Transcript for:
Rotem and TEG Overview Lecture

foreign [Music] [Music] and today we're going to talk about all things Rotom and tag as it pertains to this question from 2022 in the first setting number four and the question there is draw and label a graph the normal basic viscoelastic tester clotting function what information about the physiology of clotting is depicted in this graph how will the graph be altered by hyper fibrinolysis yeah wow that's a that's a mouthful that's a big question yeah and look this was a request from a patreon not um specifically or actually what specifically a couple of weeks ago but uh more so in terms of they wanted me to go through a question that's been asked over the last couple of years with a very low pass right so this one here had a 25 uh pass rate and what I normally do Lars I'll normally go through the exams report um and you can go through it and the ones that are highlighted in green are the ones that I think are really important and key to add in the answer here okay is there any um correlation between lowest scoring uh saqs and then repetitions I do remember definitely for the part two I remember they repeat they repeated one of the very low scoring oxygen delivery ones into the um you know into the next exam which was directly on our exam is any correlation there look I haven't done any direct you know statistics to actually prove that but I think there isn't you know uh an inkling that if there is a question that with a very very low pass rate they certainly will ask it again especially if they think it's fair now that that is a caveat because there have been questions in the past that have been asked which I think um either poorly worded or perhaps asking you know for a topic that um might not be relevant I.E I think that was a question on Gentamicin many many years back which hasn't been asked since then and those questions there haven't been repeated since then so there is a caveat to it um but I think also that uh you know this question you know for me I must say to you that I did not think they would ever ask a question on tag or Rotom I'm going to be honest with you yeah bio disorder is very part two stuff that's where we were tested on it I agree and yeah but but at the same time I think that you you know we have to evolve we have to understand that I think um Tech and Rotom are now almost a part of um and you know anesthesia practice especially in Metropolitan obstetric trauma hospitals so I think it's good to know some knowledge and the key today is that I know it's complex but I'm going to try to simplify um as much as possible okay and and that is the really whole um aim of today is just to really create a very simple platform for you guys to go back and understand and be able to reproduce easily I acknowledge that it's very very complex and I think Lara and I you know we use it and I'm gonna be honest with you even some of the numbers I still don't understand numbers yeah like I don't I don't use it often enough you know it's it's not like I'm a one of the registrars on call doing obstetrics day after day or in a trauma Hospital anymore so I'm just not looking at it every day I have to I'm going to cheat sheet that I've stored away in my notes and I look at that every time I ever you need to use it and I mean that's just that's just how it's going to be now um yeah be the same yeah this question uh so what are they saying so that it consists of three domains draw a graph of viscoelastic test of plotting function link the graph to the physiology and describe the effect of hyper fibrinolysis so that's really complex there's not an easy question to do if you haven't practiced it um the answer which is called poorly in one area could be compensated for by better answers in other areas to pass the first section it was necessary to produce a basic outline of a tag or Rotom so either one along with some clearly labeled common indices such as R time CT or pulling time Alpha angle Max amplitude ma or mcf Etc credit was a water including normal values the second part of the answer need to link the various components of coagulation process with specific phases of the graph such as the contribution of platelets to Ma and mcf and the final part of the question required either graphical depiction or a written description of the characteristic changes seen in hyper fibrinolysis credit was given for an explanation of the pathophysiology and the role of aptum but was not required to pass interesting oh so there's more of it so no marks were awarded for describing the process by which the graph is created or the evidence for its use in specific specific clinical scenarios as this was not asked for simply listing common Integra and parameters or pathologies without linking these to the graph also attracting no marks so common errors and a whole bunch of common errors here imprecise or incorrect labeling of the graph lack of X or Y axes incorrect units or numbers directionless comments for example Alpha angle is affected by fibrillion confusing hyper fibrinolysis with hypo hypopropinogenemia lack of I'm glad I'm glad I've got you here because I would have struggled to say that word I think I struggle with it I lack of understanding regarding the contribution of specific components of coagulation to various phases of the graph and not realizing that thrombolysis is a normal part of the coagulation process yeah wow so look I think this was one of the key ideas here from this question is that you actually need to know what the shape is and I think that I've seen so many variations of what a normal shape of a tag or rotation should be you know yeah I mean and like can you describe for the ones in the radio what I've got here on the screen I love this so standard did you come up with this did you well I mean I I had to associate some of the uh shapes with uh you know the these um these images here but yes I did I did sort of find uh all these shapes there this is a great mnemonic I gotta say so the first one is a wine glass and you know you can just see the normal you know this would be the normal pattern really so normal you're obviously not just a wine glass it's a it's a I heard there's a different this is a brandy tumbler a brand of Brandy glass yeah because there's a difference here if you see the other ones there are there's a different type of wine glass that's there so this has to be like a brandy glass I think I've actually got one of these that I bought from an OP shop um you know it's got the a nice like like it's a fat base and a slow angle to a smaller you know circle like the upper lip and then you've got the egg shape everyone knows what that looks like got a small sausage so what would that be like a was it a small wiener or a small chorizo and then yeah and Dale sausage yep and then a maple leaf if you imagine a maple leaf has a much steeper angle more triangular shape than say the wine glass which is a softer angle to the opening of the glass yeah correct and and so look I want to sort of ask someone um you know one of our listeners to sort of uh give us their their thoughts on if they were to draw this graph here on this exam which one would they draw so live you know out of the ones that are there which one do you think you would draw for um this question here or a normal graph yeah for a normal what what we consider a normal uh table Rosen um I would probably either the leaf or the wine glass that depends how fat the leaf is yeah yeah and you're certainly not wrong I mean I I think um that is one of the key ideas here is that with the with the leaf what will be the big difference between the leaf and the um Brandy tumbler was really