Journal Review in Trauma Surgery - Getting to the heart of the problem - prehospital resuscitative thoracotomy for traumatic cardiac arrest ===

Welcome all to our second episode of Behind the Knife Trauma Subspecialty podcast series. We're really pleased to have had lots of positive feedback towards our first episode in September, 2025, uh, stabbed in the back, which was a case review of junctional penetrating injuries. We're moving on now to an episode, uh, that's a journal review in trauma surgery. Just introduce the team again. I'm PR Raj. I'm a general surgery trainee in Edinburgh, uh, similar to PGY five and with me is rashe. I am Hin Catley, former Junior Clinical fellow, similar to PGY three at the Royal London Hospital, MTC. I'm currently enjoying a year overseas in Australia, working in emergency medicine before choosing a postgraduate specialty. We also have Max Marsden. Uh, thanks Rasheen. Uh, my name's Max Marsden, uh, completing the international flavor. I am across in South Africa at the moment. Just finishing a, a trauma fellowship, uh, at the, uh, Chris Honey. Uh, Barron Academic Hospital in Johannesburg, uh, and I'm pleased to be

joined by Mr. Christopher Elwin. Thank you, max. Hello everyone. I am Chris Elwin. I am a consultant or attending trauma and vascular surgeon at the Royal London Hospital. Uh, and I also co-lead an MSCA Master's program in trauma sciences at queen Mary University of London. And today I am delighted that we have an extra guest. Uh, the lead author of our chosen study Mr. Zane Perkins. Same. I, yes. I'm Zane Perkins. I'm a consultant. Trauma surgeon and general surgeon at the Royal London. I work with Chris, um, and I'm also a consultant for the pre-hospital service here in London. Fantastic. So thanks very much for introducing yourselves and thanks very much Mr. Perkins for joining us as well. We're going to summarize our chosen paper and then dive into the practical and somewhat ethical questions as well. Scoop and run versus stay in play. Who should be performing pre-hospital for economies? Uh, the reproducibility of our outcomes in other systems. Potentially the role of diagnostic aids, like

ultrasound, the all important question of patient selection and then what we can do to try and control for confounders that may have changed results as well. So let's get started. Rasheem, would you mind giving us a short summary of the paper? Yeah, so the paper is pre-hospital Resuscitative thoracotomies for Traumatic Cardiac Arrest. Um, the population of the study is a retrospective cohort of 601 patients who underwent pre-hospital resuscitative thoracotomy by London's air ambulance. Between 1999 and 2019, this is in the context of 45,647 injured patients to whom London Air Ambulance were called to attend, of whom 3,223 suffered traumatic cardiac arrest. This means 1.3% of traumatic cardiac arrest patients underwent a pre-hospital resuscitative thoracotomy. The median age was 25 years old, and 90% of patients were male. 88% of the injuries were penetrating

with 74% of these penetrating injuries being non ballistic. The incidence of penetrating trauma increased from 11% in 1999 to 32% in 2019. 80% of pre-hospital resuscitative thoracotomy patients were already in traumatic cardiac arrest on London Air Ambulance team arrival. Four key time points were collected in the data, the initial emergency call, the onset of cardiac arrest, the time the London Air Ambulance team made patient contact, and the time of thoracotomy. The intervention. So the physician led prehospital resuscitative thoracotomy performed on scene using a rapid clamshell approach with Peric cardiotomy internal cardiac massage, manual aortic conclusion, and evolving adjuncts over time, including prehospital blood. Outcomes of the study, the primary outcome was survival to hospital discharge. Secondary outcomes included survival to hospital admission

and neurological status at discharge using the cerebral performance category. The key results of the study, the overall survival to discharge was 5%. Five. Statistically significant survival prognosticators were found, firstly, the cause of traumatic cardiac arrest. Secondly, duration of traumatic cardiac arrest, and thirdly, rhythm at the time of cardiac arrest. Fourth, the need for internal cardiac massage, and fifth need for adrenaline infusion. The last three can likely be all encompassed into cardiac rhythm. At the time of pre-hospital resuscitated thoracotomy, 105 patients had cardiac tamponade. 418 patients had exsanguination, and 72 patients had a combination of both. In cardiac tamponade, 21% survived in exsanguination 2%, and in combined tamponade exsanguination, there were new

survivors. Time from arrest was critical. Survival at less than one minute. Traumatic cardiac arrest was 16%. One to five minutes is 9%. Five to 10 minutes was 2.6%, and over 10 minutes was 1%. PEA at the time for pre-hospital resuscitative, thoracotomy had a 16% survival. Whilst agonal or asystole survival was 2%. The limitations of this study is retrospective design. There's been evolving practice over 21 years. Selection bias in who Resuscitative thoracotomy being based on strict indications and clinician decision on offering pre-hospital resuscitative thoracotomy. Potential attribution bias for cause of arrest, unlimited generalizability to systems without physician led pre-hospital teams, or high non ballistic penetrating trauma volumes. There were also only four tamponade patients with blunt mechanism of action.

