Podcast – Intro to EM – Chest Pain

Welcome to the St. Emlyn’s podcast. I’m Iain Beardsell, and I’m Simon Carley. And today, in this induction podcast, we’re going to tackle that very frequent presenting complaint to the emergency department, and one that vexes us all, no matter how senior or junior you are: the patient who presents with chest pain. So Simon, let’s get straight into this, no messing about. The patient turns up with chest pain, what are your first priorities?

So, chest pain, it’s a really common presentation to the emergency department. So you’re going to see loads of this when you’re working with us. You’re going to see loads of different sorts of patients who come in, some of whom we’ve got serious disease, but they’re actually relatively infrequent, and many patients who don’t have particularly serious disease. The problem is, is that those difficult diagnoses, things like acute coronary syndrome, pulmonary embolus, they’re actually quite serious. So amongst this great mass of patients who you’re going to see, there are a number who you really don’t want to miss, and they can be quite tricky.

So we’ve got a top five, as ever, with our induction podcast, set of diagnoses that we’d be want to rule out, and always remember that emergency medicine, we start at the back and rule out the bad stuff first. So my top five I tend to think of, as you say, acute coronary syndrome, P.E. I include pneumothorax in there, pneumonia, and that bane of the emergency physician’s life, aortic dissection. They’re the five I tend to think of. Does that seem like a reasonable list of rule outs in the patient with chest pain?

I think those are the big ones that you do not want to miss. Those are the ones that you’d like to spot while my first presentation to the emergency department, to tell the patient that they either have or have not got it, and to really manage those patients well. So if we start and take those in order, we’ve done quite a lot on the St. Emelene’s podcast about ACS, albeit really focusing on troponin. When we’re looking at a patient and trying to decide if they have an acute coronary syndrome, what are the important questions to ask them?

Well, I think you’ll get a clue, really, from when the patient arrives and gets triaged. If you’re using something like the Manchester triar system or any of the other common triar systems, there’ll be characteristics that the patient will tell you that will move you towards one diagnosis or another. So some of those things that you mentioned, like the pneumothorax, the PE, characteristics of pain, which are respirophaisic, so they change with respiration, may push you towards one side. Patients who have characteristic symptoms of central crushing chest pain or radiation to the arm or neck, that might push you towards more cardiac. The difficulty is, of course, is that not all patients have read the textbook, and some patients with a PE might present with characteristics that would normally be felt to be associated with acute coronary syndrome. So it’s a bit tricky. You get some clues when the patient first comes through the door and you’ll have some standard investigations that you do pretty much for everybody. Pretty much everybody’s going to get an ECG when they first come in. Would you agree?

I think you’re right. An ECG is a vital investigation, and one that every emergency physician has to be an expert at interpreting. At first, we’re just looking for those really obvious changes, but we need to also be good at finding the subtle things too, and we will direct you to some of the excellent ECG websites, podcasts, and blogs that are out there on the net in the show notes. I think you’re right. The ECG can be very, very helpful. Steve Smith does a fantastic blog on this, doesn’t he? In our department, the only people who are allowed to read those first ECGs are senior emergency physicians because we’ve had so many missed, and I think that’s partly because when you first come into emergency medicine, you may have seen classical ECGs a lot of the time, but there are so many subtleties there. And just while we’re on ECGs, I’m not sure how you feel about this, but often when you see an abnormality on an ECG, the request is, “Can I have old ECGs please?” And then this hunt goes on to find old ECGs so that we can reassure ourselves that comparing with things that have happened in the past makes everything okay. I would try and implore people to take every ECG on face value because let’s remember that even if you had changes in the past, you could have been having an episode then. So just because the changes are the same doesn’t necessarily mean that that’s okay.

