To CT or not to CT???

Is it ok to cancel an investigation that someone else has requested? 

Ben and I reflect on this as we analyse a case of shortness of breath and weight loss. 

What would you do in this situation?

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Disclaimer: All patient stories discussed in Home of Medicine are informed by real patient interactions. However, all identifying details have been removed or appropriately modified to protect patient confidentiality. 

This podcast is intended for education and professional development and should not replace independent clinical judgement or specialist consultation.

Transcript

Dr. Ben Lovell: Hello everybody and welcome to Home of Medicine Podcast. My name is Ben Lovell and I'm a consultant in Acute Medicine working in London and I'm here with my colleague and co-podcaster, Amie. 

Dr. Amie Burbridge: Hi, I'm Dr. Amie Burbridge. Nice to be back, as always, Ben. 

Dr. Ben Lovell: So it's my turn today, and I've got a case for you. And it's a case of a patient who I saw on the Acute Medical Take, which is my favourite place in the world, in A and E Resus, which is my favourite place within the emergency department. So this is a referral to medicine, a 48-year-old woman with no significant past medical history. And she presented to hospital with actually an insidious sort of three-month history of shortness of breath with a dry cough. And she felt unwell, increasingly unwell, over the last three months and especially the last two weeks. And today the cough was so bad and she felt very breathless. So she decided to come to be checked out in the emergency department. And she'd lost a bit of weight over the last three months as well, associated with this. The last seven days had been really rough for her. She described herself as pretty tough and sort of hospital averse, but she really tried to cope at home. But she'd had a real worsening of the breathlessness, much reduced exercise tolerance, simply a hundred meters for having to stop and pant and get her breath back. And normally she had unlimited exercise tolerance, and she's just completely off her food, no appetite, not eating and drinking at all. And that was her presentation, really. She didn't know other symptoms of note. Any first thoughts? 

Dr. Amie Burbridge: So the first question I want to ask is why were you in Resus with the patient? 

Dr. Ben Lovell: She'd been moved to Resus because she apparently had enough features to flag up for query sepsis and was moved into by the ED team. So we'll find out in a bit, but her observation showed a hypoxia, a tachycardia, and a slightly saggy blood pressure. So that's why she was in the Resus. 

Dr. Amie Burbridge: Okay, excellent. So 48-year-old female, three-month history of shortness of breath, cough, breathlessness, reduced exercise tolerance. Did she say that she'd lost some weight? 

Dr. Ben Lovell: Yes. 

Dr. Amie Burbridge: Yeah, okay. I don't know how much. 

Dr. Ben Lovell: It was about three or four kilos, enough for her to notice, but not a huge amount of weight loss. 

Dr. Amie Burbridge: Okay, and she'd lost her appetite as well. Okay, so there could be many things going on here. There could be one diagnosis, there could be more than one diagnosis. So the first thing that comes into my head is is this cancer? Is this malignancy? The weight loss, the decreased appetite, the feeling unwell. Oh, my mind just goes straight to malignancy. And I think that's my primary diagnosis that I need to make sure that she doesn't have. However, you said that she's also acutely unwell. So my acute brain is thinking, is this sepsis, shortness of breath, cough? I'm also thinking, could this be a blood clot? Could it be a pulmonary embolism? Could it be multiple pulmonary embolisms? Could this be an autoimmune lung disease? Could this be? I'm really thinking a bit strange now to be honest, could this be a vasculitis that's causing lung disease? Could this be cardiac failure? I know she's only 48, but she's short of breath. Hmm, appetite, sorry, exercise tolerance is down, but she'd lost weight. And I guess if I'm thinking cardiac failure, she may be retaining fluid, and sometimes people notice that they gain weight. So I'd want to take find a little bit more about cardiac conditions. So is this a respiratory cause of shortness of breath and cough? Is it a cardiac cause? Is it an autoimmune cause or or is it something like a malignancy? That's where my mind is at the moment. 