So thanks very much Rashe. Um, Mr. Perkins, would you mind quickly describing to the listeners what is pre-hospital Resus thoracotomy and what are the operative steps? Yeah, no problem. For the whole duration of the study, the procedure's been very standardized and we use a single technique. We use the clamshell, um, approach. Because this has a number of advantages. It gives you wide access, allows lots of light in, uh, allows a, a view of all the organs that, um, non-surgeons would be used to. And we also use very basic instruments. So, um, we've, we've don't have a massive thoracotomy pack like you would have in the operating theater. Just some simple, um. You know, scalpel, scissors, um, Spencer Wells, a few, few bits essentially has four steps. So most patients would have already had their pleura decompressed 'cause that's part of our, uh, standard approach to someone who's

peri arrest, or if we think they have a tension pneumothorax. So the first step then, uh, in this procedure is the clamshell, opening the chest. Uh, the second step is opening up the pericardium, which is the, you know, the. Main reason for doing this procedure. And then third is dealing with the wounds you find. And again, we've, we've made this as simple as possible considering the people who are gonna be doing it. So, um, we are not trying to teach people to, to pledged repairs of myocardium. It's a, you know, the skin stapler to close myocardial wounds zinsky clamp to close any kind of thin walled wounds. Um, and then. Focus on really high quality internal cardiac massage, which would entail also aortic occlusion that we do manually. We don't try and put any clamps on the alta and, uh, volume resuscitation. See, it sounds like, uh, essentially trying to make it as accessible as

possible. Is there any role for external chest compressions in traumatic cardiac arrest? Well, so I suppose that really depends on what's called the traumatic cardiac arrest. So yes, there's a role for external compressions in things like traumatic asphyxia and hypoxic reasons for in being in cardiac arrest. But certainly external compressions are gonna be very well, they'll be ineffective if. Blood flow through the heart is obstructed or if there's no blood to pass through the heart. So your hemorrhagic or exsanguination patients that being said, so is internal. Cardiac massage, ineffective if there's, you know, no volume. Um, but yeah, we, we, we often. Say that in the majority of the patients we are seeing are either exsanguination or tamponade, and in those cases, external compression isn't gonna be effective. And was there anything else you wanted to add about Rasheen summary before

we moved on? So no, uh, that's a good, a good summary. I suppose what's worth saying is just our insights as a service, uh, and, and also the reasons why we were doing it. So, um. I think one is about timing, and I think it's quite clear from the data that patients who are in traumatic cardiac arrest for more than a few minutes have a dismal prognosis. So the idea of. Taking someone to hospital for something to be done in traumatic cardiac arrest doesn't hold. 'cause we know what the outcome's gonna be, that it's gonna be futile. The other is these. You know, we, we, when you write a paper, you've gotta be honest about your data. And we did that and Rosen quite correctly presented the outcomes for that whole group. But essentially within that group you got two different groups of patients. You got those that had a tamponade and those that had bled to cardiac

arrest. And, um, what we really wanted to show is. How different these two populations were and how important it was to target this intervention. 'cause essentially, resuscitative thoracotomy is a treatment for cardiac tamponade. And I think that's a, a key point that we're going to come back onto later on and trying to find out actually how can we better diagnose tamponade and try and find out who's having examination and maybe, you know, thinking twice about offering them this intervention if they've not got tamponade as well. I suppose the, the. Question that you've just brought up is actually, I remember reading in this paper that you'd cited about 90% of traumatic cardiac arrest don't survive because they've not been able to get to a surgeon in time. Uh, and I know the paper also strongly suggests that the shorter the duration of traumatic cardiac arrest before resuscitative thoracotomy, the better the odds of survival. It seems that pre-hospital, resus thoracotomy is really an intervention to bridge this gap between either