fat then it would probably be hyper coagulable um and then the leaf if it went um quite narrow quite quickly that would be hyper fiberinolysis yeah correct so essentially I think we can agree that those are sort of the the two shapes that we often see represented as what's considered normal in fact the egg in the sausage the cocktail sausage I've seen as well represented as normal um but certainly it's how you want to describe the fibrinolysis that occurs at the end and it I guess it also has to do with the timing you have on the x-axis okay and you know I think the other sort of confusing thing that uh you need to know about is for Rodman Texas what are the numbers that you need to know and I'm sure you guys have seen all these numbers and we don't need to go through it because and I'll go through it in fact each one specifically but when you see it represented in this format it can get really confusing and really overwhelming now um Laura I think if you can go through this graph this this is probably one of the articles that I think a lot of people reference uh you know their answer from and I think a lot of um sources from the uh from the internet actually use this graph here from this article in cacdp to um really reference in terms of what they talk about roadman and Tig Yes sounds good and look I just felt like a glass of water and here is my op shop um what do you call it a brandy tumbler so oh yeah yeah let's have a look hold on let's have a look I want to see it I think that's the one uh anyway so can you see anyway that's fine let's go back to yeah oh yeah yeah it's very nice but yeah so uh share the screen again if you would there stand and um yes this is great I mean I think everyone's heard of the BJ education it's now called the bja education series and this was Warwick in 2013 and still very relevant so this is a bigger one typical tag and rodent tracings um and pretty much what we're showing here is the reaction time so R being the time by which you actually start a clock forming and then the next thing that you mostly look at is the alpha angle on this graph and really that shows the rate of plot formation you get this maximum amplitude which you know makes sense that it's the maximum amount of platform and then you get this like decrement which is you know measured at cl30 and cl 60 or ly30 and ly 16 it's rotor so yeah I mean interestingly you've got and what shape what shape would you say that is what shape I mean that looked like the M tumbler yeah it looks like the Tumblr Brandy tumble I agree so you know that that's one of the things I want to point out is that uh you know in that previous graph sorry diagrams that you see you can see that one that this one here this one's a maple leaf and this one here looks like an egg and again these are representation of I think um off the graph I don't and I think what what happens is that they're trying to describe all the numbers and what happens with each of those um parameters but by doing that I think a lot of us take that as this is representation of normal and I think that's one of the key points here today is that um when you see a diagram that has all these parameters labeled just be aware that it may not be the accurate representation of what's normal I think it's fair to say that this would be considered normal and in fact this would be a real life example I think this is something that you and I would see every day like not every day but when we do Obstetrics and run uh Rotom um this is the kind of shape that we would see a very elongated Brandy tumbler absolutely okay I just wanted to add that um so I I grew up in a very Buddhist household and um so you know in like the um the graph of the maple leaf it's got a bit of an angle to it I just wanted to show you what this really is like to me and the Bodhi Leaf so this is the leaf of the tree yes that the Buddha got you know or principa became enlightened and this is a very popular kind of symbol in Buddhist culture and because you've got this like tail at the end of it so if you imagine like that's that's the you know abnormal sign of hyperbinolysis right so to me that was a Bodhi Tree Leaf yeah or is it how would it be represented what was that sorry I was in just had one of the leaf um in like with the like with the Statue or they were sitting on the leaf or it was in many different forms so yeah I wouldn't worry about that but um yeah like say this picture here you know it's it's just a symbol of Enlightenment in British culture yeah so there's there's a bit of culture but yeah there you go okay so Enlightenment is essentially hypofibrinolysis gotcha pretty much yeah all right so um and so look I think that one of the key ideas here is that when we think about you know these Visto elastic um graphs there are two types there are tags and there are rotoms okay and and a lot you want to go through um the the difference between the two well you know I mean what why don't you go through though that's that's fine well well yeah so so it's essentially the way that uh it performs the uh the test and and essentially a tag or thrombo elastograph rotates the cup with the pin in the middle and then a Rotom rotates the pin okay with the cup stationary now the thing is why you see all these different numbers is because a Rotom has so many more um additions to it so it's got things like xtem intem apptam hip temp now I don't want to go too much into detail for each one because um I think the main aim today is how we're going to pass this question here I think if you want to do well like you won that four out of five that's when you start thinking about what does each one of those mean and and look it's not that difficult so xtem is looking at the extrinsic pathway it's got tissue factor to essentially start the coagulation Cascade when we're talking about intent it's the intrinsic pathway so it's got phospholipid and iRig acid to activate the intrinsic pathway eptim has a protein in to inhibit fibrinolysis otherwise it's essentially um extemp heptam heptam looks at the Heparin effect so it's got heparinas to um to basically antagonize the Heparin otherwise essentially like in tem and then FIB temp has a platelet inactivator so what it does is it takes away the plate load effect and I'll explain to you later why that's important because when we go through the concepts of each one in terms of how that um how the graph is actually developed one of the key ideas there is that platelets and fibrinogen have a very close role together and sometimes it can be very difficult to tell which one is is it is it fibrinogen or is it platelets and that's where fit 10 helps you out on that you stand so does this mean that Rotom is far more specific for different situations and in a sense is it better than tag it it depends on how you interpret it like the the manufacturers of tech would argue because they've got other um parameters that I think can give you that same information that rotten has so it really has to do with how you interpret the information so in other words that Rotom has like a um coagulation index which it calculates using all the parameters that are there which Rotom doesn't have so so each one has a different um uh I guess advantages and disadvantages but in saying that you would you would argue right that because you've got all those xtem intentimes it gives you more information and I think that what I'm seeing personally is that uh raw term is definitely becoming a lot more ubiquitous around hospitals than tags texts I think when I was coming through was probably the predominant one but yeah now it's um now it's rotten okay yeah and um and so look this is one of the key ideas