Dr. Ben Lovell: Okay, so really wide differential there covering several body systems. Very wide, absolutely. 

Dr. Amie Burbridge: Yeah. 

Dr. Ben Lovell: That's fine. You can go into a scenario with an open mind as long as we gently close it as the history develops. So just to give you a bit more information, she was very, very short of breath, no chest pain, no preceding symptoms, such as a nasty virus, which set all this off, for example. And she had a very dry cough. She wasn't bringing up sputum, but it was a hacking dry cough, the kind of cough you can hear from the other end of the department, coughing like crazy. And she was her respiratory rate was quite elevated, actually. And she was normally incredibly fit and well, she had no past medical history of note, she wasn't taking any regular medications, she did not smoke. She drank alcohol socially, maybe once or twice a week. She worked in interior design, and I went to have a look at her in Resus. End of bedogram, she didn't look very well. She looked clammy, she looked sick, she looked miserable. Her saturations as she walked in the door were 92% on air, so she'd been placed on oxygen, and they'd corrected quite nicely with four litres of oxygen by a nasal cannulae. I examined her chest, no crackles, no wheeze, no added sounds at all, and I had a look all over. Her calves were slim, there was no retained fluid, there was no signs of a peripheral DVT, but she was tacky, her heart rate was 122 sinus rhythm, blood pressure was 102 over 67, and her temperature was 36.9, so she was afebrile. Her heart sounds were normal, for what it's worth. And I couldn't really elicit any other signs on physical examination. So, what do you think about that? 

Dr. Amie Burbridge: So, just to clarify, her chest examination was completely normal. 

Dr. Ben Lovell: Chest was normal, yes. 

Dr. Amie Burbridge: Ooh, okay, so but she's hypoxic, tachycardic, and hypotensive. 

Dr. Ben Lovell: Yes. 

Dr. Amie Burbridge: So could this may be infection? I mean, I know her temperature's low, but it could be infection. She could be immunocompromised, it could be a pulmonary embolism, potentially, because of the tachycardia and the hypotension and the clear chest. Often you don't find anything on examination of the chest in a PE. It's sort of my differential included cardiac failure and there was no P. JVP? 

Dr. Ben Lovell: Was not elevated. 

Dr. Amie Burbridge: Okay, so I sort of clinically that's going against that. Did she complain of orthopnea or any paroxysmal nocturnal dyspnea? 

Dr. Ben Lovell: She didn't describe that at all. She said her shortenedness of breath was pretty much constant and she was coughing a lot, but she didn't say worse at night, worse laying down. 

Dr. Amie Burbridge: Has she had COVID sort of three to four months ago before this all started? 

Dr. Ben Lovell: What does she know of? And that's why I said I said to her, Did you have a nasty viral infection that set all this off at the beginning? Because I do sometimes wonder about that, whether someone had COVID and then they got super added bacterial infection and things after that, or or we did see in in the big COVID waves of 2000, we saw a lot of venous thrombolembolism, so a lot of PEs, but no, she had never tested. 

Dr. Amie Burbridge: Okay, it could still be malignancy, potentially, because of the chronicity of it over three months. It could be another type of infection, so TB, potentially. Could this be pneumocystis? Because sometimes with pneumocystis, you get the hypoxia, but you don't necessarily get any findings on auscultation of the chest, potentially. I'd like to do a HIV test just to make sure that she's not immunocompromised from HIV. Does she take any medication that could be causing lung damage? 

Dr. Ben Lovell: Like what? 

Dr. Amie Burbridge: I'm thinking amiodorone. 

Dr. Ben Lovell: Oh, you mean like amiodorone, lung fibrosis? No, no, nothing like that. 

Dr. Amie Burbridge: Okay, so she hasn't got lung fibrosis. Okay, and to be fair, if she had lung fibrosis, she'd hear that probably hear that on auscultation anyway, wouldn't you? So this is a tricky one. 