getting the surgeon closer to the point of injury. We're trying to reduce that time to get a resus thoracotomy as well. It seems really likely that these patients aren't going to survive the journey to Ed or to the operating theater either to have a good outcome. I suppose a question for all of us is, do we agree that without the pre-hospital Resus thoracotomy, probably all of these 30 survivors, uh, 23 of whom had a favor neurological outcome as well, probably wouldn't have survived their injury? Yeah, I mean, I think that's a, a really important question Prash, and certainly the data would suggest these patients really would struggle without that prehospital thoracotomy. And I guess if you had to sort of characterize the argument for, uh, scoop and run people would say that, you know, the definitive surgical repairers in hospital and you know, staying and playing and on scene interventions just delay the transfer to definitive care. The, the article references

quite thoroughly data that explores the two approaches and, and, and ideas like, you know, some urban systems in the US I know have started to, or have been doing quite some time putting patients, uh, into the back of police vehicles and moving them as quickly as possible. But, you know, I think this. This data supports the fact that when traumatic cardiac arrest has already occurred, transport alone and going as quick as you can is, is just not enough. And the outcomes are unfortunately still, still futile. As Dame was saying, you know, for tamponade, the definitive intervention is definitely immediate pericardial decompression and repair of the cardiac injury. Uh, and if you can do that on scene within minutes. Then I think, you know, this data shows that you can ver convert an otherwise unsalvageable paper patient into a survivor. Yeah, I agree. And I think as Zane has already, uh. Put it very nicely. There are, and you max, you know, there literally, there will be some people who you

cannot get away from the scene, but that obviously is very time and context dependent. We are very lucky in London being in an urban environment with the London's air ambulance being able to, to provide somebody with a skillset for those patients. So staying and playing sometimes. Is the right decision making, I feel? Yeah. So our management approach, certainly at London Ambulance for penetrating trauma is actually a scoop and run approach. We absolutely try and minimize all scene time, uh, and interventions and rapidly transport these patients to, to an appropriate major trauma center. The only kind of intervention, I mean, we rarely focus on doing the basics well like. Packing, uh, wound tracks and stopping bleeding, but much of that, uh, and identifying all the injuries as

well. And we do almost insist on having intravenous access 'cause we carry blood. So is that if you don't have intravenous access then you, you don't have a really, um, effective intervention available. But we try and keep our scene times. To, you know, a few minutes at most. The problem is though, is if you do all of that and you are on your way to hospital and they do arrest, then what do you do? And just carrying on to hospital with someone who's got no cardiac output. You don't get any survivors. So that's the time when we would then stop and uh, uh, and, uh, resuscitate these people. So we are only applying resuscitative thoracotomy to patients who've actually arrested. Um, and I think that's quite. Important to realize is the vast majority of cases we see, we taking them into hospital very quickly. Because we fully realize that rather have your arrest

in the hospital, you'll have a much better outcome or have no arrest. And so based on, you know, this logic and all the points you've all brought up, do you think there's any other surgical interventions that could be brought forward into the pre-hospital space? So I've got a question for Zane which may well be what a lot of people listening to this are asking. If you've not got the skillset available, what is wrong with sticking a needle in and trying to suck out some pericardial blood? Is there an option for that? As you are trying to get somebody to definitive care? There's better things you can do than try and stick a needle in and suck out a clot. And all of these are clotted, so, so. One, it's very hard to make sure your needle is in the actual pericardial space and not actually in the heart. Two, it's always clotted, so you're not gonna be able to aspirate it. But what is effective, and I think we'll come onto to it later, but if you volume resuscitate these patients, you can buy yourself some time. So

tamponade, patients do respond very well to volume resuscitation. Obviously it's not a definitive treatment, but it can buy you. A few minutes. So I would, uh, probably say to spend any effort on trying to do that than to try and, uh, aspirate blood outta the pericardial space. Would you give, uh, crystal Lloyd? Well, again, that's, you know, down to what you've got, but if that's all you've got, then that's all you've got. It's not the best volume replacement fluid, but, uh, it's better than nothing. Okay. So I think in the last few minutes we've essentially tried to justify the reason why this intervention's being done pre hospitally, which is there's just not enough time to get them to the hospital in some scenarios, especially if they've arrested. So moving now onto probably our most controversial topic of the um, podcast. I'd be interested to know what you think about who should be making the decisions to do a pre-hospital, uh, thoracotomy. And and then from that, you know, who