I wanted to talk to you about I know that there are many many ways that we can describe it um but I've summarized it and and this is my this is my own way that I think about this and I hope it's nice and simple and for you to you know um replicate and use and you can even adapt it however you want okay but the way that I think about it is how you start coagulation what is the speed of correlation what is the strength of coagulation and what is the stability of the clot so really four s's start Speed strength stability how does that sound a lot yeah I think that's a really good simple way to get it through love a good mnemonic and so yeah and so by understanding you know what starts coagulation what is important in the in terms of the speed of coagulation what is important in terms of the strength of the clot what is important of the stability of the clot we begin to understand how role to integ is formed and then we also begin to understand what factors are involved to be able to know what we need to use to fix those parameters Okay so so yeah tell us about the start yeah so so the start um it's a very fixed idea and as last said when it was going through there's the r type and there's the CT time and it's just essentially the time to what we call two millimeters of amplitude intake it's called the r time or the reaction time in rotum it's the clotting time or CT now what I want you to know is that this diagram I have on the right is very simplistic okay one of the key things is that there are two different tests and so what's normal what's a normal art time is very different from what's a normal CT time and we'll go through that so in this diagram here it looks at the r and CT time are equal but they're not so let me make that clear they're different tests using different react reactants and because of that they're going to have different variations in terms of what's normal so this is a very simplistic diagram and because this is a um you know a real-time kind of Quantic head test and in a rapidly leading patients very important to have fast results is is there a sense of which one is better from a sport rotten's faster I get I get results on R and CT and then all the other results faster than tag so no so I our time is take so you get you get CT um you get the A5 a lot faster than um then take yeah take as we'll go through the reaction time actually takes a little bit longer with that with tape yeah good to know I mean it and it and when I say longer you know it's like a couple of minutes so um I guess it really depends on how those extra extra minutes um you know how they sort of factor in to your decision making yeah good good so Ben tell us about speed number two speed yeah so speed so speed is the time it takes from two millimeters to 20 millimeters of amplitude and intake it's measured as the K time or what's known as the kinetic type and in rotum it's known as the CFT or the plot formation time now what is really um I guess uh tied to this idea is is What's called the angle it's called the alpha angle and so the alpha angle is the angle from 0 to 20 millimeters amplitude and you can you can really say that the K time and the um and the angle are actually very integrated in terms of you know what they represent in other words if you have a increase in your K time so that it takes longer for you to um you know to go from 2 to 20 what you'll find is that your Alpha angle will reduce that that makes sense to you a lot doesn't it yeah it feels like they're absolutely proportional to each other correct yeah and so that that's why they use you know very synonymously and that's why the things that affect um the K time will also affect or sorry the K time and the CFT and the clock formation time will also affect the alpha angle as well is one used in preference like say you're making a decision uh I forget what the uh charts utilize I feel like Alpha angle is the thing the chance to utilized more so yeah so we'll go through it in fact now they don't use the um they don't use the K and and Alpha angle they use the hybrid of it and I'll and I'll tell you why in a second all right okay um so so the next one yeah next one is strength and I think that this one's pretty obvious isn't it absolutely yeah yeah so this one this one's strength is just maximum amplitude and intake it's called the um ma which is the maximum amplitude and in rhodium is called the maximum cloth firmness now now just quickly I've had it I've had a question from the chat which says is the alpha angle from um from from 2 to 20 or 0 to 20. now I think it's from 0 to 20 okay and you can see you can see it on the graph here that if you look at the alpha angle it starts from zero so it's from zero to to 20 here all right and but the K time is from two millimeters to 20 millimeters all right whereas the r time or the CT time is from the start to when you get two two millimeters of amplitude but if you look at the alpha angle it actually starts from from zero yeah I'm here okay like if it was it was starting from two it would you would have a line starting from right right here so I hope that makes sense you're gone okay I was just about to move to the next one how about speed and strength yes so this is what I think you and I see so there is a measure where you can combine speed and strength and you can see that's in between the um the the K and the alpha angle and the maximum amplitude and that's what we call the amplitude at five minutes or 10 minutes from either from either the end of r or CT or the start of K or cf2 or really it's basically from where um the two millimeters of amplitude um occurs okay so in Tech enrollment is called the A5 or A10 now what you and I see lie is actually the A5 I think that that's the one that you'll always see most commonly the numbers there and the A5 is really a hybrid between speed and strength and that's where you can make your decision quickly in terms of what products you need to use and I think you sort of mentioned that as well um you know getting those tests back quickly and A10 feels like it's a more accurate representative speed of speed and strength just takes longer and often not that different uh so it's not like yeah automatically at five to ten minutes so yeah that one there's at 10 minutes I think it really depends I think the one that um is in our algorithm is A5 yeah I think that's the one they commonly use yeah yeah um but but you know I'm sure some studies could use A10 and in fact you can use whatever you want you know you'll see a15 a30 a60 um and what those represents are the times in which they occur right so yeah so we've got we got start we've got speed we've got strength yeah but have a stability number four stability yeah it's the last one stability so the four s's so the the fourth of the S is stability and that's lysis now I've got license at 30 minutes but you can have license at whatever time so you know in this graph here you've got um biases at 60 Minutes as well okay but we commonly see it at 30 minutes so it's mice is at 30 minutes from the end of rrct or the start of K or CFT which is essentially this um when that when the two millimeters of amplitude occurs and in tag is measured as ly30 or cl30 so the l y stands for lysis the CL um stands for clot lysis you note in the diagram I have circled ly30 and ly60 this is an incorrect diagram in the cacp article okay rotum does not give you ly30 or ly60 the reason for that is Rotom gives you an index which is called l i it's an li30 because it's it's a clot license index so just be aware of that okay um yeah so we won't go ly30 we'll just look at l i 30 or 16. okay L I30 or li60 correct okay and that and just