Dr. Ben Lovell: I'll tell you that there was a chest x-ray which was really clear. A tiny rim of fluid was the only thing. Well, like no, not even a tiny little blunting of the diaphragm we noticed, which indicated a tiny effusion, which that the left base, but otherwise the chest x-ray looked clear. Now, ED had looked at the patient, they've said hypoxia, normal chest x-ray, normal chest exam, tachycardic, we need to screen for a PE. And they'd actually requested a CTPA. Hadn't happened at the time we I came to see her yet, but that was in the pipeline. And would you like some blood tests? 

Dr. Amie Burbridge: Yes, but also one question did you consider POCUS in this case? 

Dr. Ben Lovell: Oh, Amie, you've seen my notes. Yes, I did. 

Dr. Amie Burbridge: I haven't seen them. 

Dr. Ben Lovell: I know when that's because we're hundreds of miles away from each other, but that's an excellent what what POCUS of what? 

Dr. Amie Burbridge: Pocus of the lungs, because so chest x-rays don't show huge amounts of the lungs. So I guess you're probably going to be looking at 50 to 75 percent of the lungs. So, what about the lungs that we can't see from this two-dimensional image? But actually, we need 3D images such as POCUS. So I am a massive fan of POCUS now, having been trained in its use sort of the last few years, particularly in the lungs, because you can identify now the normal chest x-ray, you put a probe on, you're like, oh my god, there's fluid. Oh my god, there's those jellyfish that are wobbling around that indicate infection. You know, there are so many things that you can see. Are there bee lines on there that can indicate that there could be fluid that you just don't see on a chest x-ray? And it can be so, so important. 

Dr. Ben Lovell: Well, yes, you you've convinced me. I'm just adding in because we were in our last no two episodes ago, I think, we were in Florence at a live conference doing doing a really brilliant session at the European Federation of Handel and Medicine. One of the feedbacks we got from our international listeners was sometimes we talk very fast and we use a lot of UK acronyms that they just struggle to follow in their second language. So we're talking about POCUS, which is point of care ultrasound, bedside ultrasound testing, which has had a massive explosion in understanding training, and especially in acute medicine, which is now a mandated part of the acute medicine curriculum because it is an incredibly powerful diagnostic tool, as you say, at the bedside for realistic sort of in-time diagnostic intervention. So we did do poke. I didn't do it. I'm so sorry, I'm not trained, and I I wonder if I'm too old to learn new tricks, but the the new generation are. 

Dr. Amie Burbridge: I'm gonna stop you there, Ben, because I've just learned how to do point of care ultrasound in the last two years. 

Dr. Ben Lovell: So teach me. 

Dr. Amie Burbridge: It it's been hard, like it's been really difficult, but I've had a brilliant teacher. We have a poker's fellow working with us, Chris, who's an F2. I mean, his knowledge is phenomenal, and his enthusiasm and passion for pocers has sort of passed on to me. So I now feel confident with long DVTs, abdomens, you know, sort of the brief bits of abdomen, but I I mean I'm not going to be learning how to do echoes because I just think that's probably past me. But we're never too old, Ben. 

Dr. Ben Lovell: I actually do know how to echo because I'd learnt it when I was an ST3 in cardiology when I was doing my cardiology rotation of acute medicine. But lung ultrasound, I just see white blotches on the screen. Okay, it's on my long list of things, things to conquer in my next appraisal. So, anyway, my patient. So the acute medicine registrar who was on call with me, who is the future of acute medicine and therefore is poker strain, came and did some poker and actually found on the left posterior dense consolidation of the lung. And I'll tell you that the blood results showed a CRP of 270. So, where are you? Where are you now mentally with this patient? 

Dr. Amie Burbridge: So, dense consolidation, CRP200, this is infection until proven otherwise in my mind. And given the hypoxia and the tachycardia, the dense consolidation, the hypotension, what was the respiratory rate by the way, and the lactate? 