should be doing the operating. Could you describe to us saying how, um, this works in the London's air Ambulance? So who is in the team? Uh, how are these clinicians selected? And, and then who does the, um, the, the thoracotomy? The service has just under 20 consultant physicians that are permanent with the service. And we also. Have paramedics from the London Ambulance Service, uh, working with some senior paramedics that are permanently with us and other paramedics. They, they, they come to us at a very senior stage in, in their career. Uh, but they would stay for a year or sometimes a bit more than that with us. And we usually have at any given time about six, um. Registrars from all over the world. Come and work with us for six months to a year. So on the whole, the makeup of the team is usually two doctors and a

paramedic. There are some shifts with just a single doctor and a paramedic. Uh, the doctor for this particular intervention is the doctor who undertakes the actual surgery, and the paramedic will then manage the scene and airway and the other elements of the resuscitation. Like I say, the most of the doctors are consultants either in emergency medicine, anesthesia, intensive care, or surgery. And that being said, most of the registrars are also already consultants in their own specialty, usually from the same specialties. And I guess Zane teaching this is, is a real issue. How do we train, well, how do we train surgeons? Let alone non-surgeons to perform this high stress, low volume surgery. So for example, maybe how many, how many Thoracotomies might an LA, a physician be exposed to

per, per annum? Yeah, it's a good question. And one we've actually spent a lot of time on. We, we are quite a high volume for thoracotomies. We do about 50 a year. Um, so that's about one a week. Now there's two elements that you've gotta train and we've kind of. We train them together, but we've also decoupled them so you can focus more on them. There's the decision making around doing it, all those cognitive elements to it. And then there's the technical aspects, so you have to master both. Now, the people coming in we have a crew course. It's an intense week of training. It goes through lots of elements of resuscitation, um, but including this, how the actual team work together. Then all the new, um, registrars will spend a minimum of four weeks in, again, quite an intense supervised training period during which time they would need to take our

standard operating procedure for resuscitative thoracotomy. Read it, understand it. Discuss it with different consultants, make sure they really understand it in depth, and then move through that four week period to eventually getting tested on it and signed off that they know all the elements in it. Um, and that's about the decision making aspects and also how the procedure is done. 'cause as, as I was explaining earlier, we have a very standardized approach and then separately we run a skills. Training fairly regularly. And, uh, at that we have PO sign models and all the focus is just purely on the technical aspects of doing those steps of the procedure and getting, you know, getting used to them knowing what all the. Tips and tricks are for each of those steps. So that's how we, um, aim our training. And then there's a reasonable, you

know, we are quite a high volume service, so there's a reasonable number of real cases coming through that all of the resuscitated thoracotomies will go through our governance process, which is a. Which, where they get discussed. So the whole team is usually available to discuss those cases and we discuss them in detail. We have, you know, a decent amount of time to really, uh, talk about them in detail. So that helps maintain these kind of skills at the top of your mind. Yeah, so I mean, using a, a. Sign model, I guess, is, is relatively cheap, isn't it? And relatively reproducible for, for training purposes. I mean, obviously the, the whole, um, non-technical skills is absolutely crucial as, as you said. But the technical skills, do you think there's anything coming around that, as long as their ambulance might prefer to use for technical training, is there options for high, something higher fidelity that could be used to,

to help? I, well, I think we have a nice mix. So we have mannequins that we use for mooz training. So human, you know, mannequins, it's, and in those kind of training sessions, we try and really test all the other aspects of how you do this. So. You wanna really create the environment that this is happening in crowds, noise, you know, things that you, you know, wouldn't be used to in a nice, clean, well lit operating theater and how you manage teams, people you don't know, people that wanna help other ambulance crew and where you put the equipment and how you set yourself up to be able to do this frost. So we can do mo lodges where, you know, we give people. Incident and then they, and then they practice all those kind of aspects. But then we would essentially gloss over the technical aspects of, of the procedure. And then separately, when we do the, the PEG models, we leave all that kind of.

Decision making and team working and you know, working in a pre-hospital environment aside. And we really focus in on how do you hold your scalpel? Where are you gonna cut? How are you gonna make sure you're in the right place? What tissues do you need to cut? What tissues you don't need to cut? And. People can do that over and over and over on the pig. It's really cheap. I think a pig thoracotomy model is, is actually very good for training on, uh, surgeons will know that, you know, in the abdomen, maybe less so, uh, but in the chest, the feel of cutting tissues and dissecting them and that is, is pretty, uh, accurate. Can I just ask Zen, it's um, obviously I have had my trauma training in London and have grown up, and I'm a product I guess, of seeing these patients come in with clamshells. I, um, I, I mentioned this approach here in South Africa and, um. Was looked at incredulously that I would consider cutting across the sternum. And that, um, their opinion was, you