Now, I’d agree with that entirely, and similarly, you get an ECG given to you and somebody will say, “Can this person go to the waiting room?” Well, I don’t know because it’s an ECG; it’s only part of the assessment, and a rapid assessment of the patient is almost always essential to make a decision. So we’ve got this patient who’s turned up, they’ve had an ECG that may help us direct them a little bit as to whether we can rule in a disease, but we’re nowhere near ruling anything out yet.

So the patient with ACS, obviously there’s a history and examination findings we were taught at medical school: a sweaty, clammy, middle-aged man looking a bit like me after I’ve sort of gone on a brisk walk, clutching at his chest and feeling unwell. What other questions are important? Well, it’s interesting, one of the things that you didn’t mention there of course was previous risk factors because there’s actually quite a lot of evidence out there now that previous risk factors, so things like smoking, hypertension, diabetes, don’t affect your ability to diagnose an acute coronary event in the emergency department. Now, there’s a whole other podcast on why that is, you just have to take it from me, it doesn’t count. You have to take the patients on what their symptoms and signs are on the day that you meet them. So talk to them, examine them, what are the characteristics of the pain? Is there anything here to suggest that this is pain which is compatible with myocardial disease? And I like that phrase, it’s not this, “It sounds like a myocardial infarction,” it’s “Could this person’s symptomatology be compatible with a myocardial cause?” Because if it is, even if it’s a bit vague, even if it’s a bit strange, not quite right, maybe they’re a bit too young for what you think might be the right age group, then you should go forward and investigate them. And the way things are now, I don’t think there is an appropriate age range for people having myocardial ischemia, so we’re seeing younger and younger people having these events.

So we’ve got the patient in front of us who we’re trying to rule out an ACS, do all these patients need a troponin or a high sensitivity troponin? I think if you’ve raised the question that myocardial disease or myocardial ischemia is a possibility, the answer is yes, it’s relatively straightforward to do. It does mean that you’re going to investigate more patients than you find disease in and in our department, if you’ve got a normal ECG, about 10% of the patients who investigate will have disease. It feels like a low number, but that’s actually quite a lot of patients who come through the department. So if you’re worried about this person having an acute coronary syndrome, you must investigate. And that would include a high sensitivity or standard troponin test. And of course, we’ve done plenty of this on the St. Emelon’s blog and podcast. And please do go back and listen to those.

So we’ve got ACS as an idea. We need to make sure we’re ruling that out. Now, the other thing that then spooks most emergency physicians, I think, is pulmonary embolus. How would you go about approaching ruling out pulmonary embolus in this patient who’s presented with chest pain?

The classics for pulmonary embolus are, again, that resparophasic chest pain. So pleuritic type chest pain, as some people would call it. It’s a classical history which many people don’t have, so it can present as shortness of breath, it can present as somebody who has respiratory difficulty, but with associated risk factors of recent immobilization, cancer, surgery, etc. So you make a judgment about whether or not this person has pain which is compatible with pulmonary embolus. And if it is, you’re going to go through a standardized investigation protocol, which in our department involves well-scoring and then D-dimers for low-risk patients or well-scoring if they come out as high risk, then we automatically investigate them with either CTPA or VQ scans. You’re making a decision about whether this person could have PE, but we seem to investigate an awful lot of people for PE. And one of the most important questions at the beginning is, do you really think this person is having a PE? Because if you do investigate them, but if you’re not sure, you could potentially put them on a pathway of numerous investigations, return to hospital, more radiation in terms of CTPAs. And you need to be very careful that you don’t want to take that first step unless there’s good reason. So I would advocate, particularly when you first start an emergency medicine, always going and having a chat to a more senior emergency physician and asking them, “Do I really need to investigate this person for PE or is the fact that they’re 28 years old, playing rugby at the weekend and got smashed in the ribs a more likely cause?” And I have one objective criteria that I tend to use, which I find useful and you thought you didn’t mention. I’ll be interested in your thoughts on the PERC rule, which I’ve started using more frequently now.

