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This on-demand teaching session is relevant to medical professionals and will provide a comprehensive instruction in the fundamentals of using ultrasound in a clinical setting. The session will be divided into two sections - the first part will cover the physics and technical aspects of ultrasound, and the second part will cover its clinical applications. Participants will have the opportunity to learn about the physics, how the ultrasound works, as well as the different parameters such as sound propagation, reflection and attenuation. Additionally, there will be multiple choice questions and thankful messages at the end.
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Learning objectives

Learning Objectives: 1. Explain the physics underlying ultrasound scans and how they work. 2. Describe the acoustic impedance of different tissues and how it affects sound propagation. 3. Identify the different types of reflections on an ultrasound scan. 4. Discuss the attenuation of sound waves and its effects on image quality. 5. Explain the components of piezoelectric effects and their role in sound wave transmission.
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The following transcript was generated automatically from the content and has not been checked or corrected manually.

OK, let's start. Um And I got, so which one do you, do you want the fundamental physics or the other one? Uh your microphone is closed, the physics first please. This one. OK. All right. So uh let's talk. Um officially uh good afternoon everyone. Uh This is another one of our um the next one of our teaching uh program. Uh This will be a two part um um teaching session basically by mister who is an emergency general, uh an general surgeon and in uh abdominal wall, upper and bariatrics. And apart from other things, he's uh teaching the music course for esters who who is basically an uh ultrasound for surgery course. Um And this will be the, the, the, this part will be the theoretical um part. And in the next, next week we'll have the practic as you can understand. Uh it will be uh in person only uh for the members of the department. I highly encourage you to attend the co the uh I think it's like a good induction into ultrasound, which will be the stethoscope of the future, a very important skill for any surgeon regardless of um focus. And subspecialty. Uh Miss, um, I'd like to take the stage start. Yeah, thank you very much. Um, well, uh, ultrasound scan. So probably the, the first question you will, you will have when you see this presentation is, uh, why I should know about the ultrasound scan. I'm a surgeon. I'm not, I'm not a radiologist. Um, so, uh, I had the same question like you, uh, the same thoughts about you when I started doing this ultrasound scan course a long time ago. Uh And uh from the worst fun of ultrasound scan, I became the best one. Uh And there are many, many reasons that you will understand in the process. Unfortunately, uh Before saying uh the details about uh the uses of ultrasound scan in clinical settings, we need to go through the physics and uh some uh uh more details about how the ultrasound scan works. So uh the context of this presentation will be first of all that sometimes the physics nob And in the end, I will try to make it a little bit more spicy by giving you some multiple choice questions. Uh And in the end, some thankful messages. However, this presentation will not finish like this, then we'll have a second presentation with uh clinic. So let's go to the next uh slide. Um So ultrasound scan is the sound and we need to have this in mind. Of course, we are not uh we are doctors, we are not uh uh dealing with physics all the time. I think the last time we dealt with physics was in high school. Um and some in university because we do some medical physics. However, it's a little bit difficult to understand uh about some uh terms and how, how does this work? So the easy way to understand is like ultrasound scan is the sound uh that uh goes like waves outside the source and then uh hits some subjects and turns back uh as the same form of sound and it is going to the receiver. Uh And that means we will uh the receiver will give us some imaging. So let's go to the next slide. Uh The the ultrasound scan actually is coming out is the, the sounds coming out of this probe that you can see here on the left side of the screen. Uh then uh using the piezoelectric effect, then goes on the patient body and then turns back to the machine which is like a computer. Uh There are several type of machines, you will see a one or a big one like a tower uh where this sounds it been um um going inside the the electric uh the electric machine and becomes like a um data and a picture. So let's go to the next one. Um Yeah, panels, next, next slide, please. OK. Uh So this effect is a little bit tricky to understand. But uh this is how the uh the ultrasound can work. So there are normal crystals inside this uh this probe uh when there is an electrical charge and causes these crystals to be uh compressed and uh uh like extended like in this screen you can see here. So all of those signals are interpreted with uh those effects which is called Petric effect and then go back to the probe and it becomes like a, a photo or a picture or a video. Next slide, please. Uh The acoustic impedance is uh one of the terms you will see, it's quite difficult to understand. But uh you need to, the easy way to understand is if you have AAA sound that goes between two types of surfaces. So one of the surface has a different density and the second surface that has a another different de density I gave you this example lower down, which is uh as you can see the liver and the gallbladder. Uh can we imagine why uh we say about gallbladder wall thickening? Uh And this is measured where the liver is rather on the opposite side, anyone from the audience? Yeah, thank you. This is happening. This is happening mainly because uh the the sound actually the liver and the gallbladder wall have the same density. And that means that the, the sound goes easier through the liver uh to the gallbladder wall and then turns back, that means because they have the same density, the picture will be clear that's why uh when we interpret an ultrasound scan, seeing images or a video, uh to define a, a thickened wall of the gallbladder, you cannot measure it. You shouldn't measure it in the opposite side of the liver. Only where the side of the liver is. When the, where the gallbladder is starting, the gallbladder wall starts in the liver. And this is the way to say that this uh gallbladder is thick in water cholecystitis. Yes. Yes. Um Again, the uh this uh this uh this slide shows the about the importance of sound propagation. And this is very important for us to understand surgeons and as doctors because you, you can realize what is happening if you have two different tissues come together and the, the sound goes through them. For example, if you have soft tissue and water, uh very close together, the intensity of uh reflection coefficient R is, is almost zero, that means uh there will not be any reflection of the sound. That means