know, everything should be done through a left antola if you are either trying to fix the heart and extremists or clam the aorta. Um, how important do you think the approach is that the clamshell approach for that pre-hospital environment? Yeah, that's a good point. I mean. I, I think it's really important, a, a lot of these people will be doing the procedure on, on a human for the first time, and we want them to be able to, if they are genuinely a patient that could survive, we want them to have a really high chance of surviving and. Just going back to the summary and, and so sometimes not that easy to see it in the paper, but the people we want to survive are the cardiac tamponades who arrest in front of you. You know, a large portion of that cohort had already arrested before we got to them. I. We'll still try and save some of those, but that's not the group we are like really focusing on. It's the, the ones with the tamponade that rest in front of us and actually our

outcomes for that group are over 50% survival. So, and that's the group we're trying to. Focus on now. We want someone, even if they've never done it on a human, if that happens in front of them, we want them to be getting a survivor in that patient. Doing it through a left lateral, although you might cut down a few seconds on getting in the rest of the procedure's gonna be incredibly difficult for someone who's never been inside a chest before. Where the clamshell really makes it very, um, easy to. To see what you're doing and to find injuries and to treat them. I trained in South Africa and I was, you know, far more comfortable doing left lateral thoracotomies. And I've changed my practice though, having done now literally hundreds across here because it is. So effective, and I don't think, uh, the downsides outweigh the benefits. I think I agree as, as well. Entirely Zane. I think you've gotta be practical, you've gotta be what

works well in, in our, in your own system, and equally having trained. For some of my time in, in South Africa, you get used to a certain way, but yes, I agree in terms of, for, especially for non non-surgeons coming across the sternum is the only thing that makes sense to me. Albeit obviously with consequences that we have to acknowledge. But, um, you know, I'm in a, in agreement with you. I think we've, uh, discussed that pre-hospital re recessive thoracotomy is essentially ideally physician led in a high volume system. There's rigorous training processes and assessment processes as well to make sure that the people doing these interventions are rightly skilled for it as well, and as well supported as possible. We've also talked about the advantages of, um, a clamshell approach rather than a, a lateral thoracotomy as well. I suppose the next question to discuss is that. These results may not be generalizable everywhere.

London benefits from a established major trauma center, which is about 13 years old. Both the delivery and the um, funding of healthcare is centralized by the state, uh, including pre-hospital care. And it means that all the hospitals throughout the city and southeast England have coordin. Trauma care extending from pre-hospital all the way through to rehabilitation at the London Ambulance Service MHS Trust coordinates all pre-hospital responses across the London major trauma system. A dedicated paramedic in the control center triaging and allocating resources. Uh, to the 5,000 plus daily emergency calls. This includes dispatching, London's air ambulance to the major trauma cases. Just to talk about generalizability rashe, would you mind recapping the average times to pre-hospital response in this paper from the time of the emergency call? The medium time reported to traumatic cardiac arrest was 12 minute. The median time to London Air ambulance arrival was 20 minutes, and the median time to

pre-hospital thoracotomy was 22 minutes. This means at the time from traumatic cardiac arrest to London Air ambulance arrival was likely around eight minutes and the time from the London Air Ambulance arrival to pre-hospital thoracotomy was around two minutes. And the all important time from traumatic cardiac arrest to pre-hospital thoracotomy was around 10 minutes. Uh, max, Chris and Zane, you all have experience in working in trauma systems away from London. Um, I know you've all worked in South Africa. Um, do you think these timelines are currently achievable in settings away from London? And are there any settings in which a pre-hospital for colony should not be attempted as a standardized intervention? I think it's important to say that this paper and uh, well, it'd be interesting to say, see what Zane thinks is not telling other systems what to do. It's saying what is achievable if you've got the resources

and set up that we are very lucky to have in London. From my experience, no, it probably isn't reproducible in many other. Systems that I am familiar with, but. I'm more than happy to pass that over to Max and Zane to see the more contemporary feelings of that. I mean, I, I can jump in from a, from a military perspective, I had a sneaking suspicion I might be asked something like this. So I did, uh, go away and swat up on a, a couple of the papers that are produced. And I guess what you have to make sure you're doing when you look at the other literature is comparing. You know, apples with apples. So, from a South African literature perspective, i, I, I can't see anything written about pre-hospital thoracotomies in the, in the review. I saw, I, I dunno whether they're happening. But, but certainly in, from my experience, I haven't seen any providers performing pre-hospital thoracotomy from the military literature. So, Johnny Morrison published a paper in 2013, um,