Jeff Klein, I think, is the expert on pulmonary embolus in the emergency department. PERC was one of his things

that he used as a decision-making rule. And I really use it in those patients in whom I don’t believe they have pulmonary embolus to give myself an objective score to reassure myself. Is that a reasonable way forward?

Yeah, absolutely. I mean, I use the PERC rule as well, but the starting point of the PERC rule is an experienced emergency physician thinks that pulmonary embolus is unlikely. So unless you are an experienced emergency physician, you probably shouldn’t be using the PERC rule. You can use it and say, “Well, actually, I think it is,” but then go and speak to somebody who does have that background, that clinical judgment in those years of experience who can make that decision not to investigate. And I use PERC in those circumstances when I truly believe the patient is incredibly low risk. I use it to convince myself and more importantly, convince others that the D-dimer is not necessary. We’re then able to stop investigation because we will always have that patient with a D-dimer, which of course is a sensitive but not specific test who come out with the false positives and then are destined for that unnecessary investigation. So I do find PERC useful and like yourself, I use a combination of PERC, well-scoring, D-dimers, but really in my experience, the patient who’s got the pulmonary embolus is often relatively straightforward. They have been in a mobilisation, they have got active malignancy. The history is there to help you and in this case those risk factors do matter. So having had those things that predispose to clot are very important questions to ask and really any of those patients I’m going to think very hard about before trying to rule out pulmonary embolus.

I would agree with that entirely and I think the other great thing about the PERC rule is it does give you something to write in the notes to justify that you did make a formal assessment. So from a medico-legal point of view, it’s actually quite helpful as well.

So we’ve thought there about ACS and PE. We did mention a couple of other diagnoses. I always include trying to rule out pneumothorax in these patients who present with chest pain and in this I’m including both the younger patient who’s presenting and also the older patient perhaps with preexisting respiratory disease who’s presented with pleuritic type chest pain. Well, I think for all of these patients, I have a very low threshold for getting a chest x-ray in any patient who turns up with atraumatic chest pain. I have a fairly low threshold for getting a chest x-ray in people who turn up with traumatic chest pain as well, come to think of it. But the exposure to radiation from a straightforward, departmental chest x-ray is incredibly low. And although the diagnostic yield can be relatively small, the risks are incredibly small. So I would get an x-ray in most of these patients and that will tell you whether you’ve got a pneumothorax most of the time. It will tell you if you’ve got a significant pneumonia and you’ll find some other associated features, I hope, such as cough, sputum, temperature, etc. Dodgy one. The yield for the last mentioned, which of course is the ill-ticked essential.

Pneumothorax, relatively straightforward. Chest x-ray should rule in and rule out as these. It’s a relatively sensitive and specific test. Pneumonia, we’re going to find those other symptomatology. It’d be rare to have consolidation, I think, without some form of fever, some cough, coughing something up. It’s pretty obvious that the patient’s got an infection. But then we do have this final one which I guess we should touch on, which frightens all of us. How do you investigate these patients where we’ve thought about ACS but it’s that history of pain in the chest going through to the back, that pain between the shoulder blades that we all remember from the Oxford Handbook as being pathognomonic almost of aortic dissection. How do you go about reassuring yourself that all of these patients don’t have that without seating everybody who walks through the door?

Well clearly you can’t do that because the radiation dose would be huge. I think it’s tricky. I was speaking to some of my cardiac anaesthetist friends recently and they’re saying that they do see the aortic dissection and it’s surprising how many of them are not picked up on day one. They’re not infrequently picked up on day two or day three of a hospital stay for patients who’ve been admitted for other causes. And I think there’s something inevitable that will happen. However, the ones I picked up in ED picked up a number and it’s usually because the pain is in excess of what I would expect. It’s a severe pain as you describe that classical feature going through to the back but it’s more than you would expect from other causes of chest pain that we see in the ED. You may see things on the chest x-ray but to be honest it’s often quite rare. I picked up a few on ultrasound doing echoes in the ED where they’ve dissected all the way down into the abdominal aorta but it’s quite a difficult diagnosis to make. The bottom line is if you see a patient who’s got severe symptoms and it just doesn’t kind of make sense, go and speak to somebody and consider it as a diagnosis. Almost have that mental checklist that hang on a minute could this be? I’m going to go get some advice and have a think about it. And I think with aortic dissection as soon as the question enters your mind if you cannot get rid of that nagging thought that it could be aortic dissection you’re almost on a bound to get further investigations. And I think the only real investigation that can rule in and rule out this disease is a CTA autogram. I don’t believe that a normal chest x-ray rules it out sufficiently if the symptomatology has suggested it and examining the patient has brought that query into your mind.

