Podcast – Intro to EM: Shortness of Breath

Welcome to the St. Emlyn’s podcast. I’m Iain Beardsell, and I’m Simon Carley. In this episode, we’re going to discuss shortness of breath as a presenting complaint. We’ll go through some of the causes in the emergency department and how we rule out those main life-threatening problems. If you go to the blog site, you’ll see that there’s a video produced by the Southampton Emergency Medicine Education Project that talks about shortness of breath.

So Simon, shortness of breath as a presenting complaint. When the patient turns up with that, does it worry you? Absolutely. If I go back to when I first started in medicine, I think shortness of breath, when you’re asked to go and see somebody on the ward with shortness of breath, is obviously worrying. Shortness of breath is not a good thing. But also, there are quite a lot of potential differential diagnoses, many of which are actually quite serious, and many of which have rather different approaches in terms of treatment and management. And I used to find them quite challenging, I don’t know about you.

Shortness of breath is undoubtedly worrying symptomatology. So when we approach the patient with shortness of breath, and we’re going to focus on ruling out the life-threatening or serious diagnoses that a patient could have who presents with shortness of breath, what are the ones that you mainly think about, Simon? It’ll depend a little bit on that sort of end of bedogram. So you have a quick look at the patient and get an idea. But I suppose the big ones are going to hit in my head. I think it’s like asthma, COPD, pneumonia, left ventricular failure, so cardiac failure. Pulmonary embolus is always one to watch, as it can catch people out, and pneumothoraces.

Pulmonary embolus is always the diagnosis that I think emergency physicians perhaps fear the most. So we’ll undoubtedly spend more time thinking about that at length. When you approach the patient with shortness of breath, we’ve talked in our introduction about the things you might want to do. Do you think there’s any harm to giving patients oxygen who have shortness of breath? In the very early stages, almost never. You may find later on that oxygen might not be the thing that you want to give, so certainly patients. We’re less enamored with giving oxygen in people who have had myocardial infarctions these days. And there’s all that stuff around whether in COPD, you can kill somebody with oxygen. But to be honest, you’re not going to do that if you give them oxygen for the first five, ten minutes. But you might just save their life. So my approach is very much to give the oxygen whilst you’re thinking about whether they absolutely need it. Absolutely.

And this patient with shortness of breath, if that unwell, and our first question always is, does this patient need resuscitation? They should be in an area that’s monitored and they have nursing support and you’re standing by the bedside. This isn’t the patient on the ward who you stick on high-flow oxygen and you pop back to see on the ward down the next day. So I agree entirely. I think oxygen is a good thing. We have to temper that a little bit, but in that first part of resuscitation, if that patient is short of breath physiologically, they are struggling to get oxygen into their bloodstream. And so, extra oxygen is a good thing. Shortness of breath equals oxygen. Yeah, pretty much.

So we can start giving them oxygen whilst taking the history. What are the things you’ll focus on when taking the history of a patient with shortness of breath? I think you’re looking for some big headline clues. So if somebody says, “I’ve got really bad asthma,” that’s quite a good clue that you’re heading in the right direction, although they may still have some of the other causes and particularly things like pneumothoraces. You’ll look at the age of the patient, so certain things are more common as you get older. Such as cardiac failure and COPD. And you’ll look for general clues about historical reasons that they may have come in with shortness of breath. Most of the patients I see have got a known underlying condition. If they haven’t got any underlying condition, then they’ll have associated features which might push you towards something like a pneumonia. So have they been abroad? Have they got a temperature? Do they feel dehydrated? That kind of thing. So you’re looking for clues, steering things, which are going to move you towards one of those diagnoses, or one of the less common ones, which we didn’t mention.

So focusing on asking questions that relate specifically to those top five things that could do for you if you’re not on top of it quickly. Yeah, one of the questions which I think we don’t use often enough, and I think we probably do in ED more than they do on the wards, is “Do you know what’s going on?” Or you actually say to the patient, “Do you know why you’re short of breath?” Because if they’ve had exactly the same symptoms three weeks before when they were admitted with LVF, this is probably going to be a fairly good clue that you’re heading in that direction. And we should ask for clues. This isn’t an Agatha Christie novel where we’re only trying to get the answer on the last page before Hercule Poirot reveals it all. We don’t mind if we find out who the murderer was on page two. So look for obvious clues.

So if we go through those five things you mentioned, the left ventricular failure, the obvious clues might be the history of previous left ventricular failure, the time of presentation, a certain idea of what a patient with left ventricular failure looks like. Now, if you’re a doctor who’s new to emergency medicine, that may not be something you instantly get, but your colleagues who are more senior than you will have. Drag them in to the end of the bed. And if you’re a new doctor starting in ED, these patients who present with these are the ones you need to discuss early. Get your senior colleagues in, they’re not going to mind. Hi, could you help me? I’ve got a patient who’s short of breath. I’ve given them some oxygen, but I just need some help working out the differential diagnosis.