you will see very clearly the soft tissue in the water because they are almost similar. Uh almost the same applies with fat and muscle. If we are talking about bone and fat, that means if you have fat close to the bone, uh with the refraction 0.4 that means they don't have a similar, the those tissues are not similar, they have don't have the similar density. The sound that will be affected will be 50%. So almost half of the sound will be affected. So the image quality will not be good and almost uh and the uh and as you can understand, if you have gas or air close to soft tissue, you will not see anything. That's why some of the ultrasound scans. I do have reports saying that because of underlying uh bowel. So, so that you cannot visualize the appendix because of gas, uh underlying bowel gas or uh you cannot visualize the gallbladder easily or the common bile duct because there is bowel in front of it. That means if there is gas close to the tissue, you want to recognize ultra ultrasound scan, almost all the sound will be affected. So nothing will be shown in the screen. Um So this is not pathognomonic. Next slide, please. Uh The reflection is very important and you, you see a very nice sign here of the gallbladder with a stone. Uh When there is uh when the density of the tissue is uh for example, like a bone or a gallbladder, the the the sound will go will drop on, this will come back uh straight away. So there will be full reflection and you will see very white in the screen, uh less grade than the rest of the structures. But after this object below this object, you will see an acoustic sado what does it mean? It means that the sound is not transmitted is is good there reflects 500% and you cannot see anything behind this. OK. So you can see it clearly what an acoustic sado is in the right side of the screen, you can see the large gallstone and behind it, there is a Sado next slide, please. Yes, this is, this is uh a schematic picture how you can uh realize the, how you can understand the reflection. Uh also depends on the object. If the object has smooth surface, then it's more likely for the sound to go straight in a line uh way and come back. If the the structure where we're investigating is irregular, it has a regular surface, that means the sound will be reflected and scattered. So it will go in everywhere. So the image quality will not be good, but we'll call it diffuse reflection. Next slide, please. Um Attenuation is a process when the sound that will go out of the probe uh will lose in its intensity, that means you will lose the strength. Uh And this is directly proportional to the frequency. You remember when we had another uh type of teaching in ultrasound scan, we're saying high frequencies give better uh image quality. Uh And um and that means that because you, you send the sound with high frequency, it penetrates the tissue very easily and comes back without having any a lot of reflections. And that means it will give you a better quality. You can see that when you use the lining probe. And uh when you do, for example, a superficial scanning, when you want to see the muscle, the abdominal wall, uh or superficial uh tissues, um this is called uh and it's very important to understand that because uh you need to talk about the distance of the object you want to, to find out. Uh And if there is an automatic machine, ultrasound scan machine, this is sometimes is uh measured automatically. Um Sometimes uh if the machine is uh is manual, you need to play with the depth. So you can have the high resolution image. Otherwise you can use some object, you, you need to play with depth with uh uh with the resolution with the focus and all of those things. So you can have exactly what you want to say. Next slide, please. Um or how they must have generated, as we said, uh the, the crystals that uh they, they receive the sound, they, they have a transistor, they give the sound, then they receive it back. And all of those are uh uh made as a piezoelectric effect. And you can see there's a signal, how strong is the signal or how weak is the signal. There are a lot of parameters. For example, if you don't use a lot of gel, so the probe will be very close to the skin and will not be any um gap. Uh This will result in a not very good quality Uh again, it depends if there is gas inside the area you want to see because gas is not um uh it, it, the, the sound cannot go through the gas. E so you have a lot of reflections, then it depends on how, how deep is the tissue and what kind of probe you are using. So the next, the next slide we will talk about this next slide, please. Yes. Um This is how they must generate it. Uh You see the curvilinear probe that he is giving you here, it sends the sounds in a line airway. But uh the because they, the surface is curved, it gives the picture to more wide area. Let's see. The next one. Sometimes uh there, there are automatic system that can give you the correct depth. Uh But most of the times we need to adjust it yourself. Uh Let's move to another one because I want to see you something, show you something more important uh the way you use the probe. And if you see most of the probes, they have a, a small uh line in the middle uh showing where the middle point is. You need to also to play about with the this this area which is the the middle area, uh how you will focus on this and how deep is the structure. Uh You can imagine uh if you use a high frequency probe and uh uh uh the your ob the object is close to you. Uh It will give you a better image if it is far away, gives you less better image. It is, it's not only about the frequency, it's also about how many seconds it will, it will take for the, for the sound to turn back to the probe. Let's move to the next one. Uh This is very important about the artifacts in which um I in which cases, you will see some artifacts we said about uh G we said about um uh we have the acoustic out from bones, acoustic enhancement. Um uh reverberation is like uh um uh a case when you will see you, they must aa and you see it in some cases when you have uh you do any, any fast and lungs, we'll see it later on and some edges are doing, let's move to the next one. The most easy way to understand the, the image that you're getting for the ultrasound scan is to think about colors. Uh Someone you can, someone can say the 50 say of gray but uh in ultrasound kind of has 64 uh in the gray scale of uh uh of the ultrasound scan imaging uh determines how strong uh is the is the echo coming from the, from the object. And what we are talking about, for example, soft tissues uh can be gray towards the white if you see black, that means what, what is black in ultrasound? Now, you are on mute panel. Uh Again, I don't have any feed. Oh yeah. No, I'm waiting for, for answers. Come on guys. What is it? What is black in the ultrasound scan? So uh fluid is an ulcer fluid. Yes. Yeah, good. So anything that is uh it contains water, it can be black. If it is something more thick, you can understand it will be uh black gray gray. You will tell me about the gas, what's happening? What do we say about gas rem? Uh Remember uh ultrasound scan is not like an X ray in x-ray. I agree that