of the, uh, I think it was 65. Thoracotomies that the Brits performed in the Afghanistan conflict of which just under 30 were performed en route. So that was in the Chinook. MERT team, so medical emergency response team that flew out in the helicopter. But what, what's so great about the paper we're discussing, what's so great about Zane's paper and I think is missing in some of the other reviews of thoracotomy is, is this really precise timeline data. And, and certainly we don't have that in, in that military cohort, so I think it's very difficult to compare and, that trauma system, the, the, um, the military, the British military Afghanistan trauma system might need to be replicated again. So, uh, I think it's, it's been and gone. And so yeah, it, it, it's difficult to, to make comparisons, I think. Yeah, I think, um, definitely a service needs to. Have a look at whether there's

a need within their service, like a gen, like a, a measurable need. Uh, and that need is are they seeing patients who are gonna have a cardiac tamponade, which essentially a lot of that is penetrating trauma. And are they able to see them in a timeline that fits? Because think what isn't realized and isn't. Clear is the training and governance burden of being able to deliver this kind of intervention 24 7 with successes is huge. It's continuous, basically. So, um, I think systems where. They might only come across a patient like that, you know, once every five years or more. Should really think about heart. 'cause it's a huge expense to try and keep an entire, um, team of clinicians. You know, able to get to deliver it. That said, the places where you're probably gonna see the kind of

people that need this all gonna be big cities. So urban, you know, areas where there is penetrating trauma. Um, and in those areas, usually the response times can actually be quite short. So I don't think we are the only. Place in the world that needs such a system. But, um, I think, I think there are other places that probably would see enough to be able to make it worthwhile. All, all the training and education and governance and, uh, that you need. Okay, so I think so far we've discussed, uh, what is a pre-hospital res recessive thoracotomy, who should do a pre-hospital res, recessive thoracotomy, and also in what setting should we be aiming to even do this intervention? Uh. I suppose our next big question of the night, which is probably the focus of this paper, is who should get a pre-hospital resuscitative thoracotomy? I suppose patient selection is very difficult, and as Mr. Perkins mentioned earlier

on we said this is really an intervention for cardiac tamponade, and the study highlights that the cause of arrest and the duration of. Traumatic cardiac arrest is the strongest predictors of survival. It seems that mainly patients who are having traumatic cardiac arrest within about 15 minutes or so of the, of a penetrating mechanism of injury who have got tamponade and most likely to benefit from this sort of operation. Ms. Perkins, is there anything we can do to predict if someone is likely to have a cardiac tamponade rather than exsanguination? The, that I think is important and we've been working on that quite a bit to be much clearer on our indications for this, uh, procedure. I think it comes in also in how, how the procedure was used over, over time. So if we go back, um, not that long, 10, 10 years ago. People in traumatic cardiac arrest, they would, you know, likely could be tamponade or

exsanguination, but we only had an effective treatment available pre-hospital for one of those causes. So you would give the, you wouldn't need to try and distinguish between the two because you would give the patient the benefit of the doubt. You had the capability to treat one of the diseases. So you look for some, back then anyone who had a penetrating chest injury. We would, and they were within a survivable time window we'd do with thoracotomy, because if it was a tamponade, then they'd have the best chance of survival if it was exsanguination or we knew they weren't gonna do well anyway. But what's different now is we carry, like we carry about two liters of blood on us. So we have very good treatment for the hemorrhage patients as well. So now more than before, it's really important that we define those two groups because. The patients who are bleeding don't do well if they get a thoracotomy, but they do well if you give them blood and try and stop

them from actually arresting. So we spent a lot of time on trying to. Rapidly define those groups apart and how the, you know, research goes, you go back and it's all actually out there in the literature from, you know, 40, 50 years ago, we had a look at all our cardiac arrests, where the stab wounds or gunshot wounds were and what was the source. And what we found was anything in the anterior cardiac box or the epigastrium. Was more likely to be an isolated tamponade than it was to be exsanguination, and anything outside of that box was far more likely to be exsanguination than tamponade. So that's made it a little bit easier for us to, target our therapies more accurately now, so, so we, we wanna target thoracotomy for the tamponades that risk, and we wanna target large volume blood resuscitation

