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S2D: The Symptom to Diagnosis Podcast - Episode 15: Dyspnea
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S2D: The Symptom to Diagnosis Podcast - Episode 15: Dyspnea
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T00H34M35S
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Upload Date:
2023-06-03T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
[upbeat intro music]
DR. CIFU: I'm Adam Cifu.
DR. STERN: And I'm Scott Stern.
DR. CIFU: And we're here with dyspnea--
DR. STERN: Oh, boy.
DR. CIFU: [chuckles]
DR. CIFU: -on S2D, the Symptom to Diagnosis podcast. You got to love those classic medicine topics. Right? Dyspnea, abdominal pain, chest pain.
DR. STERN: [chuckles] Yes, sir.
DR. CIFU: Okay, so Scott, you're the expert of the day. Do you have a case to present to me?
DR. STERN: I do--
DR. CIFU: Wait, wait, let me guess. Is it someone who's short of breath?
DR. STERN: You know, your insights are just breathtaking. [both chuckle]
DR. STERN: Anyway, so this is a case, believe it or not, of someone I saw when I was an intern which was a very long time ago, 1984, to be specific. I saw her in the emergency room. She's a 52-year-old woman who presented to the emergency room, actually short of breath. She said, she'd gotten so short of breath, she couldn't even work around her house, she'd have to stop to catch her breath. She first noticed it about three months ago and it's been getting worse and worse.
DR. STERN: Prior to that she could walk around with no problem whatsoever. And there weren't any obvious clues, she wasn't a smoker, she didn't have fevers, chest pain, or other symptoms. She had no prior history of asthma or heart disease. And as a matter of fact, her past medical history was completely unremarkable.
DR. CIFU: That's all you're going to give me?
DR. STERN: Well, okay, so on physical exam, her vital signs were normal and her heart showed a regular rate and rhythm without murmur, gallop, or rub as we say, and her lungs were clear. How's that?
DR. CIFU: [chuckles] So you're not giving me anything else.
DR. STERN: I'm not giving you, I didn't have anything else. It was quite hard.
DR. CIFU: [chuckles] That's tough. I guess this happened in, you said, what? 1954 or so?
DR. STERN: No, '84, thank you very much.
DR. CIFU: [chuckles] I was thinking pneumonic plague.
DR. STERN: Yeah.
DR. CIFU: Yeah, so it's an interesting case. So a 52-year-old woman doesn't tell us a whole lot, she sounds like she's healthy to begin with. And it's interesting because I usually think about shortness of breath as, is this chronic shortness of breath? Is this acute shortness of breath? This is somewhat chronic, it's been going on for three months, but it sounds like it started pretty acutely three months ago, is that true?
DR. STERN: It was hard for me to say, it's clearly progressed from somebody who had no clear exercise intolerance to incapacitating intolerance.
DR. CIFU: Okay, okay, so at very least it's been sort of rapidly progressive in her.
DR. STERN: That's right.
DR. CIFU: And when I think about the things that come to mind immediately as common causes of dyspnea, I think of heart failure, I think of COPD, I think of asthma. You know, none of those make sense here. You know, I guess, could she have had an MI which was silent and had worsening of her ejection fraction and pulmonary congestion? Though I'm not hearing any other signs of CHF. I haven't heard about edema, haven't heard about paroxysmal nocturnal dyspnea.
DR. STERN: That's right, she didn't have any of that.
DR. CIFU: Okay, she's not a smoker, so that would make COPD incredibly unlikely. She doesn't have a history of asthma so it would make new asthma in a woman of this age very unlikely. So it's a tough case. The other, you know, infectious disease doesn't really make any sense, she doesn't sound like she's had fevers, not even cough?
DR. STERN: No. No cough, no fevers.
DR. CIFU: Okay, hasn't been losing weight?
DR. STERN: Has not been losing weight.
DR. CIFU: Okay, so a chronic pulmonary infection would be unlikely too. So I think what I'm getting to is, I'm getting to either atypical presentations of things we see a lot or some more zebra-y things. Things I never want to miss is pulmonary embolism. Right? I've certainly seen my share of PEs present in a subacute and atypical way. I guess that's a possibility for this woman. If she ended up having PEs, I'd be worried about why she was having PEs but that would be a whole other story.