blood is gas. What's happening in the ultrasound scan? Black means uh Hi, Mister G. Hi for it. Black means that you don't receive any um any, any ultrasound waves coming from the objects. So either you lost the uh the ultrasound waves or got distracted or got obscured like uh behind uh a gallbladder stone. So it means you are not receiving um any waves from this region. Very good. That means either this sound was absorbed fully what's happening in water in Leki, in the Le uh areas or uh the sound when there uh came back. But there is a uh there is a side of below. That means uh there is no signal from below this object because there's an object in front of you in front of the beam that obstructs the view very well. That means so tho those two things the gas. Can you see it with the ultrasound scan? Can you see if there is gas with the ultrasound is gone? They say no, no. Ok. We said it before uh a few slides before but the the gas versus the soft tissue, there is almost one that means there is 100% reflection of the uh of the, of the sound. That means you cannot see anything. That means if you start scanning an abdomen and it has gas below the abdominal wall, you will not be able to see anything inside the abdomen. And maybe this will uh increase your your clinical suspicion for a pneumoperitoneum. Ok. The same applies as I said to you before, if you have a small bowel loop in front of the appendix or any other organ, and there is a lot of gas in inside the bowel loop you cannot see below. That's why many times the uh the the quality of the images or the uh the final diagnosis uh on the report is not clear because they say there is bowel um gas obstructing the view. You will see it many times in the reports. Ok. So the next, the next one is about Doppler. Uh you will uh roughly Doppler imaging is it plays with the frequency of the sound wave and how quickly it moves to you or away from you. That's why you will see red. For example, it moves to uh towards you and gives, gives you away from you and gives you uh this, um for example, you have an arte a artery versus a vein. It depends on how the machine is set up. It will give you a red color for uh for the artery because it goes in a specific direction and a different blue color for the vein because it goes to different uh diff different uh way the fluid inside it. Um It's very useful the Doppler month for also for an emergency surgeon because you can do it uh during um uh let's say uh fast to recognize the aorta. So you can see if there is an uh um like an aortic aneurysm. Uh you can do it intraoperatively if you have some uh low perfusion bowel to see if there is a perfusion uh in the mesenteric vessels. You can do it, you can use it in many, many cases. Even to cannulate, you can use a Doppler to find out where is the uh the artery and where is the vein next slide, please. So the most important thing in ultrasound scan, after all of those things we did, we explained is how to use the right uh probe. And there are some questions that someone can, should make before using the probe. What application I'm using the ultrasound scan was in for what uh I'm using it for uh uh an ultrasound scan of the abdomen. I'm using it to do interventional technique am I using for something else? How deep are the structures are they in uh superficial? Like I want to see a superficial collection will be one or two centimeters below my probe. It will be 215 centimeters because I need to see it abdominally. How big or small is the footprint? Do I do I need, do I need to see few centimeters below my probe and a very narrow uh view or I need to see a wide area like a cavity. Uh Does it involve a procedure? Is it the interventional? That means II need to use a specific probe uh and use a depth. So I can insert a needle for example, or a cannula. Does it involve a cavity or not, for example, a collection? So this is very important. Let's see uh the next slide about the type of probes for you as surgeons. Uh You will deal mostly with linear and carvi linear. The linear probably will say afterwards, a high frequency one, you can use it for soft tissue musculoskeletal. Um And in general structures that are very superficial uh Carlier is uh uh low frequency one and we use it for fast, fast general abdominal liver gallbladder, bowel. Uh And there are some other type of probes like phase array and endo which is uh mainly for cardiac and then for S and uh cases. Um you can see uh this graphic which is showing exactly what we said high frequency means high resolution, low frequency uh means low resolution but higher penetration. That means with low frequency, you can see deeper and not a very good quality, not, not a very high resolution. Uh with uh high frequency you can see superficial tissues. So you cannot go very low because the sound is lost. But you can see high resolution. We'll see some clinical uh uh applications later on. So the linear probe uh is a high frequency 15 to 15 megahertz, high resolution gives a good view. Uh less than eight centimeters depth, more than eight, you will not be able to see much. And there is a rectangular field of view. You can under you can see if it uh you can see the the image in the right. Uh because it's, it's not curvilinear, it's not curved, it can show you exactly like a rectangular. So you cannot see a wider view. You cannot have, have a wider view. Next one is the carvi linear ultrasound scan probe which is a low frequency 2 to 5 megahertz. Um uh It gives a larger footprint. You can see it's uh like almost triangular, it's not uh rectangular. Uh It is good for abdominal pelvic ultrasound scan exams. It can be used also for cardiac and thoracic and it gives better lateral resolution. Next one please. So um another important thing in the probe that you need to know is this indicator, some of them they don't have an indicator. Some of them, they have uh something like a dot Some of them, they have a line uh or another type of mark. This indicator gives, gives us an idea of the um orientation of the probe. The worst thing that you can do is to have the probe in a different orient orientation. So you cannot recognize the structure, especially you will see it is very important during fast scan because you need to have a specific landmarks. And you can see the screen, for example, in the fast, you need to see the morrisons uh about the um the uh splenorenal space. If you put the probe in the wrong way upside down, then you cannot understand easily what's going on. Let's go to the next one. Yes, thank you. Uh These are the planes uh We play mainly in transverse plane. Sometimes we need to uh to go uh on uh uh coronal plane. It depends what organ we need to, to see. For example, if we do fast and you go to the right upper quadrant, uh you mainly play on the uh coronal plane. Uh If you go and say you want to see the bladder initially, you, you play the uh transverse plane, then the next thing we will discuss uh is how you manipulate the, the probes. All of those things will be shown easily in the a practical session, but it's better for you to know. Uh So we have the sliding, the tilting, the rotating and the rocking. Uh let's see some nice videos. So the next one