Podcast – July 2024 Round-Up

Welcome to the St. Emlyn’s podcast. I’m Iain Beardsell.

And I’m Simon Carley

And believe it or not, Simon, this is our podcast blog update for July 2024. Now, this does give away the fact that both you and I have had pretty busy summers, and we’re just sorta getting back into our St. Emlyn’s term time activity. How have you been?

Oh, really good, actually. I had a really nice time out in Malaysia, doing the MRCEM OSCEs, a bit of a fly out there and fly straight back. So, I only saw a little bit of Malaysia, but what a wonderful country, what wonderful people, and some fantastic candidates. It was a lovely, lovely place to go and a joy to examine.

And there are lots of exciting times coming up for both of us, actually. I’m flying today to Sweden to go to Tactical Trauma 24. I was looking at the faculty list for that conference. We’re going to go and talk to some of the speakers. Myself and Liz Crowe are bringing some interviews from those. Some other highlights—the speaking list is incredible. People with jobs that, frankly, I couldn’t make up if I was writing an action novel. So, I’m really thrilled to be going. Can’t wait to catch up with Liz again. It’s all too infrequent that we get to see her, but lots of content coming your way. And I know, Simon, you’ll be busy at the scientific conference next week.

Yeah, so we’re looking forward to catching up with friends and colleagues up there in Gateshead. Always a fantastic place to go. Really lots of fun. And yeah, it’ll be great to catch up. And again, the programme for that looks fantastic, actually.

Shall we get straight on to some blog content and talk about some emergency medicine critical care?

Indeed, let’s go back to July.

The first place we’re going to talk about, Simon, is one that’s, I’m sure, very close to your heart, although not written by your team in Manchester. This is a systematic review of the Manchester Acute Coronary Score, the MACs rule. Perhaps you could give us a bit of a background on MAX and then a little bit about this paper because it may not be familiar to everybody.

The Manchester Acute Coronary Score is a whole suite of actual scores, which we use to basically risk-stratify patients who come into the emergency department with chest pain. Essentially, what it does is it takes clinical characteristics of things like the nature of the chest pain, where the chest pain is, whether sweating is observed—things like that, which you’re seeing in a lot of other scores. When it combines it either with biochemical markers like the T-MAX or the H-T-MAX, where you’re just using sort of clinical features. And on the basis of that, we have done extensive work—when I say “we,” I mean Rick Body and colleagues—on working out what the sensitivity and the specificity of those scores are.

Now obviously, we’ve developed it in the cohort of patients who exist here in Manchester, but that’s a derivation cohort. You only know whether a score works if it’s been validated elsewhere. So what this study does—and we weren’t involved in this study, it’s nice that somebody else has chosen to do it—is go out and look at all the studies which have examined whether the MAC scores, the suite of MAS scores, work, and worked out which one is best. They’ve also compared it against some of the other scores that are out there.

The summary was, it’s the MAC models—the T-MAC, the one that uses troponins—that got the highest overall accuracy, with a sensitivity of 96% and a specificity of 36%, according to the initial findings. You might think the specificity is pretty low there, but that’s okay, because what it basically allows you to do is to take that group of patients and then skim off the ones that almost certainly don’t have a significant coronary event. They can go home or have something else done as outpatients, and then you can focus on the ones who remain.

And the other thing T-MAC does, which is very clever, I think, is it gives you an actual probability of whether or not somebody is actually having an ACS. So depending on the score, it’ll come back and say something like, “Oh, this person’s got like a 4% risk; retest them in six hours, and then if that one’s okay, you can send them home.” Or it might come back and say, “This person’s got a 30% risk,” in which case, give them a load of drugs like antiplatelet drugs and refer them to cardiology. You can nuance this, and it can actually guide the next stage of the process. It’s not just diagnosing the condition; it’s also driving care and driving referral, and that’s actually incredibly useful.