DR. CIFU: I guess I would think about other, you know, interstitial lung diseases, things which could progress kind of quickly, those might be the idiopathic pulmonary fibrosis, it could be the allergic interstitial diseases. It could, you know, God forbid, be malignancy with metastasis to the lung, I'd sort of expect for other symptoms in that case, and she is young for that, but that's a possibility.
DR. CIFU: So I guess that's where I'm going to go and I'll ask you, do you want me to ask for tests now? Or should we get back to that after we talk a little bit?
DR. STERN: Let's do it after.
DR. CIFU: Okay, okay.
DR. STERN: Let's do it after.
DR. CIFU: I guess the one thing I would say is that because I'm so lost after the history, she is someone who I'd pay a lot of attention to what her exam was like, because I'm sort of trying to find something that I could go after.
DR. STERN: Sure.
DR. CIFU: So not only would I check her vital signs but I'd look back and I'd see, you know, is she actually more tachycardic resting in the office than she has been previously? Let me re-check her weight. She's not someone who I'd listened to and, you know, two spots on her back and leave it at that, I would really make sure I'm listening over the skin, listen all over her lungs. I'd really do a good heart exam.
DR. CIFU: I'd actually have her lean forward, I'd get her into left lateral decubitus position to listen to her heart. And then I'd really look her over for edema as well.
DR. STERN: Let me ask you a question, I won't give you the answer to this, but what will be your first line tests for her?
DR. CIFU: So, this lady is not leaving my office without a CBC to see if she's anemic because I always like to think about, what are the non-cardiopulmonary things. I'd be checking at least a BMP, basic metabolic panel, to make sure she's not acidotic. Right? Which would be another cause.
DR. STERN: Right, sure.
DR. CIFU: And I think I would be doing both a chest X-ray and an EKG before she leaves the office. I think the money's probably going to be in the chest X-ray, but if all of a sudden she's got anterior Q waves that would tell me a lot.
DR. STERN: Right, I think those are all reasonable tests and we've certainly-- She's not going to turn out to be anemic, so I'm happy to give that away but we've certainly both seen patients who present just like this who've had a progressive anemia and they present with dyspnea, it's not all that uncommon actually.
DR. CIFU: Right. Okay, so let's leave the case and we're going to take a deep dive into dyspnea. Scott, you're going to give us five key points for the diagnosis of shortness of breath.
DR. STERN: I am, so dyspnea is a tough one, I have to say, I've been looking at this since we started on the book in 2002 and it's challenging. The differential diagnosis is pretty easy to remember if you think about heart and the various components of the heart going from pericardium to myocardium to valvular disease and the electrical system. And think about the lung and think about it anatomically as well, think about alveoli, and interstitium, and blood vessels, and pleura, and bronchioles.
DR. STERN: It's pretty easy to remember the differential diagnosis. The trouble is that even given the differential diagnosis of heart, blood, lung, none of the questions are really terribly good on history and physical to segregate is this a heart problem, is this a lung problem, is this a blood problem? And that's really unfortunate. One pivotal question that is somewhat helpful but only marginally so, is the chronicity.
DR. STERN: So we can certainly divide things into acute and chronic, and when we think about acute dyspnea, we think about MI, PE, asthma, pneumothorax, pneumonia, arrhythmia, it's still a long list, acute aortic regurgitation, panic attacks. But that's complicated because a whole bunch of chronic conditions will occasionally present acutely. Heart failure can present with an acute exacerbation when somebody has a salt load.
DR. STERN: Asthma can present acutely, COPD can be relatively quiescent until someone gets an infection and all of a sudden they're much worse than they were previously. And conversely, when we think about chronic dyspnea, we think about COPD, and heart failure, and interstitial lung disease but occasionally conditions like PE and asthma will present both acutely and chronically, so it's not a clear cut distinction given all of that.
DR. CIFU: Yeah, I think of shortness of breath very much in the way I think of chest pain, is that I start with acute and chronic, I recognize they have different differentials. Acute, you're going to be just all over the things that you can diagnose quickly and that can potentially kill somebody. Right? But it is true that after you sort of burned through all of those, you end up with some of the chronic things which might be exacerbating.