Dr. Ben Lovell: Oh, the lactate was 1.8, and the respiratory rate was about 2022. 

Dr. Amie Burbridge: Okay, so I would actually treat this as sepsis. Um, I know I know that the lactate's okay, but actually, you don't necessarily have to have a high lactate for this to be sepsis. So I would treat with oxygen, IV antibiotics, IV fluids, yeah, um, and very closely monitor. 

Dr. Ben Lovell: Yeah. 

Dr. Amie Burbridge: If there was not much improvement, i.e., urine output wasn't great, blood pressure stayed low, heart rate stayed high, I would also consider contacting critical care and getting some support if needed. 

Dr. Ben Lovell: Okay, so you're treating this as a community-acquired pneumonia and SEPS secondary to that. Okay. 

Dr. Amie Burbridge: So yes, at this moment in time, yeah. 

Dr. Ben Lovell: So cancel the CTPA then because we don't need it. 

Dr. Amie Burbridge: No, no, I wouldn't. So she could still have a PE because patients, as here comes dictum, patients can have as many diseases as they damn well please. Is it's a tricky one. 

Dr. Ben Lovell: Well, the POCUS isn't is POCUS alternate is meant to be a nice non-ionizing radiation way of making a diagnosis that that sort of obviates the need to to get cross-site limiting and ionize patients. And an argument would be we have made the diagnosis now using our clinical acumen and POCUS. What why go why keep testing? Because the the CPA was requested at a different point in the patient's journey when the number one was PE, but now the number one is quite definitely pneumonia. We've seen the consolidation. Um, I guess you can always say, I think she's got pneumonia and PE. I've seen it, I've seen that. Um yeah, and it's quite tricky sometimes to work that out because they both present very similarly. Hypoxia, the existence of pleuritic pain doesn't necessarily point just towards PE because you can get really nasty pleuritic pain with pneumonia as well. Um, so it can be quite difficult to tease out, but you know, the the porters are going to come to take it to the CT scan. Yes or no, CTPA? 

Dr. Amie Burbridge: Oh gosh. So I've got a diagnosis in front of me. Oh gosh, I am going to do the PE, the CTPA. Now it's a really difficult one because I'm now starting to think, okay, has she got a huge PE and she's infarcted? And if the consolidation is infarcted tissue that we can see, she hasn't got a temperature because this isn't infection, it's just blood and necrosed tissue from this massive PE that she'd had. So I'm starting to now really worry that this is a PE. 

Dr. Ben Lovell: Um but if ED hadn't arranged the CTPA, would you now be requesting one? 

Dr. Amie Burbridge: No, I wouldn't. 

Dr. Ben Lovell: So it's the fact that it's already been requested as making you want it, I think. Is that it? Uh that it's already been organized. So you're just not not cancelling it rather than actually requesting one. I'm just really interested to know how what's influencing the thinking. 

Dr. Amie Burbridge: But the fact that it's already been requested means that somebody else has already thought of this. So have they thought of it of a PE and have I not thought of it? So does that mean that their thinking is different to mine? And who's to say that mine is right and theirs isn't? 

Dr. Ben Lovell: But they thought of it because they hadn't got the poker showing consolidation. They were looking at a clear chest x-ray. 

Dr. Amie Burbridge: That's correct. I'm also thinking if I don't do the CTPA and she doesn't get better and she has a massive PE, then four days down the line they'll say, Well, why did you cancel it? I did we requested a CTPA. Why did you cancel it? I thought it was a PE. I don't know. 