Regular listeners to the podcast will remember our last episode about the SHED study with Dan and Tom, where we talked for a significant amount of time about pre-test and post-test probabilities, the use of sensitivity and specificity, and likelihood ratios. There’s something very similar here about what we actually do as doctors. We take our pre-test probability, we apply a test, and we get a post-test probability. The MAX score reminds me a little bit of the Canadian Subarachnoid Rule in that it’s very sensitive, so it’s good for ruling out. It’s not very specific, so it doesn’t help you rule in. We have lots of tests in emergency medicine that are like that. But as I was saying to our group of fourth-year medical students yesterday, often our job is to tell people what they don’t have. We’re not telling people what they do have. And perhaps the MAX rule will be a good one. Are you actually using this in Manchester?

Yeah, so if you come in with chest pain, we’ve got an EPR (electronic patient record), an Electronic patient record, which I frankly hate, but we’ll move on from that for now. But on that, if you go to a patient with chest pain, you can download the protocol, which is linked into the EPR. You click on all the various factors, input the troponin, and it tells you what the score is and what to do with the patient. So, yeah. And also, you say it doesn’t rule in, but with the higher-probability patients, what it does do is rule that patient into a referral to subspecialist cardiology, as opposed to just continuing in the observation unit.

That’s a really interesting point, I guess, that it rules into a different investigation pathway, rather than ruling in the disease. That’s a good thought. I haven’t really talked about that before, but I can see how that would be useful.

And as you know, the next blog post does relate a little bit—we talk a lot about hearts and chest pain, don’t we?—but this was the podcast with Steve Smith, which I do hope people have had a chance to listen to. It was a real joy to be able to get Steve onto the podcast and talk to him a bit about his work with occlusive myocardial infarction and, more specifically, the use of artificial intelligence to look at ECGs. This is something I am very keen for us to think about doing. AI is undoubtedly going to be a big part of our futures, and I would encourage you to listen to that podcast.

The things I really took from there are—well, I have a lot to learn about occlusive myocardial infarction, and I think we all have to try and work out whether we rid ourselves of these old-fashioned ST-elevation/non-ST-elevation diagnoses. That’s something to think about, I believe. But also, where is the place for this app—this ability to analyze ECGs in the emergency department? I’m particularly keen that we might try and get it into what we call our pit stop area. You might have a rapid assessment area, the place where everybody seems to end up before they go to our majors area, and it strikes me that almost every patient gets an ECG these days. We’re almost regardless of presenting complaint, and then that ECG is thrust in front of a clinician. And I have to admit that the knock-on effects of those interruptions, I think, are as yet unqualified, but are significant.

So I would recommend that you go and have a listen to that, and there is an extensive blog post there, and you can try out the app. We have no financial interest in the app whatsoever, so please don’t think we’re promoting it because of any other reason than that I think it’s a good thing. And there are links on the blog post, so you can try it out, have a few free goes, and see how it works for you. But I think there may be a future in this, and I know that myself and Rick are very interested in looking at this as a research project going forward.

Yeah, I thought this was a fascinating podcast. It took me back some time ago, and I discovered—do you know why the leads are placed on the chest in the places they are, from V1 to V6? It’s completely unevidence-based. It was a consensus document in the 1930s between the American Heart Association and the British Cardiac Society, because up to that point, people had been placing them all over the chest. And they said, “Well, let’s put them here,” and that consensus document has remained ever since. You’ll know the heart’s got a front and a back. So, it’s quite good at looking at vessels at the front—your right coronary, your left main stem, and your left anterior descending. But for things like the circumflex and obtuse marginal arteries at the back, or right ventricular infarcts, it’s really not a very good system at all. And what this AI thing does is it takes the 12-lead ECG, and it can look for essentially reciprocal changes and all kinds of subtle things that are missed because we’ve got the leads in the wrong place. And it gives you this diagnosis of an occlusive myocardial infarction (OMI), which I really love because it makes you sound cleverer than you really are when you start talking to cardiologists about an OMI versus an ST-elevation infarct.

So, there are a lot of wins here. It makes you cleverer, makes you look cleverer, and it actually helps patients. What a great podcast. Go and have a listen.

The next blog post from this month’s content is about non-fatal strangulation. This seems to be a topic that’s becoming more prominent. There have certainly been some documents released recently, and this guideline is one that you’ve discussed in the blog post. This is about having an awareness of people who come in with things that haven’t killed them, but clearly, we need to think about taking action to protect them further.