DR. CIFU: On the other side, the differential on the chronic side, you know, there's some chronic things you think about but then once you get past those, there are a lot of atypical presentations of acute things which can present chronically. Pulmonary embolism comes to mind first and foremost in that, if I had a nickel for every person who walked in with sort of chronically worsening exercise tolerance as the presenting symptom for their chronic pulmonary emboli, you know, I'd be a rich man.
DR. STERN: You'd at least have several nickels.
DR. CIFU: That's true.
DR. STERN: Well, that's exactly what I meant, it's a very complex event diagram, unfortunately that doesn't divide well. So our next pivotal point is actually something you said, is when we're really not sure, it's to look at those four common conditions that present all the time and to say, "Hey, is there any chance it's one of those?" So heart failure, COPD or asthma, PE, and pneumonia. And when we look for diseases, what we really mean by that is we look for a combination of do they have associated symptoms of those diseases?
DR. STERN: Do they have risk factors for those or signs? And so you can take each one of those. So in heart failure, risk factors, does she have a history, like you said, of myocardial infarction or uncontrolled hypertension? Do they have the signs of an S3 gallop, or JVD, or edema, or associated symptoms of orthopnea or paroxysmal nocturnal dyspnea. COPD is pretty easy, in this country if they're not a smoker, we can pretty much exclude it.
DR. STERN: That's not necessarily true in the underdeveloped world where there's a lot more inhaled combustible materials as people heat their homes. Asthma, you can ask if there's a family history or personal history of allergies or exercise-induced symptoms or cold-induced symptoms, and pneumonia, of course, we could look for fever and cough. And basically we have to go through each one of those and see if there's clues to any of those.
DR. CIFU: I like it when I talk about COPD, I often ask the students, I was like, you know, worldwide, or at least outside the developed world number one cause of COPD in women? And people always are like, well, it can't be smoking, otherwise he wouldn't be asking. And it's indoor cooking pollution. And I like it when we have a conversation, and we haven't talked about that, and you kind of come up with the same things to trick people on.
DR. CIFU: The other thing I was thinking of as you were going through that, it would be interesting maybe as a side episode one day, I guess, you know, we talk a lot not really on the podcast, but outside about the system one and system two thinking. Right?
DR. STERN: Right.
DR. CIFU: That kind of pattern recognition versus the slower, more kind of hypothetical deductive reasoning. And I think what's important in the pattern recognition is, what are those diagnoses that you always think about immediately? And they're generally the most common, they're certainly also the most dangerous. When we did chest pain, we talked about in the outpatient setting it being angina, gastroesophageal reflux, musculoskeletal, panic attack and no diagnosis.
DR. CIFU: You know, that's for outpatient chest pain. And you here bringing up heart failure, COPD or asthma, pulmonary embolism, and pneumonia, as those things which sort of jumped to the list. It would be interesting to do that for kind of every diagnosis we talk about.
DR. STERN: Yeah, and we could probably do that off the top of our heads because it's what you do automatically. We actually have to resist that, to use our systems which is what we use when--
DR. CIFU: Right, when you need to slow down.
DR. STERN: When we need to slow down.
DR. CIFU: Point three, I think we're up to.
DR. STERN: Yeah, so when someone presents acutely it is critical to think about a variety of must-not-miss hypotheses and I just wanted to mention those. So one is arrhythmia, and what's really helpful there just to realize whether the patient is short of breath when you're seeing them. If they're having the symptoms when you're seeing them and they're normal sinus rhythm you can pretty much take it off the list. If, on the other hand, the symptoms are episodic and they're normal sinus rhythm when you're seeing them, you actually don't know if they're slipping in and out of atrial fibrillation or some other arrhythmia at the time that they're having it.
DR. STERN: Upper airway obstruction is another must-not-miss, and I know we'll do a podcast on it but stridor is terrifying, anyone who is inspiratory wheezing, [demonstrates labored wheezing] that should make you as panicked as it makes them because it almost always suggests that it's a life-threatening problem. Acute coronary syndromes all have to be considered, aortic dissection, pneumothorax, which is why we always get a chest X-ray on people who are acutely short of breath as well as for the other possibilities of angioedema.