Absolutely. There was an interesting study actually which we did on the St. Emelene’s blog looking at triple phase or triple type scans, CT scans of the chest for these patients to pick up coronary artery disease, to pick up PE and pick up aortic dissection. And whilst they could demonstrate that they could pick up the aortic dissection the numbers were so incredibly small that it wasn’t worth doing it for everybody. So you do have to do that selection but if you genuinely feel that it’s a problem if the patient has the signs and the symptoms which make you worried that don’t fit into the pigeonhole of the diagnosis you want them to have then do consider the diagnosis and yes a CTA autogram these days it’s not difficult to get in a major centre and it will rule in and rule out your diagnosis.

So there we are really, that’s the top five life threatening worrying causes of chest pain that present to us in the emergency department. Of course there are others, it’s probably worth us just reiterating what we’ve talked about there. So the top five that we consider and this is all reiterated on the CEMET video that you can go off and watch which we put onto the blog post. But the top five are acute coronary syndrome, pulmonary embolus, pneumothorax, pneumonia and then aortic dissection. And anytime you see a patient with chest pain our aim is to rule out those diagnoses. We’re always working backwards. So take the worst things it could be and make sure that you and the patient both know that they haven’t got those illnesses. And then you come down to the patient having something else. So I mean I guess we should think just a little bit you’ve ruled out all five of those. The patient still has chest pain. They want to be told what’s wrong with them. What do you do to explain to them when you just really you don’t know what’s wrong with them but you know what’s not wrong with them. How do we explain that to our patients?

I think you have to be honest there’s two elements to it. The first is you can give them a potential diagnosis. So you can say I don’t think it’s anything serious but it’s probably muscular skeletal in your case or it’s probably gastroesophageal reflux disease. So you can make a stab at what it is about something which is not terribly serious which may reassure them. You can be absolutely honest and say I don’t know what it is but it’s not serious. I’m not going to handle it today by all means followed up with your general practitioner. But lastly and this is because I have an interest in diagnostics as you do in is you can never be 100% sure about any of these things. So when I do speak to patients I will say at this moment in time I can’t find anything serious wrong but please if anything changes if you’re worried if your symptoms get worse if anything else happens that you can’t explain. Please just come back and see us. We’ll always have another look at you. Always happy to see you again. We’re always open because there will always be those very small number of patients who don’t show those classical symptoms signs or ECG changes or chest X-X-X-R changes on day one who will come back. And if they come back knowing that you told them to come back that’s great. If they come back thinking that you told them to go away and there was nothing wrong with them they’ll be quite cross. So be nice to your patients. And we’ve talked about this before but part of being a good emergency physician is making sure that we target our investigations, target our treatments in the best way to the patients that need them and we will have the odd occasion and it will be only very occasionally where we don’t spot what’s wrong. So we need to make sure that we reassure the patient to come back whenever they need to. And this decision-making process is all part of being a good emergency physician whether you’re just starting working in an emergency department or whether like myself and Simon and others you’ve been doing it for several years.

Simon is there anything else you want to add about chest pain before we round things off? Just that you’ll see a hell of a lot of it you’ll get good at it and be nice to everybody. Always be nice to everybody. Enjoy your emergency medicine everyone take care and we’ll see you soon for another St. Emelon’s podcast.