So left ventricular failure, time of day, that’s always something that’s helpful. Four o’clock in the morning seems to be a physiological time where your lungs don’t enjoy having fluid in them. And asking the focus questions, as we said before, target your questions to the differentials you’re trying to rule out. So I’ve talked about LVF. For PE, what high-impact questions do you tend to ask there? There’ll be clues about whether or not they’ve got, say, a DVT. So somebody who turns up in the ED with a sudden onset of breathlessness with a massive great plaster cast on one of their legs, there are clues. There are always clues. And that’s what taking a history and examination is about, isn’t it, really? You’re looking for clues. So people that have usually got something else that is going on, or some associated risk factor, underlying malignancy, pregnancy, immobility, recent surgery, et cetera, et cetera. You’re looking for ideas which are going to push you in one direction. So you’re looking for clues which are going to say, I think this is probably PE, but also the absence of other factors which may push you towards a different diagnosis. So although you can get low-grade temperatures in PE, they’re not the most common thing. So if the patient has got a temperature of 40, I’m thinking I’m moving away from the PE and I’m moving more towards pneumonia and effective causes, sepsis, et cetera.

So you’re taking a whole bunch of different pieces of historical information and observation information and information from the nursing staff and pre-hospital teams to get an idea about where you’re going. But even when you’ve done that, you may still not be able to completely define a diagnosis in the first five, ten minutes, which is why, as emergency physicians, we treat before we know. And in this case, we’re going to target our treatment towards oxygen therapy if they need it. We’ve talked before in our introduction about the other things we need to think about. So fluids, if this patient looks septic or is hypotensive, there’s going to be very little harm in giving them a bolus of fluid. People will be anxious, well, what if it’s that patient with left ventricular failure and you give fluid to? Well, the actual truth is that you’re going to be able to get rid of the fluid if you need to, and you’re unlikely to do major harm in that first point of time and you can always take that fluid away if you need to.

So fluids, we’re thinking about antibiotics given early to the patient with sepsis, so that pneumonia patient, that will make a difference. And they may have pain. So the patient with a pneumothorax or patient with pneumonia, they have pleuritic pain and we should be thinking about taking their pain away as we go. So left ventricular failure, we’ve thought of those different things. Pneumonia, fever, cough, crackles when you listen are relatively straightforward. Do any of these diagnoses catch you out?

I think it’s often quite difficult to work out the difference between pneumonia and LVF in the research room, and also COPD because actually, we have patients who can present with all three at the same time. We like these five little boxes, plus all the other things which can cause problems. But what happens to the patients who cross between them? And that can be really tricky. There is a bit of a reliance on the clinical examination in those early stages, but actually clinical examination, particularly auscultation, is notoriously unreliable about differentiating, and it’s an area of practice where an early radiological investigation can be very helpful. Certainly, a chest x-ray, get it done in the research room for your very unwell patients. And increasingly, although probably not in the early stages, we’re actually using ultrasound in the ED as well to look for signs and differentiation between LVF and other causes of pneumonia.

The one clinical sign I find most useful in shortness of breath is the respiratory rate. And that’s part of our vital signs that’s done as I approach the patients. And a patient who’s tachypneic, who has a fast respiratory rate, I worry about. I think we forget it all too often because it’s just straightforward stuff, isn’t it? Vital signs are important. Tachycardia, hypotension, tachypnea, low sats, these are all things that are pointing you in the direction of a poorly patient and you’re going to be needing senior input to help and thinking about giving those interventions early.

So we’ve got a few targeted investigations we need to do. The chest x-ray may well help us, but again, with all of these things, the absence of signs doesn’t always rule out a problem. So a completely normal chest x-ray doesn’t necessarily mean you can’t have some of these problems with shortness of breath. What else would you do next? So you’re in the ED, you’re in the resus room, patient presenting with a respiratory rate of 30, you’ve given them some oxygen, you’re asking your targeted questions, how do you get that patient to where they need to be as to whether or not you need to do too much more with them?

I think I’d like some more information about the physiological status at this stage, and I think one of the great tests that you can do for anybody who’s got shortness of breath and you’re unsure where you’re going is, well, get a quick ECG. Never miss that one. But then, do a blood gas. And would you do an arterial blood gas? I think if the patient’s got low sats, yes, and certainly for the first test, first investigation in somebody who’s got acute shortness of breath, I do tend to do arterial gases. I think they’re easier to interpret in that first intervention. For later monitoring and seeing where we’re going, I can often change up to venous blood gases. But for the first test and the patient is presented solely with shortness of breath as a presenting feature, yeah, I do get an arterial.