be aware of that um that uh it's talking about it um I think probably a you know a similar management but it's called an index okay and then the last part of stability is this yeah the last part of stability is maximum license I don't think you'll see this um you know but it is in Rotom and just describes that uh it's the percentage of decrease in amplitude from the maximum clock firmness you'll only see it in Rotom and um you can see in this graph here the maximum license is this you know this proportionate to your mcf right that sounds really good Stan so I mean this is the first part done and if I think you know whatever I use my hospital I'm going to memorize those numbers and that that system so I use rodem I'll be able to draw this in a tumbler glass shape I will then have you know one two three two and three and four as my variables to think about and then I'll just put some more values there and that's my first part I reckon I could get that down for the exam and hopefully you know you know three minutes that that sounds pretty reasonable um yeah and and I think if you think of it you know in those four things you know in those four S's and hopefully um that is an easy way to remember it start Speed strength stability okay that's correct and what we'll do now is we're going to go through some questions which I think will hopefully really help you memorize those key ideas all right that's good so so in fact why don't you ask the questions to to the audience yeah what is required for the start you know to start coagulation so let's see uh who's got a so we as we said this will go up on uh on the podcast on YouTube so anyone with a camera on and hopefully you're okay with uh being asked a question and for it to be on YouTube and this will just be really a discussion but hey do you want to uh let's go with um Christine if you're happy yeah Christine what's required broadly to start uh coagulation um an interaction between platelets and tuberin I yes um I haven't think about when you think about um the initiation phase of coagulation um what is it before that yeah coagulation practice coagulation factors yeah correct well done and and even thinking about it more specifically when you talk about coagulation factors what do you what what do you want to point to specifically that occurs at the start is it the thrombin burst that from a birth happens after because strummingbirds remember that um it thrombinus needs to have you know that Cascade occurring okay so in other words what needs to occur for that Cascade to to start going down specifically you would have to um I guess to create either the infantries or the extrinsic pathway yes excellent well done that's right that's exactly right so what is required to start quality coagulation is what needs to occur at the start of the intrinsic pathway and can I ask you you don't have to know but do you know what other factors or what's involved to the to start off the extrinsic pathway um so tissue factor is one and then there's another Factor um on that side five to seven back to seven excellent so it's the tissue Factor 7A complex that starts off the extrinsic pathway and that's really the most important one but we also need to think about the intrinsic pathway as well and do you know which one starts off the the internal pathway on the coagulation Cascade I think it's 12. yeah 12 to 12 8. excellent well done and then where do they all converge to um that factor 10A they become a common one wonderful correct the common pathway and then Factor 10A binds with Factor 5A and that's one um gives you that um thrombin okay well done and so knowing that if you had a slow coagulation or slow start to coagulation what do you think would be the issues there um I suppose why with writing you today is it the in term and the app term so you can or the X term sorry so you can see whether it's yeah and let's not yeah let's not go too much into I guess um the details of that we'll think about sort of at a very basic level um and then after it will sort of build on to it but you know on the on the basis of what you've described in terms of what is required to start coagulation if if it you know if you saw that the start of coagulation was really slow what does that imply to you just a hypercoagulable state as a result of either um coagulation Factor deficiency or for example like an anticoagulant medication good excellent and so what would you do to treat that um you could give ffp excellent because you want to give coagulation factors yeah well done and then the other one you can also give is prothrombin X as well excellent so you've done so well so look essentially when we think about starting coagulation this is called the initiation phase and I'm really trying to tie in the ideas of um the cell based model theory of coagulation here okay so in the initiation phase you really have the extrinsic pathway being activated which is that tissue Factor 7A complex but we also need to think about the intrinsic pathway as well which has Factor 12a okay that's less important but it's also present as well um and then they all converge to the common pathway where you get the factor 10a5a complex that um produces thrombin and so that if you have a prolonged K time or or CT time what you need to do is you need to treat that with coagulation factors so you treat that with either ffp or you treat that with prothrombin X okay and that's a really simplistic way to think about this now I think um you're going to say to me oh but people say sometimes to treat it with fibrinogen or platelets um look if you have severe thrombocytopenia or severe hypothyroid anemia yes it will affect this but the most common cause right is going to be low coagulation factors or as you said any potential medication specifically Heparin which um which reduces coagulation Factor activity when we do the um obstetric Rotom we always find that you know the typical patterns are you're clotting time okay time is really low but it's you know it's almost always kind of forbred engine lack and whereas if you have a trauma patient um this this this could be often the problem where you know you've got massive tissue fact activation massive extrinsic pathway activation and consumption of of uh of factors and therefore those situations almost always need ffp and prothomore and X's is that is that right um do you know I I don't know specifically in terms of the circumstances but um it yeah it makes it makes sense to me and um I think that you know with trauma patients oh look you know it's look it's very dependent because I've seen both happen in in both kind of scenarios um but uh you know I think you sort of treated on spec yeah in terms of what you actually see from the from the road from results I I you know I I must admit I don't go in with the idea that um that a certain class of patients has are gonna develop a certain type of coagulopathy and that's why you're doing the test anyway so that makes sense yeah that's right correct correct but yeah I think it's a really interesting point you make and perhaps something that um you know I think we can have that discussion in the future if we do um you know I guess find an article which looks at trauma patient and obstetric patients and see what kind of um uh patterns of coagulation is more um common with them yeah um on to the next question so what is required to speed up regulation um you might just ask uh Ben what do you reckon what's required to speed up coagulation uh so I think you need to have adequate coding factors um and then also sufficient um I don't know what you'd call them code quality factors like calcium yes yes so um I think that uh the the quality