DR. STERN: The beauty of that is usually these aren't too hard to exclude with a good history, physical exam and some simple lab tests, simple lab tests being a CBC, a chest X-ray, and an EKG are normally going to show you with a good history and physical, those life-threatening possibilities.
DR. CIFU: I will, in a way, defend myself of the things that you just talked about. One thing I could have talked about with your case would be arrhythmia. And I have to say, in my practice and probably in your practice as well, knowing the sort of age range of the patients we take care of, that a lot of the people who come in with kind of subacute dyspnea to me are people who have gone into atrial fibrillation since my last visit with them.
DR. CIFU: Why I think it's unlikely in this patient is, you told me her vital signs were normal, I'd expect that if she was having really symptomatic atrial fibrillation she'd probably be tachycardic or at least irregular. And if it was intermittent, I would have expected to hear mostly that there were days that she was fine, and then there were days that she was really limited.
DR. STERN: Right, exactly.
DR. CIFU: Point four?
DR. STERN: Well, point four is getting at what you'd already mentioned which is when it's not clear, you do go back to that physical exam and history and say, "Is there any clue that's helpful?" You know, so clues might be on a history, if somebody had some chest pain with it, well then that would narrow the differential diagnosis, and you might think about PE. If it was acute, dissection, pneumothorax, or an acute coronary syndrome.
DR. STERN: One of the difficulties with chest pain is, people with COPD and asthma often describe chest tightness, and ischemia often describes tightness. So, it is confusing, it's not always crystal clear. On physical exam, obviously, if they had, like you'd already mentioned, JVD, S3 gallop, edema, that's when we're really going to go after heart failure. If they have crackles, it's a bit more complicated, it can be heart failure, it can be pneumonia, it can be interstitial lung disease, but basically it's to really search for those.
DR. CIFU: Yes. Yeah, I guess again, shortness of breath like chest pain, you know, people have so many ways of describing their symptoms that you almost have to have a different way of taking the history for every patient you have to figure out what does this person mean by this complaint, that it can be really frustrating.
DR. STERN: Well, I mean, one point I'll get to later is you really have to-- the time course of it and really compare what it is for them, compare with before, is really very important.
DR. CIFU: Yeah.
DR. STERN: We'll come back to that.
DR. CIFU: Okay, so Scott, that probably brings us to the fifth point.
DR. STERN: Yeah, the fifth point is use key diagnostic tests that are often helpful when you're stuck. Those would include pulmonary function tests, an echocardiogram, a D-dimer, and you know, occasionally a brain natriuretic peptide.
DR. CIFU: Great, great. Yeah, and I think it's interesting, you know, when I went to the test that I would order in this patient, I left off both D-dimer and BNP, and those are tests that certainly, I mean, we didn't use them at all 10 years ago and I use them more and more. And I think I use D-dimer very appropriately, which is in that person who's kind of low risk for PE but it's going to help you sleep well, you'll send it.
DR. CIFU: BNP, brain natriuretic peptide, I think I probably overuse. I sent it in a lot of people who are short of breath and I'm just like, I don't know, let's see if I get lucky and it's elevated and it helps make the diagnosis of heart failure. And I got to say, I've actually added that to my evaluation of edema, which I may get arrested for, because I often have to fudge the diagnosis-- - DR. STERN: [giggles]
DR. CIFU: --to get it paid for. But wherever, we can talk about that.
DR. STERN: [chuckles] We won't put anything more about that on the podcast.
DR. CIFU: Okay, let's go back to the case.
DR. STERN: All right.
DR. CIFU: Give me my tests.
DR. CIFU: You know what? Okay, just give me my test.
DR. STERN: All right, we already mentioned that her CBC was normal, her chest X-ray was completely clear. Cardiac silhouettes normal, no pleural effusions, no Kerley B lines, no revascularization, nothing.
DR. CIFU: Okay.
DR. STERN: Okay? And you asked for an EKG, normal sinus rhythm--
DR. CIFU: Okay.
DR. STERN: --no ST, T wave, Q wave changes. Nothing.
DR. CIFU: Okay. And how about the basic metabolic panel?