We have moved away from arterial blood gases a bit for the most part, but that’s mainly because we’re doing venous gases on it seems everybody, but there are definite circumstances because what we’re talking about with shortness of breath is, is there a problem with ventilation? Is there a problem with getting oxygen into the bloodstream or carbon dioxide out? And the most accurate way of doing that will be on an arterial gas. We must give a little nod here to your colleagues in Manchester, Alan and Natalie, who produced a video about doing blood gases, and I think it’s worth saying here, these hurt quite a lot. And local anesthetic is just in the cupboard next to you, and you should use it. Even if the patient looks unwell, you still have time to pick up that bottle of local anesthetic and stick a bit of lignocaine in before you do it.

So arterial blood gases done with lignocaine may well be one of our first investigations and often can help, if you like, triage that shortness of breath patient as to what you need to do next. I was gonna say, sometimes pick up something really exciting and unexpected as well, such as the diabetic ketoacidosis who’s extremely short of breath because of the metabolic acidosis, you pick that up on the blood gas. Hopefully you pick it up in other ways, but you can get some really useful information early on. And venous blood gases can be so useful for that. Often our patients will get both a venous and an arterial gas, our nursing staff, especially with resus patients, part of the initial assessment for the patient does seem to be putting a cannula in and taking blood, and a venous blood gas will get run from that. So perhaps before you do the arterial, have a glance at the venous blood gas, because that will give you clues and may save the patient a painful procedure if you don’t need it.

So shortness of breath patients. Oxygen we’ve talked about, fluids perhaps, we’re gonna think about pain relief if they need it, antibiotics, get them in early. These are really the crux of what we need to do, aren’t they? Well, I think then you’re moving towards making a more refined diagnosis and doing diagnostic-specific therapy. So can I make the diagnosis of asthma? Is a respiratory pattern suggestive of airflow obstruction? Do they have wheezing? Do they have a history of asthma? Are they gonna have a bag full of asthma drugs? And then you’re going to do more focused therapy, so you’d use nebulized agents as bronchodilators and then move on to perhaps to intravenous bronchodilators. And if it’s LVF that you suspect, then you’re obviously going to treat for that, depending on what you think the underlying cause of it is, etc.

So at this point is where you’re going to start refining your diagnosis and then do diagnostic-specific therapies. But we do have a generic approach we can make to the shortness of breath patient. And if you’re a junior doctor in the ED, that generic approach is your starting point and that’s the point at which you get your senior doctor in to help. We’ve said it throughout all of our podcasts and we hope this is reflected in your departments, your senior colleagues want to help. And with these patients where we’re dealing with potential life-threatening illness, they should be standing by your side and guiding you as to what to do next. This is not a failure on your part as a junior doctor. In fact, it’s very much a positive that you’re looking for help and you’re wanting to accept that opportunity to learn about how to look after these patients.

In really well-staffed departments, and there are a few around, it’s really important that you do get the opportunity to go into resus because in a well-formed system, these patients may be skimmed off and given to the consultants and the middle grades. And as a junior doctor, you may miss out. I think it’s really bad for training. So I think if you are in that kind of department, you need to make sure that you get your foot in the door into resus and that you do work alongside your seniors so that you learn. Because one day you won’t be the junior, you’ll be the middle grade in the consultant and you need to know what to do.

And as we’ve talked about in the podcast before, there will be times when it is down to you, when your senior colleagues aren’t able to help. So get yourself a format, how you feel comfortable to look after patients with these conditions and take the opportunity when you can, but there may be a point in time where with that surge that comes into the ED, it is down to you. So get yourself into a mental model of how you’re gonna look after these patients. And I’d encourage you to do that for all of these presenting complaints. Practice in your head, how would I approach a patient with shortness of breath? And what would I do? And that can be in the car journey into the department. Do it for each of the diagnoses you might see because then this becomes almost muscle memory. It becomes natural to reach for the oxygen mask and put it onto the patient. It becomes natural to think about fluids for a patient, antibiotics. Only through that modeling will it become part of your just day-to-day work. And that takes some of the stress away. Let’s not kid ourselves. These can be stressful situations.

Yep, stressful situations, but there are situations where you can make a real difference. So they can be extremely rewarding as well.

So shortness of breath, presenting complaint that’s common to the ED. Think of the five life threats we’ve talked about. The other causes obviously of shortness of breath, but as with everything in the emergency department, we want to rule out the bad stuff first. There are more resources that you can seek out on the blog site. The C-MAP video covers these in some depth and there are also online learning modules that we will point you towards that you can then have a look at. And most importantly, probably the best way to learn is to stand with a senior colleague looking after these patients, think about what you’re doing.

Shortness of breath, Simon, anything else you want to say?

Not really, just go forth and heal the sick. Good luck with that.

See you soon!