factors are important to start it now hypothetically right let's say we've got enough body we've got enough plotting factors to actually start the um the the reaction okay start the coagulation so in other words that your K or CT time is normal now we're looking at speed of coagulation so you've got enough clotting factors what would reduce the speed of coagulation so the number of platelets that you had yeah good so platelet is one and then what will be the other one uh calcium or factor eight I'm sorry I think if we were transitioning so um let's think about the coagulation coagulation Cascade essentially what we're producing after we go through the common pathway and we go um you know the factor 10a5a complex we produce thrombin don't we prothrombin thrombin what is the effect of thrombin so thrombin Cleaves fibrin uh sorry fibrinogen into fibrin and then also activate factor a to back to a yeah good yep and it also activates platelets as well okay because you made that comment as well so now we know that in the speed up of coagulation this is where the thrombin burst happened when you've got the thrombin burst as you said it needs to convert fibrinogen to fry burn so in other words if you were short of fibrinogen you are not going to be able to speed up coagulation okay and as you said the second bit was that it activated platelets and so if you don't have enough platelets this is also going to slow your coagulation as well and so this is where you sort of see where if you're um if you're Alpha angle is increased or your K time is increased um what you need to do is that you need to treat it with fibrinogen and or platelets and this is where the idea of fiptam comes in where you can sort of see what is it that causes the the slow and the speed up is it fibrinogen or is it platelets now which is more important here is fibrillage and more important here or platelets more important here Ben what are your thoughts I would be guessing and just say vibrant but that would just be a control you're correct yeah correct so in the speed if you look up if you look at the coagulation Cascade you know the thrombin birth you know the first thing it does it it moves sorry it clears fibrinogen to become vibrant so that's the first step so that's why fiberinogen is considered more important at this step here but platelets are also important okay but um that that is second all right well done okay next one uh what is required to strengthens I'm sorry I missed this page actually sorry Ella and then um obviously we've got to discuss the treatment because this is where it's very easy but the treatment for this if you had a prolonged K time or increased Alpha angle is to give fibrinogen either through cryo or fibrinogen concentrate if you use fibrinaging concentrate before that it would be a while back I've been an obstetric bleed patient but yeah gone yeah it's only it's only been a new thing in our department over the last year so I used it um for that recent trauma patient that I had uh last year and uh it was it was actually very good um so very very useful but you know if you don't have those if you don't have that concentrate there the primary place you get it from is from cryo okay and then the second thing that you can also trade with is um platelets that's fine all right the next step what is your question to strengthen clots and uh yeah so I might just get someone to answer that let's go with um uh Laura what do you reckon Laura what is required to strengthen plots I think um caught straight brinogen and platelets in the tag with the maximum amplitude yep and which one is more important here for our original platelets uh platelets yeah correct and specifically functional platelets okay this is this is where the idea of um where you sort of see the effect of anti-platelet therapy you really see it at the maximum amplitude phase all right and so this phase here the strengthening is really um what will be labeled the termination phase in your cell based model of coagulation and what it requires as you really as you said really well is number one in its functional platelets not just functional platelets it's the number of functional platelets and then the second thing you need is fiber engine so the treatment for this is we need to either provide functional platelets or provide a way for them to be functional again and might be a little bit of a tricky question but what could be a way what what drug can we use to I guess increase the function of platelets yeah vasopressin excellent ddavp well done China all right but yeah it's a little bit of a hard one there so dbavps sometimes used to increase um like activity this is quite common right in type 1 on Wheel brand deficiency where you know you've got um you know just a total deficiency rather than the rather than a quality of it so you can just give DDA VPN and uh everything kind of is is better yeah do you find like have you used it before it would have been a long time ago probably at the women's like yeah you know deviating was a type one is real relatively common whereas all the other really rare and disastrous forms of it uh you know again are much rarer so I don't really see that yeah I feel like I'm you know we've got so much Reserve with playlists you know unless you've got this patient with help syndrome or or some you know rare thrombocytopenia really you're seeing someone who's on Clopidogrel or or some other anti-platelet that you have to consider giving playlists or in spite of a normal play account well you know where I think it's helpful and you're right in terms of that there is actually you know quite a bit of Reserve in um with platelet function is when you concern that platelet function is actually not there even despite having the adequate platelet numbers which is why I've really put functional platelets there and we sometimes say that In Obstetrics you know with preeclampsia even you know with um they don't just reduce their function you know they don't just reduce the number of platelets but they also reduce the functional platelet activity as well um okay and then um yeah and then the second one you can often can treat them with is fibrinogen again cryo or fibrinogen concentrate last one next question what affects the stability of clocks and I might just get something else is around uh Matt Avery what do you recommend uh so I guess that's the strength of the body is the um uh platform I guess all breaking down of that cloth yep so enhance fibrinolysis little effect um that's right and so if you saw that there was excessive breakdown of plots what could you do to treat that uh so you want to give some anti-fibrinolytic therapy something like txa yeah exactly is probably the Mainstay now um uh Matt do you know how txa works uh takes a no I don't sorry yeah some uh plasminogen I think that's right correct in English you're right um and so the other one that I think that uh people might have heard many many years ago is a protonin but that's probably come off the market now because of uh its adverse effects um now there was I think there's a couple of questions in the chat that I'll just quickly go through um Ben says when you when you say increase Alpha angle for Speed you mean a reduction yes apologies you are absolutely right what I meant to say was a reduction in your Alpha angle so an increase in your K time would would lead to a reduction in your Alpha angle thank you Ben for um for spotting that mistake and and that says intake is the CL 30 30 minutes after maximum amplitude or 30 minutes after the start of confirmation it's 30 minutes after the start of plot formation which is at that two millimeter amplitude now um just