Dr. Ben Lovell: I am genuinely thinking about this on on as I'm now and I I'm I'm like that that you're that it's not an easy one for you because I don't think it is an easy one. Um, because I think it's a nice insight as well into it is so much easier in in many scenarios in medicine to look at the path of least resistance. To cancel the CTPA requires getting through to someone and doing something, whereas letting it happen, I don't have to do anything. And if I imagine I'm in an incredibly busy unit with a lot of demands on my time, if someone said, Do you want to call and cancel that CTPA? Then I'm not saying that we should do unnecessary tests for patients because we're too busy, but it might influence what I do. I might talk myself into saying, Ah, but we'll do it actually. And I can think of a justification for that now to make that fit. I'm sure that drives us. Also, um, it's it takes a lot of gore sometimes to undo someone else's plan. Um, I find that when I see people on the acute medicine unit, and if I want to go against maybe what the post-taking consultant wanted to do yesterday, like my colleague, my consultant colleague. I even find it tricky sometimes if um the doctor, the resident doctor, the reg or the SHL, what have you, is presenting a patient to me to post-take, and they'll say something on the lines of, oh, and I also they had a couple of troponin come back which were not very elevated. I think we could ignore those. So I've not done anything anyway. I'm more likely to go, yeah, yeah, that sounds reasonable. Rather go, hang on, hang on, whoa, whoa, whoa, slow down. Well, what do you mean a bit elevated? Just go through that bit with me because you can get swept along by um someone else's thinking, especially if someone that you know, you trust, you respect, they make intelligent decisions, and what the impact is on your workload and your cognitive load at the same time as well. 

Dr. Amie Burbridge: So the answer to your question, would I do a CTPA or not, isn't as simple as yes or no. All of these the things that you've just described are going on in our heads. Um, and another option, I mean, I've I've been asked this question many times, probably most days when I'm at work. And should I cancel it then? Should we do this? And I'm just like, oh, just cancel it, it's absolutely fine, no problem, cancel it. And a couple of times I've said to cancel it, and the person's disagreed with me and they've done it anyway. Yeah, it's fine. Um, that's absolutely, you know, that's that's um no problem. And I I go back and say, Well, I just noticed that you I'd asked you to cancel that CTPA, but you did it anyway. I just wondered why. Yeah, so again, it's really important to understand that. But another option would be to say, actually, we don't need the CTPA now. Let's treat this lady with the antibiotics and the oxygen. If she doesn't get better, then we could consider or she gets worse, then we could consider doing a CTPA because we could be a PE potentially. 

Dr. Ben Lovell: Yeah, it's not never do one, it's just don't don't do it right now because I think we've got enough to go on. 

Dr. Amie Burbridge: Yeah. 

Dr. Ben Lovell: Do you want to know what I did? 

Dr. Amie Burbridge: Go on. 

Dr. Ben Lovell: So um they asked me the question, do you still want this CTPA they've requested? My response was no, why would I want it? You've just told me there's consolidation and she's got pneumonia, treat us pneumonia, that's that's that's fine. And I assumed the CTA being cancelled. Um, in fact, it wasn't because they it they it was they were so efficient in the radiology department, they came down and whisked the patient off for a CTPA quite quickly before my team had a chance to cancel. So she actually had the CTPA, even though I said please don't do one. Yeah, CTPA result was dense collapse of the left lower lobe, secondary to a left posterior mediastinum tumor compressing the left lower lobe bronchus, no pulmonary embolism, but enlarged mediastinal lymph nodes could be in keeping with diagnosis of lymphoma. 

Dr. Amie Burbridge: Oh gosh. 

Dr. Ben Lovell: And that's a scan I didn't want. 

Dr. Amie Burbridge: Wow.

Dr. Ben Lovell: So how do we where do we put this in our brains? What has happened here? Is it a good thing that's happened or a bad thing that's happened? And how do we justify all of this and sort of make sense of it all within the framework of clinical reasoning and diagnosis? 

Dr. Amie Burbridge: I mean, I guess we have just alluded to all the reasons why we would and wouldn't do it. I mean, she wouldn't have got better. So if we didn't, if you hadn't have done the scan, she wouldn't have got better. We know that. And she may have continued to lose more weight, become more breathless, reduce exercise tolerance and appetite. So she would have had a CT at some point, which would have picked this up potentially. However, the CT scan was done, and that sometimes happens in medicine, and that's life. And we've found a diagnosis and great for the patient. And what can we learn from that? 