DR. STERN: Normal.
DR. CIFU: Okay, I think I'm going to have to call the lab and add on, and I know that I'm adding on tests that weren't available when you saw this person but I think I need to add on both a D-dimer and a BNP at this point.
DR. STERN: Okay, so the BNP was normal and the D-dimer was high.
DR. CIFU: Okay, so I should say at this point, if I was, you know, even before those tests, if I was sort of, you know, where am I? The things which are coming up now is interstitial lung disease that is mild enough that I'm not seeing it on a chest X-ray but that I would see on a CT, or pulmonary embolism. With a positive D-dimer now, I would go to a CT angiogram. I think you at the time probably had to-- [chuckles] I won't belabor the point of making fun of you, so I'll say, you know, maybe you had to do a VQ scan you know, and the difference would be, if her D-dimer was negative, I think at this point I would probably go to a high resolution CT as my next test.
DR. CIFU: So it is a bit of a branch point there based on the D-dimer.
DR. STERN: So it was interesting how this rolled out. So as I had mentioned, I was an intern. and I'd always been taught that pulmonary emboli were acute.
DR. CIFU: Yeah.
DR. STERN: And the one thing I was certain she didn't have was a pulmonary embolism--
DR. CIFU: [chuckles]
DR. STERN: --to show up to the emergency room. Spoiler alert, that's what she had. But we first did an echocardiogram to see if she had some heart failure that maybe we didn't know why she had, and that was normal. And I did a methacholine challenge test to see if this was asthma and that was normal. We didn't have high res CAT scans for interstitial lung disease, although the chest X-ray, just for everyone's knowledge it's about 85% sensitive for ILD.
DR. STERN: So it will be unusual, but not impossible. And I forget the other tests we did. And meanwhile, my attending is nudging me as it were, to get a VQ scan. And I remember getting ready to leave for the day and having forgotten to look at it. And you couldn't look at a computer in those days to find the VQ scan, you had to walk down to radiology. So I walked down to radiology and I looked across the reading room and saw this VQ scan hanging from the wall with multiple perfusion defects on it.
DR. STERN: And I thought to myself, "Uh-oh!" Sure enough, that was her. She must've had 30 small pulmonary emboli at the time making her chronically short of breath.
DR. CIFU: Any cause that you guys figured out?
DR. STERN: She was on hormone replacement therapy.
DR. CIFU: Okay, okay. She's probably also factor V Leiden positive but you didn't know that.
DR. STERN: We didn't know that either then, right.
DR. CIFU: Interesting, okay, great case. So let's move on to fingerprints, common misconceptions, pet peeves, and other random pearls of knowledge. Why don't you start us off with some fingerprints?
DR. STERN: Sure, so the two I want to talk about first are for heart failure an S3 gallop has a likelihood ratio positive of 11, JVD of 5. And I just want to relate a different case I saw several years ago, of a guy who came in asymptomatic, still playing doubles tennis in his seventies, and he had a loud S3 gallop and I was certain he had it, but I'm like, it's so odd because he's still playing doubles tennis. And I got an echo because I know it's so strikingly specific and actually his EF was 28%.
DR. CIFU: Wow.
DR. STERN: So he must've slowed down a lot in his playing tennis but he hadn't admitted that to himself.
DR. CIFU: Yeah, I think the one thing to remember with the S3 gallop and the JVD is, the kappa for those are very low. Right? That depends on the operator. You need to learn what an S3 sounds like, you need to know how to look for JVD.
DR. STERN: And that's why everyone should listen to all the patients on their service, because it is really a great skill to master.
DR. CIFU: Yeah. I'll add another heart sound, I think less difficult to hear is if you're thinking about aortic regurgitation as a cause of dyspnea, hearing a diastolic murmur, a diastolic AR murmur, has a likelihood ratio of at least 40 for AR. And that's usually a fairly easy thing to hear, easiest to hear with the patient sitting up, leaning forward, over the aortic area.
DR. STERN: Yeah, and it can radiate down to the left sternal border, the one thing I'd add to that is if somebody gets aortic regurgitation from an acute valve rupture though, you won't hear the murmur--
DR. CIFU: Absolutely.