quickly go through what Matt talked about and yeah so that was the um you know that question of li30 li30 is from the two millimeters plus 30 minutes or from zero so let's have a look I believe that cl30 is from the start of K or C of T So at the two millimeter amplitude in other words yeah so in other words I think the um assumption is that uh you know when we're having what we call the cl30 can also be called the a30 as well if that makes sense but the reason why we call it a cl30 is that at this point here what we're trying to reference is what that amplitude is versus the maximum amplitude now you could argue that at cl30 you haven't reached maximum amplitude yet which would be unusual um and that would mean that there will be some other coagulopathy going on okay but yeah good question and and yeah it can it can be a little bit confusing but uh cl30 and li30 is from 30 minutes from the two millimeter amplitude mark foreign now um I want to go through normal values because I think the examiner did make some mention of that if you mention normal values that would give you credit for that normal values are hard to reproduce in this exam specifically for roadsome I think they're okay for take so I've just given you some numbers here as you can see there's a variation of what's considered normal the caccb article has um some numbers and then I've got some other numbers from another article on PubMed you want to go through the numbers and see what the differences are yeah I mean just looking at this it it makes me think why would I even try to remember roton for this exam I mean these angles and things are really so anyway tag our time five or ten minutes that's very nicely nice to remember there uh we're a CT for all the different numbers they're both they both take they both take a lot so these are these are actually the same tests but I'm giving you two different numbers for the same test which is why you can see how confusing it is because wait till you see the next slide for Rotom that's even you know that that's even more crazy sorry yeah I was looking at the next one already yeah so we've got here five to ten minutes and four to eight minutes I mean these are these are in the Realms of similar so I you know yeah so I can ask you as a strategy right what would you do if you saw this you know if you saw you've got an article which says 48 minutes you you don't you know there's another article which says five to ten minutes yeah what do you do to bring to the exam examiners know this variability and or they should know this variability so I I would pick one and just memorize it I think close you know there's if there's variation in something it's not mathematically necessary to be correct then you just pick one and memorize it and then what do I memorize I memorize the one that makes the most pattern sense and so you may choose five to ten you know five and ten or you may choose four to eight because then the next one is one to four and then four seven seven four that's a nice little pattern there that you can memorize that is a nice pattern I agree I spot that out too yeah so really I I do what I'll do whatever is easier to memorize that makes more mathematical 10 cents and then yeah I don't even think you'd go as far as needing to reference this stuff like that's just wasted memory examiners don't expect that if it you know if you're a bit if you know if you're a bit um good at memorizing stuff and it just comes to you great you know that that could be impressive but you know I would just remember the one on the left because that makes the most pattern sense to me I'd agree you know like the ones on the left actually that you can actually find a pattern on um but you know I think just be aware of the one on the on the right and also maybe perhaps one in your institution as well you may still see it a little bit different okay um and then the l y the license 30 what you'll see is that what's normal is that you should only see a reduction of zero to eight percent at um at the 30 minute Mark okay and so that uh I think you might sort of see another one uh at three percent I think there have been studies that have shown that uh in trauma if you exceed uh three percent licenses compared to your maximum amplitude um you consider it higher risk and you should probably treat that so you might see some even more conservative numbers now there's a question in the chat when measuring mcf maximum clot formation or maximum altitude is the measurement the entire amplitude of the Rotom Tech graph or to the zero axis half amplitude yeah good question I think it's the whole amplitude so I think it's top and bottom okay and the reason for that I say that is just then just quickly um when you look at Force stability it says it's just got a diagram that shows arrows you know from those oh yeah you know yeah correct in fact in fact I would say sorry it's probably yeah the from from the zero so from halfway so I think I think maximum has to be from from from the zero point all the way to the top and any and if you see this graph here I think um what it's what it's showing is that maximum amplitude is from zero to up and then this is the mcf is from zero and these are absolute values here and yeah your slides showing um oh actually that's that's interesting look at no no but but because I think I think what it's showing is that if I if I was to just edit this I think this is why I was confused before you do that what other numbers to know so slide was it six or something what are the numbers to know it may be different so mcf may be different to Ma uh keep going up what are the numbers to no slide oh what are the numbers to know it's not yeah slide six or so keep this one here and I keep going all the way to the top like your slide number six oh slide number six yes yeah that one it may be different see how it goes m a versus you know mcf that they've actually got a different definition one might be the whole the whole amplitude and the other one might be from zero point just basically all right I'm not sure okay yeah I'm not sure interesting um so maybe take when they go Max Zoom amplitude is for the top and the bottom yeah and then maximum clock firmness is from the zero point that's a good point I'll need to I need to find that one out yeah I mean this one here this diagram here from uh the caccp article is probably not not sort of instructive on that I guess what we can do is if we can look here um the mcf so this is for rotor and the mcf is 50 to 72 so that's very close to maximum amplitude when you agree um what yeah and only the only problem is the way the solution is and the standardization so even though the numbers are the same I don't know maybe they are talking about different definitions of those points yeah again again I I don't know sorry yeah um I mean going by this so mcf is measured um in fact maximum clock firmness I think I think it's still measured in millimeters uh 50 to 72 it's just a different name uh for it and if it's 50 to 72 it's very close to maximum amplitude in uh in Tech so I think my provisional hypothesis and if anyone knows different please uh send us an email afterwards or put it into the chat if if maximum amplitude is from you know from top to bottom or maximum amplitude is from the um from the Zero from half from the halfway point it's a um a very very and to be honest question it's a it's a subtle Point as well like you know you put these numbers down you draw the diagram like yeah I don't think it's going to matter for the exam but yeah if you're on learning I mean we just read what the numbers say off the off the um of the chart of the computer yeah yeah very good