and rapid removal to a trauma center for the ones that are likely to be bleeding. I mentioned it earlier that volume resuscitation can buy you a little bit of time in the tamponade patients. So what we in our updated SOP, after this research, if the injury is outside of the cardiac box and it's more likely hemorrhage, we would then prioritize access and blood transfusion. But then look for the tamponade with ultrasound. And if you find a tamponade on ultrasound now, then obviously change the direction of your treatment and, and perform thoracotomy. Okay, so that's really useful. So we were talking about ways to try and find out who are the patients who are having tamponade, and also how the SOPs changed in terms of people we think might be San Grating. It's really interesting to hear the role of ultrasound there, where actually, if it's outside of the cardiac box, you may have a, a look to make sure that they're not actually a tamponade patient. Uh, and we've discussed

that it's probably not worthwhile doing an ultrasound for everyone, given it takes too long, and timing is key for this intervention. I suppose the next question, we've now spoken a bit about who should get a pre-hospital thoracotomy and also who shouldn't. The survival rate from this paper is 5%. Rasheen, do you want to, uh, talk a little bit about the futility aspect? Yes. So talking about futility at a pre-hospital, thoracotomy is clearly a very high stress and emotionally charged intervention for pre-hospital teams and also bystanders or any other emergency services who are witnessing the event. Knowing that a 95% non survival rate is the current marker of success, um, I guess is, you know, Zane, Chris, and Max, is there anything that. From your experience in the London service has been put in place to rehabilitate practitioners and bystanders who've been involved in pre-hospital thoracotomies? Yes. Thanks,

ine. So firstly, I suppose based on this data, we've changed our indications for the procedure. We now really target cardiac tamponades and our. The rate of doing these procedures has actually dropped off quite significantly. So it's. It's effective, our change. So that will have the effect of not exposing as many people to futile procedures. Now we are also removing the people that are, you know, outside of a survivable window more aggressively. So if exsanguinating patients who are asystolic, or patients who have been in arrest for longer than 15 minutes. So that gets rid of a, a reasonable group too. For the ones that we do do, I think there's a few things that make it a bit easier to deal with these, uh,

emotional side of it that is, is when you're doing it for the right patients who genuinely have a good chance of survival and it's a lot easier to. Cope with that aspect of it. Uh, we do discuss these cases, uh, as I've said, uh, um, and we do try and get the wider team involved, so not just the London Day ambulance crew, but if we discussing it, we will also invite the ambulance service people that were involved. And at those meetings we do have a clinical psychologist who attends and, and understands how we work and is able to probe and check that everyone's okay. So I think. Much better than what we were, but obviously not perfect. We don't get to people that were maybe bystanders or in the, uh, ambulance service or air ambulance side of things. Okay. And would you mind telling us, since this paper's happened, how has the, uh, London London's air ambulance indications for a pre-hospital Resus thoracotomy changed?

Yeah, so. When we started in the 19 early 1990s, it was for suspected cardiac tamponade. In cardiac arrest for less than 10 minutes. And then that grew over time to be more penetrating chest trauma. So far more mechanism based. So if you were in traumatic cardiac arrest with penetrating chest trauma and the time window also expanded to 15 minutes not just based on our data, but based on international data. And now we've essentially looked at this in detail and. Moved back a bit from that and gone back to a pathology based indication where it's cardiac tamponade within a survivable window. We haven't completely removed the exsanguination. It's a relative indication, but it's for exsanguination in the chest that's not responding to high volume blood

resuscitation Thin. You know, there is that option to also see if you can control the bleeding surgically, but that's a relative indication. We don't do it that much. It's mainly there to target the tamponades. Zane, you obviously have an in-hospital practice as well. And I wondered whether you can translate the findings from this study and their indications for thoracotomy pre-hospital into your in-hospital practice. Or do you need to a, adapt the decision making for thoracotomy if you are working as their, as their on-call trauma surgeon? I think some aspects are translatable easily. I mean, the timelines are all the same, but I think as a trauma surgeon, a lot of the thoracotomies we do. Firstly are self-selected, the fact that they've made it alive to an operating theater and, and then a lot of them we are doing on live patients, so that's different. The traumatic cardiac arrest,

I tend to now in hospital, treat them the same as I would pre-hospital with this. This kind of approach. It's uh, it's simple. It's a proper damage control approach. You're going straight to the heart of the problem and doing nothing else. Um, and, and as fast as you can. And yeah, I, I suppose the other, um, aspect that we didn't talk about earlier that goes with your question Max, is. We've looked at a lot of the data out there, population level data on penetrating cardiac injury, and it's at least nine out of 10 people with a penetrating cardiac injury. Die and almost all of those die pre hospitals. So we, we, we are not getting, you know, the ones we see in hospital is a, there's a huge selection bias to it. And a lot of the literature that's out there has a huge selection bias. 'cause it only includes people who've made it alive to the hospital. So, there are differences. You can't apply everything.