DR. STERN: --because what happens is the left ventricle comes to a full volume because it hasn't dilated yet so quickly that the murmur is too short even though the pressures are very high. So in acute aortic regurgitation, you won't find it but it is very specific when you hear it. All right, another fingerprint. So this is another thing that wasn't around when we were trained and I'd have to say nobody better put this in my hands because I can't do it, but the point-of-care ultrasound in residents who've been trained is a fingerprint as well.
DR. STERN: For an ejection fraction of less than 40, the likelihood ratio of it being heart failure is 15. And they can actually identify Kerley B lines with a likelihood ratio of 7, so it doesn't apparently take a master ultrasonographer.
DR. CIFU: Yeah, yeah, I guess I'll jump on and add to that. Point-of-care ultrasound is also very, very, very good for pneumothorax, and you know, pneumothorax is not a hard diagnosis to make. Right? But look, it's actually easier to put an ultrasound on somebody's chest than it is to send them to radiology for an X-ray even if you're in the emergency room. So that's another really diagnostic test. Let's move on to some common misconceptions.
DR. STERN: So this is one of the most important misconceptions that we see all the time which is simply that we just emphasize how important these findings are, but when they're not there, pardon me [coughs], it means nothing. One great example of this is, there was a study of heart failure with patients with very severe heart failure where not only did they have severe heart failure, but they were volume overloaded at the time, they actually had the Swan-Ganz catheter, and the average pulmonary capillary wedge pressure in these patients was 22 which is very high, will put most people in pulmonary edema.
DR. STERN: 42% of those patients with high wedge pressures had no findings of heart failure, no crackles, no JVD, and no edema. So resist the temptation to say, "I don't have this fact, this patient doesn't have these findings, so they can't have heart failure." That's just not true.
DR. CIFU: And you can pick groups of patients who it's even less sensitive. Right? We talk a lot about COPD and heart failure, how hard that diagnosis can be--
DR. STERN: Right, totally.
DR. CIFU: I think a sensitivity of 60% in that group would be absurd, you would never expect that.
DR. STERN: That's totally true, that's a good point.
DR. CIFU: I guess I'll sort of build on this and you know, I think any student who's ever been with us knows how much we beat to death the fact that positive findings are important and negative findings are not important. Right? We've written a paper which we have submitted to how many journals?
DR. STERN: Oh, I don't know. Ten?
DR. CIFU: [chuckles]
DR. CIFU: And so I'll go specifically for PE with this. So let me phrase it this way. So you can make a PE diagnosis with signs and symptoms. Okay? That's the misconception because in fact there are so many things that the positive likelihood ratios are terrible for that you really don't need them. So I'm just going to like, I'm going to fire some off. Okay? So sudden onset dyspnea, likelihood ratio 2.7, syncope, 2.0, leg swelling, 1.9, dyspnea even 1.7, pleuritic chest pain, which a lot of people would be like, you know, like the sine qua non of PE would be dyspnea and pleuritic chest pain.
DR. CIFU: Pleuritic chest pain, positive likelihood ratio, 1.5, you know, basically worthless.
DR. STERN: It's unbelievable, except it gets to an adage, which somebody else said to me one time, which is really true. When you're sure they have a PE, they often don't, and when you're sure they don't, they often do. I think we'd beat PE to death. But if this podcast leaves you with nothing but being fearful that you have no idea how to diagnose PE, that's appropriate I think, that's okay.
DR. CIFU: I think so. You have one more misconception?
DR. STERN: I do, which is that, just so that people know, patients with PE are often not hypoxic, they don't have to be at all, that gets us into some interesting pathophysiology which I would love to delve into but I will spare the audience.
DR. CIFU: I would not let you.
DR. STERN: Oh, thanks.
DR. CIFU: I have a pet peeve.
DR. STERN: Go ahead.
DR. CIFU: Let me throw out my pet peeve. You know what? I feel like actually we're always so crazy about pet peeves, but, I think my pet peeve here is something we've already said, is that, you know, the converse of the fingerprint doesn't really exist. Right? The fingerprint is that finding that if it's there, it almost definitely suggests a diagnosis but there's no converse to that. So if something is lacking, it doesn't mean the diagnosis is not there.