Yeah, so it’s from the Faculty of Forensic and Legal Medicine, but it’s done in conjunction with a whole bunch of other organizations, including RKM. We probably see quite a few patients with non-fatal strangulation. It’s almost certainly underdiagnosed in healthcare, particularly in emergency medicine. But actually, there are huge consequences from it. There are the medical consequences, for instance. A number of these patients may end up with very significant injuries, notably carotid artery dissection. So, if there’s any suspicion that they’ve had a significant non-fatal strangulation, the document suggests that contrast angiography of the neck vessels is advised, and I think that’s really good clinical advice because we really don’t want to miss that. And then there’s a whole bunch of stuff here about safeguarding, about making sure that these people are going to have good follow-up, dealing with the domestic violence issues, making the appropriate referrals, working with the patient to get consent—all those things are so incredibly important. Because there’s no doubt that the patient who presents to you today with a non-fatal strangulation is at significant risk of being murdered. We do a lot of prevention in medicine—just think of taking a troponin and doing secondary prevention for myocardial disease. How important is it to do the same sort of thing and try to prevent an awful event later on?

So, it’s a really good read. It’s a nice guideline—it’s not too long. Definitely something you should be disseminating in your emergency departments and in pre-hospital care.

The interface here between the ED and the police, I find, is very challenging. It’s difficult to know when you can tell the police about what’s gone on. As far as I read it, it’s not a statutory reporting thing in the same way that knife injuries are. So, you cannot tell the police without the patient’s consent. There are a lot of ethical things to think about, which the guideline does touch on. But it is an important thing to try and think about. And of course, a lot of these patients are scared, frightened, worried, and don’t want you to involve anybody else. Part of our job is to try and help guide them to the next best thing that they can do to protect themselves. But it’s never easy.

It’s not. But as I say, you could potentially make an enormous difference here. And as you said, they may be scared, and they may actually be reluctant to admit what’s happened.

The next blog post is about our old friend, REBOA. It keeps coming. It keeps going. Maybe it’s one of those things we’re always desperate for—the next thing where we can actually make a difference and feel like we’re doing new stuff. I always think of emergency medicine as doing a lot of regular stuff really well. But like surgeons who get a fancy new robot, we love new technology. And REBOA strikes me as one of those. This is a post from Hutch, who’s new to the podcast, and it’s really nice to have him along to talk about pre-hospital REBOA and whether it’s useful in exsanguinating sub-diaphragmatic hemorrhage. Where did you get to with this one? I know Zaf’s talked about it on the blog before.

Yeah, so coming back to REBOA—gosh, that’s awful. We had the UK REBOA trial, which was the use of REBOA in severe hemorrhage. But that was a randomized controlled trial that looked at REBOA use in the emergency departments. We won’t go into it too much now, but it was done too late in the wrong sort of patients, and it didn’t work. So, it’s not that REBOA is dead; it’s that, you know, if you do it in the wrong patients at the wrong time, it doesn’t work. No great surprise there.

This is different. This is moving REBOA much further forward—into the pre-hospital phase—and it’s for those patients who are basically just dying in front of you. These patients haven’t got a lot to lose because they’re almost dead anyway. So they took—this is almost a feasibility study here. The other thing that’s changed is that this is a partial REBOA catheter. The old REBOA catheter was either basically on or off. The characteristics of it, which I won’t go into now, are that when you put up an old-style REBOA catheter into the aorta to block flow, it’s either blocked or it’s not blocked. You might think, “Oh, I’ll just take it down a little bit to allow a bit of flow past.” It didn’t work that way—it was either on or off.

The new catheter allows some flow below the balloon, so it’s potentially kinder to the rest of the body and makes a lot more sense. In this paper, what they did is they took 16 patients who were essentially dying of exsanguinating hemorrhage. Fourteen of them were already in traumatic cardiac arrest. They put the partial REBOA in, blew it up, and they got an immediate change in blood pressure. Of those patients, two survived—so an 18% survival rate, which is pretty amazing, actually, though it’s small numbers, and you have to be very careful about that. It’s a very highly trained team—they’re very slick with this, whereas most people won’t be.