But, uh, um, yeah, the, uh, so for traumatic cardiac arrest, my approach is. This simple clamshell, thoracotomy. And for live patients it's a median tenotomy usually. Thanks. I mean, that makes, that makes complete sense and I think it's something that, you know, us. Clinicians that work in, um, in the hospital setting can sometimes be blinded to the fact that the patient, uh, group that we see, um, as you say, has a, has survived to, to arrive in hospital. Uh, and if they haven't had the benefit of a pre-hospital physician, then yeah, that is, that is a, a, a different, uh, patient cohort. So thanks that, that makes complete sense. So, something I wanted to bring up was this time period was, uh, over 20 years, and during that time period, the London's air ambulances developed the ability to give blood products. What have you noticed in terms of your data with the difference between giving blood and not giving blood for your outcomes? Yeah, it's, it

um, again, very insightful. So probably the most important thing when I is. Blood is a really, really effective treatment for people who are bleeding. Makes complete, it's obvious, uh, uh, but what we've noticed is we prevent a lot of traumatic cardiac arrests now from Exsanguination. So if we arrive to people and they haven't arrested yet, uh, and we recognize they're bleeding and give blood, and we, we see very few witnessed exsanguination cardiac arrest now. So it's very effective in preventing cardiac arrest. But what we did find as well is when we compared people who had an exsanguination cardiac arrest and got blood versus those that got given OID or whatever. In the earlier years of the study, there wasn't really any difference. So to me that shows that, you know, you've gotta. The aim of the resuscitation must be to try and prevent a cardiac arrest,

especially from exsanguination. Once someone's arrested from Exsanguination, nothing really works to bring them back. Um, and that's quite different from the tamponade patients where, where there is still a window, even once they're in arrest. So I think, uh, over the last 35 minutes, we've now discussed this paper, which looks at outcomes from pre-hospital, resus thoracotomy. We've discussed what it is, what setting it should be done in, who should be doing it, and who should be getting it. It brings us onto our final quick hits, which is what of each of our podcast members taken away from this paper. Max, would you like us to start us with your first quick hit? Yeah, thanks, Pash. I mean, I think this paper for me really helps to reframe traumatic cardiac arrest in terms of indications for thoracotomy for me, just away from, uh, I guess the mindset of blunt versus penetrating into trying to understand what is the underlying pathology, you know, is this tamponade,

exsanguinate and, and the vastly different outcomes, uh, those two patient groups have got. So yeah, that's what I take from this. Thanks. I think I'm not massively different, max. I think it's, uh, and it comes down to simple stuff, doesn't it? It's, um, get the diagnosis, work out what the pathology is, and treat that pathology with whatever therapy is best, whether that is blood, whether that is thoracotomy, whether that is, um, decompression of, uh, of attention. Hemothorax. I think for me, what I've taken away is in getting the diagnosis and ultrasound can't be very useful, especially assessing tamponade. But, um, it shouldn't be any cause of delay of care. And so to use as you can, but not to delay the care going forward. For me, um, I think it really, really drove home how time critical these conditions are. And what

we've been training our, um, our registrars and, and conditions is to be very clear in their heads as to what is traumatic cardiac arrest. So that. When the patient is in traumatic cardiac arrest, they can start the intervention. If, if they think it's from tamponade, is that they start as soon as possible because waiting five minutes to be sure results in, in quite poor outcomes. So trying to get if it's indicated, trying to have it done as early as as soon as possible, and then also separately shaving off that tail of futile um, procedures. So that brings us to the end of our second episode, a general review episode, and all that's left to say is thank you very much to Mr. Zane Perkins, the lead author for giving up his time, uh, Mr. Chris Elwin, max Marsden, and Rasheen Kelly, et. For tuning in from all across the world. Uh,

currently 6:00 AM in rasheen's time. Mr. Chris Elwin co-leads the MSE in trauma sciences, the er, university of London. And if you want to expand or stay on top of your major trauma research, uh, it's a great place to go and learn. Uh, we're looking forward to rejoining you in a few months time for our next case for review in trauma surgery. But until then, all that's left to say is. To our US listeners dominate the D and to our UK listeners, Cheerio.