DR. STERN: I think I've already spoken about my pet peeve about oxygen status, so I'm going to go onto clinical pearls. Okay? We beat that to death enough.
DR. CIFU: Let's hear a clinical pearl.
DR. STERN: I'm going to change directions for just a minute and just remind everyone that everyone that wheezes doesn't have asthma and COPD. And those of us that have been around for a while have seen plenty of patients who, believe it or not, when they get heart failure, wheeze. So be cautious about the specificity of wheezing, even though we're not specifically addressing that today it's not nearly as specific as we often think.
DR. CIFU: Right, and I think we will get into kind of a deep discussion of that when we get to wheezing and stridor. And there are a lot of symptoms associated with dyspnea that you might think are specific but are not. Paroxysmal nocturnal dyspnea, or I wouldn't say it, let's say orthopnea--
DR. STERN: Orthopnea, right.
DR. CIFU: --is a big one because just about everybody who has underlying lung disease, their respiratory mechanics are worse when they're lying down and so they'll often be sleeping in a chair, not because they have heart failure, but because they're having trouble breathing.
DR. STERN: Right, you're never going to see an asthmatic with an acute attack lying on the bed in the emergency room, they're going to be sitting up.
DR. CIFU: Right, a good point.
DR. STERN: [chuckles]
DR. CIFU: So, I've got a clinical pearl which is a weird clinical pearl. Okay? But it's one of those things that I always talk about. And it's a paper written by a real mentor of mine from the past, doctor by the name of Richard Schwartzstein, who talked about this paper when I trained, and I've got it in front of me because I have to remind myself of it, it's from 1996. So I'm going back almost as far as you. It was published in the American Journal of Respiratory Critical Care Medicine and it's called Descriptors of Breathlessness in Cardiorespiratory Diseases.
DR. CIFU: And the interesting thing about this paper-- And I got to say, it has actually not changed my practice at all, but it's incredibly interesting. One of the authors had this idea that when someone complains to us of pain, we go crazy about it, well, what kind of pain is it? You know, what does it feel like--
DR. STERN: Sharp, dull or what?
DR. CIFU: And when someone tells you, they're short of breath, you're like, "Oh yeah, short of breath." Right?
DR. STERN: Right.
DR. CIFU: And their idea was that maybe the shortness of breath that people are experiencing are actually different depending on what's causing them. So like, do people who have heart failure have different dyspnea than people who have asthma, have different dyspnea than people who have COPD?
DR. STERN: Right.
DR. CIFU: And what these guys did, is they came up with a whole bunch of questions to try to describe the different types of dyspnea, and they asked people them in the emergency room. And the key point is that, it really does seem that people who experience dyspnea from different causes are experiencing a different kind of shortness of breath, but it's not different enough, and our language isn't really good enough to use that as a diagnostic tool, but jeez, it's interesting to think about it.
DR. STERN: Yeah, I mean, it's true because some people say, "I can't get enough oxygen" and you test their oxygen and it's okay. "I can't take a deep breath." You know, "I'm short of breath." And it's often tough to tease out. Right? And I've taken just the thing, "Okay, you're short of breath."
DR. CIFU: Yeah, yeah. Okay, you got another one?
DR. STERN: Right, the last clinical pearl I would say to you is, one of the trickiest parts of dyspnea I think is figuring out whether there's a disease at all. So I see lots of elderly patients and many of them if they're asked, are a little short of breath, and whether or not that represents just deconditioning or whether that represents real illness is sometimes tricky. And so one of the things I really like to do with my patients is try to figure out what their breathing was like recently before.
DR. STERN: And one way to get at that, before the COVID pandemic, was to ask them whether they traveled, because often when people travel, they, one, have to walk around, and two, they can tell you, I went to my kid's house in December or in the summer or whatever, and so comparing that baseline with how they are now is really important. If you are a medical student and you're used to running five miles a day and you got to walk one flight of stairs and you're short of breath, that's probably abnormal for you.
DR. STERN: But in my 80-year-old patients who don't do much walking up a flight of stairs, being short of breath is probably baseline. So I just think that's helpful to keep in mind.