The other thing about this is, what is partial REBOA doing? A lot of people will think it’s stopping blood from coming out wherever the holes are below the diaphragm. But I think the data now is suggesting that what partial REBOA does is it resuscitates the heart. We’ve seen this in some of the early cardiac arrest studies as well. What you do is you put the balloon up in the aorta, it increases end-diastolic filling pressure from the aorta into the coronary vessels, and it basically resuscitates the heart. These patients are dying essentially of heart failure, aren’t they? There’s no blood flow into the heart because they’re exsanguinated and the heart fails. If you can reperfuse the heart, then you’ve got a chance. So, it’s not just that REBOA is changing in terms of what we’re doing it for or where we’re putting it, but our understanding of what it’s actually doing is changing as well. It’s not about stopping the bleeding; it’s about resuscitating the heart, perhaps. Who knows? But this is really interesting. Go and have a read.

Maybe, Simon, before both you and I retire, this will be a standard treatment. Or maybe it’ll go the way of the mast inflatable suit thing that we started talking about for external hemorrhage when I was a boy, and it will go into the bin of interesting things we never did. But we’ll find out, and I’m sure people will keep investigating it.

Throughout the last couple of months, we’ve been really lucky to have podcasts from the Premier Conference, where the organizers—Clarissa Chase, in particular—allowed us to take live recordings from this conference that happens in Winchester. It’s aimed at pediatric emergency medicine. We’ve been able to edit those down and publish them on the podcast and blog, with some extensive notes if you’re interested in them. If you have any interest in pediatric emergency medicine, I’d highly recommend them.

In July, we had podcasts about eating disorders, which I think are massively under-recognized and perhaps don’t necessarily get the attention they should. I would highly recommend you have a listen to that. It will really reframe how you think about these patients and, crucially, how you talk to them. As we all know, what we say can be incredibly powerful or incredibly destructive, and with these young people, it’s really important to be so, so careful.

Yeah, I thought it was a really great podcast. We’ve done some stuff around eating disorders in the past on the blog, back to when the guidelines used to be called the Marzipan guidelines—thankfully, that name has changed. But there’s really cracking stuff in here about looking for key red flags, like rapid weight loss, heart rate and blood pressure issues. Bradycardia is really bad. Postural hypotension is really bad. And muscle function—so the sit-squat-stand test, the SUS test, which we’ve talked about before. I think this is absolutely essential.

There’s also stuff around diabulimia, which is in the press at the moment because of some major problems in the UK. This is where young diabetic patients intentionally go into ketosis to lose weight. The other thing is, I keep telling people this—of all the mental health disorders, anorexia has the highest mortality rate. This is really serious stuff, and we definitely see it in emergency medicine. We definitely probably don’t handle it as well as we could. So, please, please do some work here.

And you mentioned diabetes. One of our next podcasts was from a colleague of mine at Southampton, Nicola Trevelyan. This is about hybrid closed-loop insulin pumps. I didn’t actually realize, until I went to this talk, that these are now the recommended treatments by NICE in the UK—that all type 1 diabetes patients should be having these fancy gadgets, hybrid closed-loop pumps, which simultaneously measure their blood glucose and give them the right amount of insulin, and really are pancreas replacements. We’re going to have to get better at knowing these technologies. For people like you and me, Simon, this wasn’t anything that happened when I was at medical school. It wasn’t even around when I was training, so we have to go back and understand a bit about it.

Now, often it will be younger patients who have these because they’re perhaps more motivated to get their glucose control sorted out, and maybe we concentrate on giving newer technologies to our tech-savvy younger people. But there are a few very simple things that Nicola goes through in the podcast, through some case presentations, where if you know a little bit, you can help a lot. These gadgets, if you don’t deal with them properly—a little bit like cardiac pacemakers—if you don’t know what’s going on, then you can cause real harm. Actually, just listening to this 10–15-minute podcast will really help with your understanding.

Yeah, I thought it was really good. There are a couple of takeaways that I took from this one. Most of the problems that you’ll see with somebody who’s got a pump are actually relatively simple to sort out. So, it’s a pump with a cannula—it could be blocked, so that’s going to cause a problem, isn’t it? But spotting that would be fairly easy. You might see a kid who comes in and everything is fine, but the continuous glucose monitor, which they wear, is reading high and everything seems okay. But you look at it and the cannula is actually not working, so they’re just not getting the insulin—that’s fairly easy to sort out. You can see the ones who’ve been unwell, or the machine’s just basically failed—that’s possible, but probably less likely. Or they’re just not eating enough, and they go into starvation ketosis. You can see those problems. Those are the three big things.