please. So this is sliding up down and right and left. So you see you can play with the the probe uh when you have the chance uh by moving up down, you change completely the picture and you see uh structures that are lower or right or left tinting, you need to be very gentle with tilting in a sense that uh the the angle that you are changing close to the skin as you go uh deeper, it change a lot. So initially, you need to change only only few uh millimeters. And see this is very helpful. For example, if um you have uh uh uh you want to do an ultrasound scan of the abdomen and you want to see the liver and the gallbladder, sometimes the liver is very high. Uh and the gallbladder is very high on the liver and the liver cannot be seen easily uh when you are close to the ribs. So what do you see? You uh you identify where the gallbladder is uh roughly and then you do a lot of tilting. So you can avoid the ribs. You will see it in practice. The next one is rotating again. This is very useful for cannul, you can rotate and see the long axis and the short axis of a vessel. We'll see it again on the practical session next week. And walking is uh if you do some um if you focus more on the right or the left side without changing actually the image, so you can gain a little bit more uh resolution, lateral resolution. Next one, please. Compression is a very important uh let's say feature of the, of using the probe, we can identify the DVT, we can see appendicitis if it is not compressible and appendix, which is not compressible, uh uh can uh can show us that there is appendicitis plus the uh how uh why is the uh the wall of the, of the appendix? And what about artery versus vein? Can somebody tell me from the audience which one is compressible and which one is not compressible? You can see it on the screen now actually. OK. And the artery is not, in which case, the artery will be compressible in the a in the aneurysm actually will be uh so, so why the artery which will uh will not again, will not be compressible easily. It will not be fully, it will not be fully compressible? OK. All, all also the arteries are compressible but not fully. Exactly if you have hypovolemia. Very good. And in which case, a vein cannot be compressible, thrombosis, thrombosis. Very good for it. In what, in which, in in another case, um Yes, that means it will be high pressure inside the vein. Yes. What else? After aosis? Yes. When we have calcifications on the wall of the, of the vein. Yes, very good. Next one, please. Do you have any questions? Because I will start making some questions, Mister G. Uh Please. Um uh Can you elaborate more about the uh the Doppler and the uh colors which you receive uh red and blue? Uh What's the mechanism behind that? So, the, the mechanism, thank you for it for your question. The, the mechanism is, as I said before, yes. Uh You found it. Thank you. Uh So uh the, the computer that is used for the ultrasound scan, calculates uh the the movement of a wave when it comes towards towards us towards the probe. Or it goes away. For example, if identifies a flow that's coming towards the probe, it pay it uh colors it blue. If it, if this goes away from the probe, it goes is red and then, and then again, uh it depends on how quickly co quick is a flow inside the vessel. It make it more red or uh or or more obvious to the ultrasound scan. However, if you do an ultrasound scan, a Doppler yourself, you will see sometimes that inside the vein, you will see some red dots. What is the, why this happening? Why it's not totally blue inside the vein? Because the uh valves might reflect the blood flow a bit exa exactly. So in, in the, in the artery, the vein, the the flow is constant. Uh because it works like a pump from the heart. But if it is in the vein, because the flow is made because of stasis and valves opening, that means the flow at some point in the vein will, will mimic uh arterial one to the in the ultrasound scan. That means it will, it will, it will come back and forth. Ok. So that's why you, you need to know the anatomy when you do a Doppler, uh you need to use the compression and non compression. So you can identify the, the acting in the vein from also this feature and then play with a Doppler. Yeah. Thank you, Mister G. You're welcome. Fareed. Any other questions guys? Let's move to multiple church questions because uh I think they are interesting and will be more, more helpful to understand a few things. So I approaching uh the first one to the pole guys. So we have an obese patient. Yeah. Yeah. II will read the um actually the scenario. We have an obese patient very common nowadays uh who presents with um uh a painful swelling and erythema close to his. Um uh and you suspect maybe it's a abscess or collection or maybe it's an incarcerated and like a hernia. Of course, your clinical examine the patient first because this is the, this is the most important thing and you're not 100% sure and you decide to use the uh ultrasound scan which probe you will use line carina, both or none of them because you don't believe in ultrasound scanning, you will never perform an ultrasound scan. In this case. See, keep of course, the patient is clinically. Well, he's sitting in a bed, he's just a little bit of pain, uh hemodynamically stable, comfortable and you just finished your clinical examination and you have the option of ultrasound scan bedside. Of course, you have nex you are in A and a. So answers, please. Uh let's give them some time. But so far, well, I II don't create uh Tobias uh results. Um No, nobody has responded, none of them. I will not perform an ultrasound yet. Uh I was ready to answer that but I mean, I don't want to, I didn't want to, to change the results. Well, I II like those uh multiple questions because it makes you think and also you see um things that you can uh uh explain a little bit more and help the the audience understand. Uh For example, at the moment, I can see, let's see how many total responses we have seven total responses. No. Yeah, I think you have that. I OK. So at the moment I can see here that you, you say curvilinea uh which means can can anybody from the from the audience uh tell us who answered cave uh tell us about the the thoughts. Why? So it was in the car. Mhm You know. Mhm Anyone should be six of you like it to be irregular interface. So um uh they say likely because it's a irregular, not irregular I interface. And what is that? And because the arch of view is quite uh wider. OK. Um First of all, because it's an irregular area ii it's not a, a reason to choose a different type of uh of, of a probe unless this area is fully, let's say um curved like the car line near one. But in um for example, in, in the umbilical, in this area, especially if you have um uh an an area which is a little bit more edematous, uh usually a little bit flat or uh different way, you'll have a, a lump. So the main reason to choose a a probe will be the depth that you want to investigate and also the resolution that you want if you want high resolution or not. So, in this case, because you uh investigate uh soft tissue problem, that means it's below the belo because it's very close, you can feel it. Of course, it's an