DR. CIFU: Yeah, it's a little bit the difference of being short of breath and out of breath. Right? [chuckles] Which is right.
DR. CIFU: The other point that came up when you were talking, for me-- and it gets a little bit to therapy, and I often think of this with asthma therapy is because, you know, dyspnea is uncomfortable. And so a lot of times people will avoid dyspnea by decreasing what they do and that makes it hard because you may feel like your patient is well controlled with whatever disease they have, when in fact, they're just not doing anything anymore.
DR. STERN: I think there's really good data about that for aortic stenosis as a matter of fact. I think that's why your question for us is really useful. People will do just that in aortic stenosis, and we say, they're not short of breath, but they're sitting around now.
DR. CIFU: Right.
DR. STERN: That's a good pearl.
DR. CIFU: My last pearl is going to be something I think I brought up, I definitely brought up talking about the case, is just remember non-cardiovascular pulmonary causes of dyspnea. Anemia, metabolic acidosis are certainly the ones that come up the most. I've definitely been burnt by both of them and have begun pulmonary workups for someone who was acidotic from their renal failure and not a great thing to do.
DR. STERN: So before we adjourn, let me ask you a question.
DR. CIFU: Yeah.
DR. STERN: So one of the other tricky ones I think is panic.
DR. CIFU: Yeah.
DR. STERN: So, we both see patients periodically where they have shortness of breath at different time periods. And what pearls would you share with folks about when you really think it's panic and you're comfortable enough not to start working it up?
DR. CIFU: Right. I think what I would say, and I'm pretty cautious here, and I'm sure you're 10 times more cautious... unless the person clearly has panic attacks. Right? Unless the person comes in and they say, "I've been having panic attacks forever, and these are my panic attacks." If the person's coming in and complaining to you of dyspnea, panic attack should not be your first diagnosis.
DR. CIFU: You may say, "Huh, I think this person might have panic attacks, but what else could I reasonably consider?" And you should evaluate that and exclude that before you really start treating them for panic disorder.
DR. STERN: Right, I mean it's so interesting because a lot of symptoms make people anxious.
DR. CIFU: Yeah.
DR. STERN: So there's good data for instance, in vertiginous people, that vertiginous patients often have anxiety about as much as people in whom the final diagnosis is anxiety, and you could imagine having a PE or AFib, getting short of breath and then feeling anxious.
DR. CIFU: Sure, sure, sure. And also, I mean, I've certainly taken care of and I am now taking care of a couple of people with really bad end-stage COPD who have anxiety, and they get anxious because they realize that they're at the end of their life. They also get anxious when they're more dyspneic and figuring out how to treat that stuff is, oh my God, a total bear.
DR. STERN: That is tricky.
DR. CIFU: So we hope you found this episode of the Symptom to Diagnosis podcast, S2D, useful and a bit enjoyable. We're going to add, if you like listening to us, please rate us on iTunes, we hear that's important. The Symptom to Diagnosis podcast, if it's raised issues for you and you want to chat with us, you can certainly tweet at me, @adamcifu. Scott Stern has intelligently stayed off Twitter.
DR. STERN: [chuckles]
DR. CIFU: As a reminder, our textbook, Symptom to Diagnosis: An Evidenced-Based Guide, takes a much deeper dive into how to think about and reason through the diagnosis of medical presentations. The book is available in print through all the usual places, on your mobile device, and also available and fully searchable via the Access Medicine website available worldwide from McGraw Hill. And it's kind of got to say, you know, as I was preparing for this, I looked through Symptom to Diagnosis and the dyspnea chapter, which was written by Bob Trowbridge, is really amazing.
DR. CIFU: You know, the questions that came up for me was, so, you know, what are the test characteristics for these various findings for heart failure? I actually looked up specifically one of the things you talked about which was rales and heart failure, and you just find anything in this chapter. It's amazing.
DR. STERN: Yeah, that's great. A reminder that the cases that we discuss are drawn from our clinical experiences but, because protecting patient privacy is part of our oath, we never discuss actual patients and most cases are composites.
DR. CIFU: I'll finish off. Remember that the music for the S2D podcast is courtesy of Dr. Maylyn Martinez. Thank you. [upbeat outro music]