The other thing, which I don’t think is mentioned too much in the podcast, but came to me because one of my medical students who’s diabetic told me about it, is that people hack the pumps. So, you can actually hack the software in your own pump and change it to what you want it to be. There’s a whole bunch of really tech-savvy kids out there who are going online and looking up how they feel they can hack their pumps to make them better, which I think is absolutely insane. I mean, it’s really interesting that people are taking control of their healthcare, but I’m not entirely sure it’s always going to work out brilliantly.

And I guess that relates back to what we were just talking about with the eating disorders—if you want to change your endocrine makeup to aid with weight loss, that would be one way of doing it. Honestly, trying to keep up with younger people and all this stuff is almost impossible, isn’t it? But we can try, Simon. We can try.

Yeah, really interesting stuff. And it’s so much better. If you look at the HbA1c levels of these patients who are on the pumps, they’re approaching, if not absolutely normal. It’s transformative technology. Really, really good.

Lidocaine or lignocaine patches, Simon—I’ve been slapping these on people for a while and never quite sure whether they work. I think it sometimes treats the doctor or clinician more than it treats the patient. It feels like a low-impact kind of intervention with low toxicity. This is talking about a feasibility study that you reviewed, about lidocaine patches for elderly patients with rib fractures. Is this something we should be doing?

Well, we don’t know. I think your summary is pretty good there. We don’t know. I use them as well on the major trauma ward, often for the elderly patients who aren’t really suitable for fixation. They may or may not have had a block put in, but maybe the block’s worn off. It’s a few days down the line, and we don’t particularly want to give our elderly patients large doses of NSAIDs because of the problems with kidneys, gastric ulceration, etc. So, we stack them up on a bit of opiate and paracetamol, and they’re still in pain. You put these lidocaine patches on, and sometimes it seems to work, and sometimes it doesn’t. I don’t know. I do use them, and I would like to know more.

This feasibility study, I hope, is going to turn into a randomized control trial. In this study, there were 100 patients—48 got the lidocaine patches, 52 got standard care. You can’t really placebo a lidocaine patch very easily. They looked at pulmonary complications, and the rate of pulmonary complications in this group is really high. That reflects my experience on the ward as well. 53% of them had significant pulmonary complications, so I think we’re going to see an RCT out of this, I hope. In the meantime, I think lidocaine patches are interesting. You can give intravenous lidocaine for chronic pain, so I’m always intrigued when you put this patch on the outside of the skin, and it’s got three fascial layers, a bunch of muscle, and a load of other stuff between it and the fracture—whether or not the local anesthetic actually makes any difference. I do wonder if you put it on your leg, would it make any difference? So, maybe that’s another RCT. But I just don’t know. I’d want to know more. I think it could be good.

For all the things we do, sometimes we just want to do anything that might help and not cause harm, don’t we? And this has always fallen into that category for me. And I suppose if I’m not paying for it, and I’m not asking the patient to pay for it, I should be more mindful perhaps of the NHS budget. But little harm, some benefit potentially—I tend to try it. But I don’t think they’re the panacea we would like them to be. They do, as you say, give us this great idea of an intervention, but when you think about the physiology, you do wonder a little bit.

Of course, with all the trials, we talk about all the papers, all the references you can find on the blog site. We would always encourage you to go back and read the papers yourself. Please don’t just believe us—definitely don’t believe me. I tend to believe Simon, but go and read it for yourself. That paper’s in the Emergency Medicine Journal, one of our all-time favorite journals for all things emergency medicine.

So, Simon, coming to the end of July, there’s still a couple of things to chat through. One was what we call a critical appraisal nugget, and it’s delightful to have Rick back doing these occasionally, talking about statistics. There’s something about medical statistics, isn’t there? As soon as you call it that, it becomes a bit of a dread subject. Just yesterday, I was talking to some medical students, and we were talking about likelihood ratios—a subject I’m really disappointed they had had zero teaching on. In the feedback at the end—these are fourth-year students, so they’ve done quite a bit of medicine—it said, “Really interesting new concept.” We were chatting about pre-test probabilities, which I bang on about, but learning a little bit about medical statistics and understanding the tests we use.