um now now I wouldn't memorize Rotom okay for this specific um reason that there are so many different tests in rolesome you know there's extemp in tem heptam eptim FIB Temp and all of them have different values so I think it's it's a little bit more challenging to memorize um wrote them and I would just memorize TIG and I think that's okay it's funny how like even looking back and just trying to remember this number it's actually quite easy to remember you know four to eight one to four four seven seven four fifty twenty or something like that like yeah what's the pattern it's so easy to remember and and that's what take and then the challenge Now lies because of that so easily now to memorize uh Rotom yeah yeah that's great easy photography yeah no this this one here I think it's a little bit more challenging and and look for us so these are the ones that I think you'll see in uh in our practice in our institution and shout out to wa I think this is based on the King Edward Memorial Hospital numbers so um I think that if you do have a wa examiner I think you know use these numbers and so the numbers that are important there and I've and I've really summarized um some some just some key ideas here you you can see on if you if you have it in fact what we should do Lara is um I'll um I'll send it to you and then we should definitely attach it to this presentation here but if you actually see it on the um on the algorithm it's very it's a lot more complex but I've just picked out some really interesting ones which is that uh xtemct the normal one is less than 80 Seconds you can see how that's very different from your K time you know it's a minute 20 versus four to eight minutes oh sorry uh yeah sorry when I say cater I meant R time because this is the start of um start of your coagulation so intake your art time is 48 and here x10ct which is analogous to your R time is less than 80 seconds and then what Rotom has instead of alpha angle thought um firmness and I'm sorry clock formation and uh your maximum clock firmness is that they've got A5 so what they say is that uh what you want your x10a5 to be more than 35 millimeters in your FIB temp A5 to be more than 10 millimeters that's considered normal and then the last one for fibrinolysis which is clock stability is that you won't is that you want your X10 maximum license to be less than five percent so yeah interesting so um you can see how you can see how that they've adapted a lot of the numbers that we talked about and you know instead of um looking at the alpha angle uh the uh the maximum amplitude or maximum clock firmness they've used A5 instead which is that hybrid but you can see how they go through all those four things I talked about so you're talking about what starts off coagulation through the x10 CT what speeds up and what determines the strength of coagulation and that's determines through the x10a5 and the fifth M A5 and then what uh determines thought stability which is through the x10 maximum license number excellent does that make sense to you Laura yeah and again I mean it makes sense and I think the value of it is it's good that it makes sense but practically I I end up just having to look at the graph and the context really uh but for the exam yeah you know learn some numbers great it just add it to the pile of numbers you've got to learn yeah and and so look I you know I put that there just as a very as a as a slight that I don't think that uh you know if you don't remember the numbers I don't think it matters that much you know I think as long as you know the sort of the key ideas in terms of how the how the um how the diagram is formed you know with the start the speed the strength the stability I think uh you're on your way to definitely passing this uh question here yeah nice and this was the graph again I just wanted to show you that uh it's a very simplistic graph and at the r time in the city time are different okay so that the r time for take is 48 minutes and the city time has to be less than 80 seconds or 83 seconds if you see some other different algorithms uh there so for the next few slides down so we're pretty much going to go through different normal versus pathological States is that right yeah yeah correct so I've got a normal take here and I thought what would be really interesting to do just to consolidate all the information that we have here is to have a look at some different uh uh Tech graphs and see what uh we we think the patho pathology is all right so I've put the reference one on top there beautiful and just for everyone listening you know the reference one just looks like a nice essentially a cylinder uh it has a nice amplitude great easy reaction time and uh nice Max amplitude that doesn't drop off whereas the second one here the start is a bit slower the speed is slower and then the strengths of the max amplitude I am so has slightly decreased but the stability is normal in this one so what do you make of that we'll ask the audience on this one yeah sounds good that's the uh what do you reckon uh Olivia what do you reckon about this um so you've got an increased time to start and a decreased speed so I would think that's probably something to do with your coagulation factors being decreased and good yeah and and I guess um you know the question is why um why would you be less inclined to say it's platelets and fibrinogen uh so the strength are slightly decrease no I'm going to tell you if you are right this is primarily to do with coagulation factors yeah and and you know the question is why why don't you think it it has primarily to do with platelets and fire religion you mentioned it yeah I mean if it was platelets the maximum amplitude the strength would be so makes me think less likely platelets and more likely coagulation and know that they are interlinked everything is interlinked you know so in other words that uh if you've got low coagulation factors ultimately it is going to affect your the way that your platelets function as well as the way that fibrinogen becomes uh fibrin all right and that's why the strength is slightly decreased with um with a quaglopathy and you know what would be I guess a um a cause of a cause of this uh you could be on some anticoagulation medications excellent well done good job excellent so the next one we've got here so again uh the start here is normal the speed is slight is slower the strength is definitely decreased not just slightly decrease so the max amplitude is less but it doesn't drop away so the stability is normal what are you making of that it might go back to Ben so I would think that that would be a reduction in both platelets and plotting factors um so similar to what Olivia was saying before we've got a slower start which would be um clotting factors primarily and then the the platelets as well as impacting on the firmness of the quad I still work in Russian sorry yeah so um why did you say plotting Factor because the speed under the speed so to speed let them speed slower um yep so that that's why I thought calling factors although it does look like it's got a similar Alpha angle um so it might be um it may not be calling factors it may just be a platelet deficiency yeah and remember that if it's um what else is to fight with like sorry The Stance Noel yeah it's initiating the clock yeah beside's normal so so you know that the Stars you know quite regulation is um is hey Stan theoretically normal because that's your start but your speed is low and yes it is it's a platelet idea but also what's the other idea that we also need to think about as well yeah um sorry why were you saying I know you just cracked yeah fibrinogen exactly so oh