obese patient. But uh don't forget that in obese patients, the uh the fat is not helping. And then let's say the resolution because fat is not as great as the other soft tissues to uh to give high resolution images. Uh I would use a Lion air one. So the the right answer is a line one. If you remember we said about eight centimeters depth I cannot believe that uh in his case, uh the umbilicus in the abdominal wall, the fat above the abdominal wall and the blood will be more than eight centimeters. Ok. So, II, ideally, you should use the linea. Both is also a good answer because you can change between line and it depends on your findings at that moment and none of them I will not perform S scan. Ok. Probably will have a, a belie a nonbeliever. Uh Someone who want to do probably ct scan or send the patient home without any scanning uh uh car. OK. Can be helpful. But I the idea alone is linea. So second um multiple choice question, a patient following me, laparotomy. Uh second day posts small bowel resection and anastomosis, complain of abdominal distension and pain. So what do we think about this patient? Second day post uh small bowel resection or thrombosis emergency laparotomy. What, what is the most common cause of abdominal dissection and pain guys? Yes, I have an eye list as a question. Yes. Cause of p eyes. So this is the suspicion. Yes, indeed. After clinical examination, abdomen, soft, distend, panic to percussion. No bowel sounds you decide to perform oro can like for small bowel, peral or intraabdominal fluid which probe you will use all of your car. Perfect. Very good. Oh, some are none of the OK. Probably it's the same one. So uh II agree also with four, none of them as uh you will not perform ultrasound scan. OK. Sometimes it cannot be useful to use an ultrasound scan. But uh it is proven that ultrasound scan is more sensitive uh from uh comparing to your stethoscope for recognizing peristalsis of the small bowel. That means that if you put an ultrasound scan probe in every patient that you, you, you see postoperatively and you can see peristalsis. But if you put the stethoscope to auscultate, uh maybe you will need to wait many, many seconds. So probably you will not hear anything. Uh So yes, is the right answer. Let's move to the next one on his next slide. Yeah. Uh 80 year old patient post fall. So we have a mechanism of injury of your skin brought by ambulance and you decide to uh do primary survey ABCD. After B you perform a fast scan which probe you will use patient is stable at the moment. Uh Just brought by a knee, you are doing primary survey ABCD, you are finishing the B and then before C while uh while your colleagues put some can as you perform a fast scan which uh probe you will use for the fast scan or maybe you will not do any. OK. Again, we have more Carline, I agree with that because uh a fast scan traditionally is done by, with a Carline probe. So nowadays, if you go to to A&E sometimes they have uh machines that most of the times in A&E because they are using research, they have a car one set up but sometimes you, they have uh uh a line near one. Please be careful. Don't put the line near one. when you want to do a fast scan in the abdomen. OK. Fast is always investigating the structure that are deep. So carvi line, a patient of BMI of 50 is difficult to cannulate. And after several fatal attempts, you decide to perform on cannulation, which probe you will use. So which probe you will use for cannulation? Not only BMI of 50 uh any kind of BMI. OK. I hope someone will answer the fourth question or the fourth. Uh It choose the fourth answer. None of them. I will call somebody, you call the anesthetist. Yeah. Uh but yeah, it is the L1. Uh why? Because you said that this is uh uh uh a pro we use for super structure. And also again, you can play with uh uh pushing or uh finding the compression or not. OK. Good. I think we uh we finish. Let's summarize uh take home messages from this presentation and we will go uh very quickly to the clinical scenarios. Uh take home messages. Ultrasound scan is sound as soon as you realize this um then everything comes easily. Uh If you understand the ultrasound scan principles, you, you need to know them before doing uh point of care ultrasound scan. Otherwise, uh you will lose a lot of time by adjusting uh the probes and uh the uh the measurements on the machine, choose the right probe. Uh Ask those questions. We said before uh techniques or manipulations are very important. We see it also in the practical session. Um You need to accept that you will spend a lot of time when you do that. So you need to sit down with the patient, inform the patient, take a verbal consent. Have someone with you, please do not uh take videos in uh of the procedure or the anything else without informing the patient and take a verbal consent. Uh perform as many as you can if you can and you have the concern of the patients. You can uh scan every patient you see in A&E or in the world. So uh to use it, you have to believe in its value. If you don't believe the ultrasound scan uh is a tool as a stethoscope, which will become as a stethoscope in the next few years, in my opinion, in surgery and medicine. Uh then uh you will not use it properly. Let's move to the clinic scenario. So uh p please load the the second presentation which should be the scenarios in a clinical setting for the emergency surgeon. So next slide please um ultrasound scan and emergency surgery as you know, very well. We use it in trauma surgery fast and a fast, a fast uh refers to check the test for pneumothorax, nontrauma surgery. You can do abdominal viel s scan, soft tissue, vascular and interventional. Next slide please. Um In UK, it's performed by ultrasonographist and radiologist. Uh However, in, in other countries of Europe um or um in the world they use, they've this ultrasound scan is used by uh practitioners like um for example, surgeons uh they do interventional techniques, paramedics, um and other healthcare professionals point of care, ultrasound scan is done mainly in in emergency setting by the physicians that are not very popular surgical community. Unfortunately, should be. Uh We use it in our daily practice as you know who is doing what wrong with me. Usually I'm using this uh machine. Um it is a little bit challenging from the medical legal view and the excedrin for m for mild colleagues. However, uh you need to protect yourself by document everything you're doing. You need to write down point of care, ultrasound scan rather than ultrasound scan, point of care. Ultrasound scan refers to something bedside uh as a as an adjunct to your clinical examination. So, uh my recommendation is if you want to perform that and I have many of the junior doctors performing like shots uh like more uh fare um uh uh while you perform this ultrasound scan, guys, write down point of care ultrasound before that you need to say verbal consent was taken from the patient. Uh And you write down point of care, ultrasound scan done uh bedside by this surgeon. Uh and um my clinical don't write as a report, you need to write down that the definitive diagnosis includes, for example, collection where strangulated hernia. Uh the