Here, this is about positive and negative predictive values and how they differ from sensitivity and specificity, and how we can use them. I think it’s really important, and I’m encouraging Rick and the team with Greg Yates to do some more of these because I think the more we understand the tests we use, the better clinicians we can be.

I think you’re really good. We’re going to do some more of them. Particularly if you’re heading up toward exams or critical appraisal, I’d strongly recommend listening to these in the car. We’ve also got the book on the site about understanding risk and probability in emergency medicine, which, if you’re interested in diagnostic statistics, goes into a bit more depth on that. It’s been quite a good read and had loads of downloads, so it’s quite fun. But yeah, it’s a key thing, isn’t it? If you’re going to use diagnostic tests, you really should understand how they work.

The thing I got from the session I did yesterday was that nothing in medicine is really black and white. We seem to teach everything in a binary way: they have this, or they don’t have this. We have treated this disease because they have it, and we’ve ruled this disease out because they don’t. As soon as I got into this with the student groups I was talking to, it was like I’d revealed some unbelievable truth that, actually, it’s all a shade of gray. And I do sometimes use your word, “probabilistician.” If I ever write it down, my spell check doesn’t like it. But that’s what we do—we’re in the world of probability. It’s more likely you have this disease. Now, we have to weigh up the harm and benefit of treating you for it or not treating you for it. I think that’s where medicine is heading.

I think if I could encourage everybody to increase the flow through their emergency department, it would involve them understanding their diagnostic testing a bit better and using their diagnostic tests in a rational fashion so they can make really informed decisions. Because sometimes, those decisions don’t have to involve extensive testing, whether it’s cross-sectional imaging or ongoing blood tests. And often, clinician gestalt—dare I say it—is as good as any of these diagnostic tests.

Have a look at these. There’s a whole series of critical appraisal nuggets that you can go back and relisten to, and they may open your eyes to things. And as I say, have a look at the book we’ve published on St. Emlyn’s about risk and probability because it may be something new to you but could change your practice significantly.

The last post for July is another podcast from the Premier Conference, and this is about button battery ingestion—again, a topic we’ve covered on the blog site before, but an important reminder. This is from Francesca Stedman, who’s a pediatric surgeon down in Southampton, talking about what we need to do for these patients, who are often very young, and often we have to have a high level of suspicion. These batteries exist in all sorts of items, so making sure you’ve thought about this and going down the line of, “If you think they’ve swallowed one, we need to check it out,” because it can be so, so dangerous. There are little bits in here I didn’t know about, like the different types of batteries and how they cause burns and what you need to do, and how quickly. But it’s really worth a listen. Again, all of these are quite short talks that won’t take much of your time—probably half of your commute into work—and will really aid your learning.

I had a recent case, actually—in the last couple of years—where a child had a button battery stuck up their nose. We often think about ingestion, esophageal perforation, and the patient dying. But actually, just stuck up the nose, and the patient was brought in. While I was thinking about whether or not we needed to sedate the child to get the button battery out, one of my colleagues just went in there and took it out right away. It hadn’t been in for very long, but you could already see the burn within the nose. It was really quite dramatic. The speed at which these things can cause damage is remarkable. It’s a true surgical emergency.

You may need to get others involved, and depending on the center you work in, that might involve a pediatric surgeon. Although, to be honest, they’re so busy these days—all of our inpatient colleagues seem to be working all hours of the day. So, the idea that we’re getting people out of bed is probably outdated, but this is the time to get this patient to the front of the queue, do the investigations needed, and involve the specialist.

Simon, that is July. It feels like a long time ago. We’ve had summer since we wrote some of those posts. We’ve had a test series. We’ve had some sunshine. But some good content there, I think.

Absolutely. Do enjoy the academic conference next week.

I cannot wait to be with the guys in Sweden. I think it’s going to be brilliant, and I think I’m going to learn a lot. There’s not much chance I’ll be involved in providing medical care in a war zone or up a mountain, but sometimes, just learning about what other people do can really enhance your own understanding. I think crazy things can happen in Hampshire—you never know.

Simon, take care, and we’ll speak soon.