high in, in adults, it ends at L1 or the L1 2 interspace. So spinal is only done anywhere below. So we start usually at L4, 5 or L3, 4. Yeah, the injection and you can go a bit higher if you, if you're struggling with something. Um but the highest is your L2 3. Yeah, an epidural because you're away from the, you're not into the CSF there is cervical epidural, there's thoracic epidural lumbar epidural. Yeah. So you could inject all the way through the um um along the vertebral column. Yeah. Um Another factor is the duration of surgery because this one is just a single shot injection, you inject your local anesthetic, uh, you're, you're limited by the duration of the local anesthetic that you've injected, which is usually it's the, um, bupivacaine, the heavy bupivacaine and that lasts anything between 2 to 3 hours. Yeah. And because the epidural, like I said, is a continuous infusion. You can run it or you can give a top up of local anesthetics. Um, um, you're not guided, you're not, you're not limited by any time. If surgery takes six hours, seven hours, you can just keep topping up your, um, um, epidural. Yeah. So, um, time the duration of surgery, um, why the indication of surgery? Um, and also the, um, level of block that you require. So, for example, spinal, the highest you can do is, um, um, t eight. Yeah, in Cesarean sections is t four ideally. Yeah. Um, so anything abdo not saying belly button and down below, it's either for the spinal with, with an epidural, like I said, you could do thoracic epidurals. So you could do a bit higher with the block. Yeah. Um, does that, um, does that help and do they both do the same thing? Like I've had an epidural? Well, I'm assuming it was an epidural when I was giving birth. So, it's just like, do they do the same thing? You just basically can't feel it? Yeah. Exactly. Yeah. Yeah. Yeah. Yeah. Yeah. Right. Um, did you, um, the, the, the the one of the differences of the spinal and epidural is that the block within a a spine is quite intense. So there is intense motor block. Um you see you can this a good sensory block and in good motor block. So you can't move your legs and you don't feeling anything. Whereas with the epidural, we can play with the concentration of the local anesthetic. So if we give you a dilute um concentration down the epidural, um you can move your legs but you're not feeling anything and in, in labor, for example, some, some hospitals do what we call a walking epidural. So, walking epidural is a very dilute concentration of the local anesthetic that you're not feeling the labor pains, but you can still walk. Yeah. So um so yeah, there you go. I don't think I got that I can move my spinal because I couldn't move a muscle. So does anyone else have any more questions before we uh this up? You gonna have to be quick. Uh Nope. Just well, thanks so much for this doctor. This is great. Thank you. Thank you. I think that's it. So, what I'm going to do is I am gonna close a call now. Ok, everyone. Um We have another event this afternoon and then we've got two events on Friday if you want to catch up there. Ok. So we will say goodbye and we will see you again soon. Take care