ultrasound scan showed um that there is a little bit piece of fat or omentum uh in the defect of the hernia. And that means that possibly is an incarcerated on the light of hernia, for example. So don't write it as a full report, write down what you saw in the ultrasound scan and how this can help you with the final diagnosis. So you need to write something a little bit clever rather than writing like an ultrasound scan. Uh a specialist who is writing the reports and um uh impression. Uh the the other way you can do it is when you write all of those findings, you and you are not 100% sure. You say a formal ultrasound scan is recommended and you just asked for a formal ultrasound scan. If your diagnosis is almost sure, then uh that's fine. You write down your your clinical diagnosis, not as a report case scenario. Number one, let's move. These are real and I responded to myself mainly things. So, so one Tuesday morning, um there was a cirrhotic obese 64 year old patient with ascites and medics. Uh the the medics uh tried many times to do a centesis of uh acidic fluid in the right abdomen. Um They managed to take a sample. But the patient became septic after and the patient was trust with the ICU. So I did the ward round. I was doing the word draw the IUD next slide please. So they said to me, we have these patients uh on the bed quite obese. Uh I did a ward round about nine o'clock on Wednesday. Um They requested the surgical opinion for query perforation patient at that moment was in sep was septic. Uh with ongoing respiratory failure, you can see the stent and abdomen like this. Um a lot of ascites that was obvious we knew that he this patient had ascitis and uh obviously high into abdominal pressure. And uh it asked for a cytic drainage catheter under the ir next slide, please. Uh So when we do the, so it was 830 not nine. OK. Uh So when we did the uh the ward round there, we, we saw the patient examined the patient first of course, uh still waiting confirmation for my heart. So the the patient was becoming unwell because the hands of those my pressure compromised the airway, uh the the actually the breathing and then the airway. So the patient was not in a good uh good shape. Uh Next slide please, what you will do one in this case, you are 830 after the patient is septic become uh well. Uh There is no, there are no news from intervention ology regarding uh um an eye or drainage. Um And you have option request to see the abdomen pelvis, see what you want to see. You tell me what you want to see. Uh ent fores uh exploratory laparotomy, bedside, ultrasound scan and position of a drain request, generic chest X ray. Uh Wait for inter to position to drain all conservative man with an and respiratory support. It will become uh now those questions are a little bit more advance, but it's good uh for you to squeeze your brain. So, let's see. Um Do you want to like make a small recap? Like we have this patient? So because I cannot go back and they cannot read the Yeah. So the uh we have a patient who uh is obese with a distended abdomen full of ascites. And um the uh the medics attempted several times to drain the acidic fluid. They, they failed. And uh after the third or fourth attempt, the patient became septic and they, they had a lot of consent. So they transferred the patient care and this was happening, this happened on Tuesday, on Wednesday morning. They asked a surgical opinion because they thought that there is a bowel perforation because probably they thought that the medics uh put the needle in the bowel and there is uh now ascitis which is um causing an intraabdominal infection, peritonitis. And they asked surgical opinion. The patient was deteriorating. Uh in the meantime, uh since yesterday, they've been chasing the interventionalist for a uh for an acidic drainage and still uh despite patient becoming unwell and um not getting uh better from the respiratory main point of view and sepsis point of view. Uh Still that we're waiting for uh I RN desperately they asked for a physical opinion. So we have four responses so far. OK. And they've had no imaging, no imaging. No, no, no imaging. No, the ultrasound. Uh Yeah. Good question. Did the medics try the paracentesis uh blindly or with ultrasound uh blindly? They don't use ultrasound scan most of the times. It's, it's a paracentesis. The classic parasit, which is uh it's the number two when we say this, we attend first. So this is just you uh you use your finger, you, you see the area that is dull. Uh you go mainly in the left, lower quadrant or right or right, lower quadrant uh where most of the fluid is and you just insert an indole, you aspirate. This is how they tried three times. And that's why the medics asked for an IR again because they didn't want so the I ID doctors because they didn't want to reattend and it should be the of the uh so have you? No, I'm not. Uh Yeah, you don't know if there's a lot of what are we doing? Yeah. So uh sad to saying that uh if we don't know if we expect a perfect and we don't know what's going on. Maybe we should do a CT and maybe your laparotomy if that's a perfect. Yeah. Yeah. Very good. Uh Very good point. Uh So, uh you want to do a CT scan abdomen pelvis in a patient with distended abdomen with ascitis. Let's say that they indeed they put a needle inside the bowel what you will see in the CT scan before and after the needle bares, let's say, let's say you had a CT scan three days ago showing uh full of ascites, the abdomen, full of fluid. And then you uh they do the do a paracentesis and you think that there is bowel condoms inside the uh the ba the abdomen. Um And you do another CT scan. What did the CT scan will show? What will the will the comes from different, different from the previous one? It will show a free abdominal wall uh when it, it may be a anyway from the drain. I think I would, if it's or a spiritual perspective, I would put a drain in the bedside just to, to reduce the intraabdominal pressure. Then for a CT after, yeah. So uh some people say that uh because he's um not very stable, uh they would put a drain in, quickly reduce the intraabdominal pressure and then maybe take to see when he Yeah, but as like a prevent ultrasound in ultrasound scan and position the drain. Yes, just to relieve it because you said he has high intra abdominal pressure. Uh le let's move to the next slide I think. Uh yeah, let's see what, what happened. So I decided to do a not a bedside ultrasound scan of the abdomen. Uh I saw this uh so you can see the black means fluid. Uh the white is the tip of the needle. OK? Because it's metal, that means it will be shown more white. Uh the sound is going and come come back to the high density in the probe. So you can see it very white. Uh And also you can see uh the bowel bowel loops which are like uh white with gray inside. You can see them like lumen. All right. The fact that the uh the fluid inside the abdomen looks very dark black means that it's, it's a good sign if it was grayish, that means maybe there are bowel contents. So I inserted um uh with the sate technique, a catheter uh under vision. Uh that means II use the guide wire and uh like we do in central lines under local anesthetic and