I was just coming in and that was I yeah yeah but that's right it's back to normal I'll flag it if it happens again yeah yeah apologies I think some someone was trying to give me a call that's on so um yeah so you're absolutely right so the the two things here are going to be platelets and fibrinogen all right and it's very hard to tell the two apart um unless you use rosem where the fifth term excludes platelets and then where you can tell between the between the two all right whatever okay next one also this one is um definitely one you don't want to see since here the start is normal the speed is normal and it looks like this strength and the you know the max amplitude initially is normal but you get this very sudden drop away so very wrong one sorry no no you're right right sorry fat fingers fat fingers you know I'm not used to presenting And discussing a podcast at the same time as we were saying the strength is normal so that Max amplitude is normal but the stability Falls away rapidly so it's decreased and you can see a very you know you know very sharp drop away with a very elongated tail kind of like that the body leaf what do you make of this Christine um so I think this is participantolysis yeah correct well done and how would you treat this um you could give txa correct and what will be some of the causes of of this um yeah I see like a consumption type choreography yeah it's considering DIC and also if you can also see it if someone's been given um fibro fibrinolytics as well like literature as well we're done excellent uh so this is quite a kind of a fat Trace so you've got a start which is faster so short ROK time speed which is faster so max that Alpha angle is is higher and then the strength is increased so the max amplitude is higher as well but still and the stability is normal so essentially a square shape the whole way through um so what do you make of this and I'll just ask uh Laura again I I'm not um too sure but got your first principles it seems like a hyper coagul coagulable State well done yeah excellent I mean and I think that's one of the key things you know you you were you came in with this uncertainty but you've made the right application of the concepts there we've gone what can cause my um my clotting time to be faster will increase clotting factors or increase plotting Factor um functionality which means that they're hypercoagulable and that results in increased speed increased strength as well okay hold on can I ask you where where would you see this quite interesting uh oh yeah um just having a guess um so hypercoagulable States can be seen in um physiological States and pathological States so things like maybe maybe pregnancy but I'm not sure or um like malignancy um have you seen these uh shapes before no I haven't in real life so no we've never done it on say yeah like I was just trying to work through myself thinking where would this be and maybe like pretty pianist efficiencies and yeah lipid syndromes maybe but yeah I'm sure there's yeah some pathological conditions where you see it um I've seen it heterogenically where I've you know and I say inverted Commerce over Patrol my patient just with um uh excessive blood products so it's been a bit efficient with my blood product uh giving on on a patient and I've actually seen this graph been presented um I've seen it in pregnancy as well if you do it just before delivery because they've got lots of forbidity on board and that yeah that makes sense as well yeah excellent and then Susan how about this graph here what do you recommend this one so this one looks a bit like a bottle like a you know beer bottle maybe where the start is faster uh the speed is again faster so very sharp Alpha angle or a large Alpha angle the strength is increased but the stability it's it holds for a bit of time and then it drops off to make like a bottleneck appearance uh so yeah Susan go for it I'm I'm not I'm not sure so just describing what you see the dominant effect is the fact that it's fat and Tails off faster so you're starting off with someone who's slightly hyper coagulable and then breaks up the clock a bit prematurely so would you see something like that and DIC but I'm not sure perfect yeah exactly so this is I think what they call DIC stage one uh which is which you don't want to get into because pretty much this is what happens straight after I just showed now is the second well in the later phase of DIC so this is start is slower you're going to massively long kill our time the speed is slower it's it's a very thin if there's like one of those um party balloons that the uh make shapes out of oh yeah elongated so the max amplitude is significantly decreased and the stability is coming it's not clot yeah stability is not a not a problem at all yeah um but yeah this is uh stage two DIC that's bad except out of a uh out of a cheat sheet um which is practically what a lot of us will do but that's that was such a great time so I hope that gives you guys you know I think a framework to build on um you know build on your knowledge I think you can definitely add a lot more um you know Concepts to what I've presented today but hopefully that gives you a really sort of good frame and I think you know if you can reproduce all that in the in the exam paper I think it's a solid three definitely pushing to a four um and obviously if you if you include some of the other concepts related to rotor that's when you can get that five out of five but that is that is extremely challenging because of the uh the numbers involved and the different variations involved all right I just want to say I'm just really impressed with everyone answering those questions you know they're not easy questions and even working from first principles a lot of time you guys were just doing exceptionally well with that and I'll definitely remember this start Speed strength and stability type framework because um yeah yeah and and that's the first time you've heard of it too the four s's of stand or maybe maybe the five s's that starts withstand and uh and fluorescence and I love it yeah start Speed strength stability beautiful what what you need to pass this exam to just think of it that way that's right this is well you need to have the speed you need to have the strength and you need to be stable just so poignant Stan this is a black integan Road anyways that's pretty good um yeah and um and Susan I hope you I hope I'm answering the question I think you were pointing out to yeah that picture in uh in six just know that um I think sometimes some of the diagrams that are there you that you'll see out in the on the metaverse there may not be perfectly right um the information I've source is is all the ones that I've referenced from so hopefully that makes sense and and honestly um that is also why ly30 what is considered normal is zero to eight percent because 30 minutes after you know the start of two millimeters of amplitude very normal to not show lysis at all okay we can get some questions answering after we sign off yeah yeah absolutely hey thanks very much for watching and listening and this is your coffee break and thanks very much for everyone who volunteered answers that's really really appreciated to keep this really interesting and also challenging so yep please share with anyone who might be interested and we'll see you all next time bye now what's new with ABC's advantesia is that we're forming a whole bunch of very comprehensive courses for every stage of your anesthetic Journey from medical student to procedural skills from foundations in anesthesia as well as really important exam lectures and clinical anesthesia courses as well foreign