uh 5, 500 MLS of clear acidic fluid was initially drained. Ok. Next, next slide. So point of care, ultrasound scan, uh it can be fast, avoid delays if especially if there is a lifethreatening uh situation. Uh it's safe because it's under vision. Of course, you need to know how to do it. Huh? Uh It can be bedside procedure. That means it can be done at any time in any case, uh close to the patient. And um uh of course, it's safe. Do you have any questions for this case? It is a little bit tricky. Uh especially from the medical legal view. Of course, trainees, you should never do that. It should be done by a specialist. Uh Of course, because you're not covered and also you need to be uh very, very careful if you do it, a specialist, what you will document and of course, what kind of qualifications you have to prove later, if something will go wrong. Uh Any anything anyone uh that can uh can say to you, you shouldn't do it. Uh Mister G One question from just is um did the patient ended up, did we confirm or exclude the after? So we drained. We very, very good question how you will exclude the, the uh the pe by doing this? Well, you can have a look at the content that's coming out of the drain. If there's any infection, you see, you see it's, you, you see it's yellowish yellow. That, that sounds like it clear to me. Um um Obviously you can in for a CT and it's difficult because you, no, no. Uh le let's, let's focus on the, on the drainage uh the drain, the, the fluid that you will drain, how you can uh understand if uh this corresponds to a peritonitis or not. So you said color OK. Color me means someone, if someone, uh, if someone cannot see very well or it can, it doesn't know how acidic, uh, fluid looks like if, if there is any, uh, is, uh, any, what air, air, any gas. No. Uh, I mean, how, how you, I mean, you take, uh, uh, you put the drain in and it comes out with, uh, fluid comes out from the drain, you cannot see any gas. Of course, if there is so much gas that you, when you put the drain, you will feel like uh w when we have pneumoperitoneum uh in laparoscopy, that's fine. Yes, but obviously it will not be. So it's so easy to understand. Can, can we send you the other thing? Can we send or somebody can? Yeah. Uh You need to send the sample to see what in this. Um Do you remember, do you remember in ATL S what they were saying about Perinia lavage? Yeah. Don't remember. I think is it albumin? No albumin. It will be depends on what kind of ascites it will be. But uh uh you se you send for uh leukocytes, leucocytes. Uh Yeah, this indicates infection. All right. And of course, if you send, if you send for uh for uh biochemistry bile because mainly, but you can uh the most common organ that you can damage with a needle if you put in the abdomen is a small bowel. Um If you send the biochemistry with bile and it's the serum bile. That means uh it's normal. If you see high bilirubin, then may, maybe there is a perforation case scenario too. Yeah. Where was uh in case of leucocytes? This lady's office is, and she's had for a while. She might also have SPP in which case she will have leucocytes without a problem. It could be. But I mean, you correlate all of those findings together. You, you're not relying on low leukocyte, you're relying on the color, you're relying on how the patient is doing. After removing uh 500 amounts of fluid, uh you check the respiratory um uh status many things and you make a decision. Yeah, of course. One second. G because the screen got disconnected. Give me one second. All right. But with the CT scan, abdomen and pelvis, you don't see anything a a small perforation or small traumas in the abdomen from road traffic accidents that you may have AAA small perforation of the small bowel like a bucket handle injury with a small uh serosal tear or uh uh wall of the bowel there. Uh You cannot see with the CT scan, you cannot see the hole unless there is a massive, ok. So don't rely on CT scans in those days. So case scenario number two, let's move to 87 year old female, 80 acute pain, a lot of vomiting, loss of appetite, feeling unwell, uh past medical history, hypertension, liver cirrhosis, hypothyroidism osteoarthritis, no previous suppress regarding urinary infection. Though on uh, on examination, abdomen, soft, mild generalized tenderness presence presence, uh bowel sounds um, BP, borderline high uh tachycardic uh at 7.3 temperature inr 2.1 high white blood cells and crp urine, deep leukocytes plus one plus protein, one plus ni no nitrates. Next slide, please. What do you do? So ct scan, abdomen, pelvis, abdominal X ray and excess x-ray pa scan uh conservative management of antibiotics, analgesia, palliative care, just analgesia because she's 87. No need for surgery. Ask uh gastroenterologist to see the patient referred to medics. In other words, you. So we have a seven year old patient with abdominal pain and vomiting of 12 hours loss of abdomin feeling well, who has the soft, mildly extended and, and bowel sounds low BP, tachycardic. Uh not exactly febrile uh temperature 37.3 like maybe a little bit inr 2.1 white cells are 16.7 crp 71. So increased inflammatory markers and uh also urine deposit for leukocytes and protein but not nitrates. So first question would be, what do you, what do you suspect? And the second, what would you do to find out? And also, let's see the history again. Uh hypertension cirrhosis, hypothyroidism, arthritis, uh recurrent uti S oh gastritis also. Yeah. Yeah. Also, I don't know the mechanism II might add. Um like, well, I mean, there there is no there is no, there is no mechanical uh fall or any, any injury. Uh So I keep on some abdominal pain at 70 year old, vomiting, nausea, loss of appetite. So the, the question is not, uh what is the first thing you will do? Not? What is the best test or whatever? What is the, what is the next step from your side? I mean, someone can say, ok, the next step is to ask for a medic. Uh Someone will say, OK, I will not do anything because it's palliative. Uh uh Someone says, admit with antibiotics and all. Yeah. Let's see the responses. No, three responses so far. F scan. OK. Let's uh let's move to the next one to see what happened. Thanks. Bye. OK. CT scan. All right. Uh I'm surprised you didn't say CT scan. Uh because uh you do all, all the time. You do this. You have CT scans in patients. Now you don't ask. So CT scan, abdominal pelvis reported free abdominal fluid in four quadrants. No free air thickened wall, small bowel. Uh an S MA and S ma patent three intraabdominal fluid fluid in four quadrants. OK. No, for gas. Let's move to the next one. What is the next step? Now guys, one to put the pole. So we found a lot of free fluid in the CT scan patient is tachycardic uh BP, 95 systolic temperature, 37.4. Um And what high white blood cells were 16.7 CRP 71 and obviously was she was stable to go for act scan of. Is it the question, the question that just fit question is we, we came this patient hypertensive tachycardic uh this symptoms, but we did initially ct scan and found there is thickened bowel uh four quadrant, uh sorry, um fluid in all four quadrants, uh SMS and be patent. And let me go back and see if there's anything. And also, uh yeah. So the, the question is based on the addition of this information, what would you do next? Patient is 87? With a significant past medical history. Yeah. Yeah. Just for context. It is patient with c cirrhotic hypothyroidism with arthritis. I mean, the, the most important thing is cirrhosis, I would say and hyperthyroid with inr of 2.1 I Yeah. So there is um 55% laparotomy, uh 25% laparoscopy. 50% abnormal guidance. Nobody uh per nobody antibiotics, analgesia, nobody palliative care, nobody. The gastroenterologist. Well, to be fair, cons uh antibiotics and SIA will be starting but not conservative management. II would say no. The, the question here is uh it is about conservative management. Yeah. Not deserve first. Yeah. Yeah. Might as well. Ok. Let's, let's move. Uh The next one. Let's see what happened. So it's not because uh we are talking about ultrasound scan but uh this is what I did. I did the point of care, ultrasound scan uh bedside in II remember this case, this lady was an old lady in bed two in recess. Uh and um uh I was with one of the ST four registrars. It was about 10 o'clock in the evening. So we need to make a decision on what's going on. So I did the percentage on the ultrasound guided. Let's see what happened next. This is what I found. Can you see the fleet? What do you think? Yeah, I will say looks acidic. Yeah. So finding this and of course, sending to the lab which came back with no uh no uh leukocytes or any other things that maybe indicate uh peritonitis. I decided to continue with conservative antibiotics. Ask for a gastroin later on as a second opinion and the patient start improving the next day. They start after four days. Ok. So the patient aside, basically. Exactly. So you can imagine what will happen if you did if you were doing a diagnostic laparoscopy or an extra lateral laparotomy to an 87 year old acetic with inr of two going on because the ct scan showed uh fluid inside the abdomen and the patient had high white blood cells and a sign of sepsis. All right, probably you will kill the patient. So point of care, ultrasound can save under vision technique again, if you know how to do it. Uh it can save a patient from a laparotomy laparoscopy it's a little bit uh erone what the right here can save patient from, from laparotomy, laparoscopy. But in that case, laparoscopy or laparotomy would kill the patient. Uh I want to be clear with that. Uh and uh may, may facilitate early diagnosis. And again, it's a bedside procedure like we said before. And uh and that's it. Uh So it is a useful skill for ultra, for, for the emerg surgeon. The ultrasound scan. Again, I will say it first to use it. You have to believe it. If you don't believe in ultrasound scan, then don't use it and you will never use it in your life. Uh And I said again, uh I was not a believer but I became a believer after doing a proper uh course. Uh it is an adjunct to the surgical practice. Uh I feel in my everyday practice that is like a stethoscope. Um I at some point so far more and uh some uh some other uh surgical registrars and we're using the oro scan. I have one in my office actually in a small bag that you can use. So you can uh have it in uh on you. Uh when you uh examine patients, no operation, of course, no radiation cheap, easy to, to use, no waiting list, uh no radiation, no problems. Uh You can use this many times as you want. It's a dynamic scan. You, you see the patient, you check again and again, you see with your own eyes, you don't have like a static image that you need to make a decision. It's portable, which is very, very, very useful and you can use it bedside, you can use it in the words, you can use the name, you can use it in theaters while you operate so very, very useful. Uh And as I said, it can be used without any limitation before surgery, after surgery, during surgery. Whatever. Uh, of course, you need to know some tips and tricks and, uh, you need to know in which cases you will use ultrasound scan, uh, to help with your diagnosis. Ok. It's not used for, it's not useful for all the pathologist of the world and in, uh, uh, in surgery. But in some cases it can be very, very useful. That's it. Uh, I think, uh, let's move to the next question. This is what I see every morning when I wake up and my cappuccino. So it's not because I'm obsessed with gallbladder as well. Uh, because I'm obsessed with ultrasound scan. Any questions, guys before finishing. That's it for today. Uh, ne, uh, next, uh, um, the next session will be next week, face to face and we'll do some nice practical exercises and use, uh, the ultrasound scan of her. Uh, had a very interesting question. Uh, could we also use it in clinics, you know, like hernias? Oh, yeah. Oh, yes. Oh, yes. The only problem is who, who was the um you, it was you 11 of the, one of the s OK. Uh Yeah, so if it is a very good point and I many times in my clinic I was wishing to have uh an ultrasound next to me, uh or a portable one. but the only problem with the, with, with clinic is that you have limited time, time and uh ultrasound scan, unfortunately, uh you need to accept that you need to spend time to make it clear. Of course, if it is something very quick, for example, an umbilical hernia, I mean, if it is something quick that will take you a few seconds with the ultrasound scan, probably you don't need the ultrasound scan. You will uh you will find it with a uh with a clinical examination, it will be very obvious. Uh But um yeah, it will be useful as soon as you know, and you use it very quickly and you have time in clinic if you have a slot of 15 minutes per patient. Uh and to be extended to 20 or 25. In some cases, if it is uh difficult to understand the the history or the patient is put, you saw you uh using ultrasound scan last uh 1015 minutes more, which is not sustainable, but uh in an ideal world when you have time and you do a proper uh good quality outpatient clinic when you become consultant product. Yes, please use ultrasound scanner will make a difference. Of course. Again, you need to be very careful about documenting and for medical legal purposes. Yeah. And I also ii think in a word or a context, um just, you know, to do an ultrasound and then if the patient is anyway, going to have a formal ultrasound to do a bone, so you can compare what's happening, it is happening already. Uh You've seen many times that the A&E doctors uh saying uh uh an ultrasound scan was performed in A&E and we found gallstones. All right. And it's good for sometimes in triage if you have a patient with the right upper quadrant, uh which you can do an ultrasound stunt straight away and identify Goldston. There is no, you know, exactly where the patient would go next. You can easily even decide patient mainly without a surgical opinion and send the patient for to hot clinic. Uh Tomorrow, I'll give the surgeon to see for an a case, I think like a biliary colic. Uh And of course, if you can identify uh cholecyst, it's even better because you, you just ask for a surgeon to admit straight away. But this again is an ideal world that uh when the uh emergency physicians are very good and competent to do ultrasound scan. However, emergency physicians are the few of the uh