Dr. Ben Lovell: Yeah, I that's what I want to know. What can I learn from that to grow and develop continually as a healthcare professional? Because I'm not done yet, I'm still learning, I'm still developing professionally. And do I one way of looking at it is how lucky for the patient that they didn't cancel the scan that I said to cancel. Um, you're right, I think it would have been picked up eventually, but it would have been a bit delayed, right? The diagnosis would have been a bit further down the road. But on the other hand, I can't CTP every single case of pneumonia comes in in case one of them has got a lurking lymphoma underneath it. 

Dr. Amie Burbridge: But this case was different because she'd been unwell for three months. 

Dr. Ben Lovell: Yeah. 

Dr. Amie Burbridge: So let's so if we reframe it, and you know, if I saw a patient in AE recess tomorrow who had a history of three days of shortness of breath, cough, pyrexia, I wouldn't necessarily do a CT on that individual. However, if we go back to the history, the diagnosis was in the history, not necessarily of lymphoma, but about being more chronically unwell, three months of being unwell, losing weight, decreased appetite, you said that she looked really unwell that didn't necessarily fit with the just pneumonia. So if we go back to the beginning and say, well, actually, and you even said she didn't look well, would that fit with a 48 year old with pneumonia? Or is there something else going on? 

Dr. Ben Lovell: I think that's key actually. I think it's the preceding several months of systemic. Systemic unwellness. Yeah. I think that's what I that's what I've taken away from the case, really, really. And it's like you said, patients can have, you said right at the beginning, as many diseases as they like when they come in. And um, there is a in clinical reasoning there's something called premature closure, which is when you stop early, yeah, um, and you say you stop thinking. And um, maybe that's what I was guilty of there, a bit of premature closure and not saying, okay, but what else? 

Dr. Amie Burbridge: It's also confirmation bias, isn't it? Where you you've taken a history, you think it's pneumonia, you confirm the diagnosis with the poker scan, it had consolidation, you have the CRP and the tachycardia, you've confirmed the diagnosis. I don't need to look for anything else now because I've got the diagnosis there. Yeah, however, what you don't want to do is to have hindsight bias now, where every patient you see who has shortness of breath and a cough, you go, Well, I missed a lymphoma or I could have missed a lymphoma. So therefore, I need to check every patient for lymphoma. 

Dr. Ben Lovell: Yeah. 

Dr. Amie Burbridge: So I guess it's it's a balancing act, isn't it? 

Dr. Ben Lovell: Well, no doubt I'll be more sensitized now to the possibility in the history taking. 

Dr. Amie Burbridge: But we also this also raises a really important question about the validity of chest x-rays. So the the CT findings were significant, highly lymphedinopathy, collapse consolidation, and a dense consolidation. The chest x-ray look normal. 

Dr. Ben Lovell: Yeah. 

Dr. Amie Burbridge: Should we be doing chest x-rays? Should every patient have a everyone gets one, every yeah, but you know, and if you have a normal chest x-ray, does that mean that there's nothing wrong? I don't know. 

Dr. Ben Lovell: Well, not in this case, exactly. I I guess if anything, it's a very supportive case for the development of poker skills. 

Dr. Amie Burbridge: Yeah, absolutely. Very good case. 

Dr. Ben Lovell: Did you like it? 

Dr. Amie Burbridge: I really liked discussing the bias again. And it's a it's a beautiful case that really we talk about clinical reasoning. And actually, I'm gonna say it, I say it every single episode. Listen to your patient, they are telling you the diagnosis. And I'm not saying that by listening to this history, it would have taught it would have gone to lymphoma, but by listening with the three-month weight loss, all that sort of stuff, actually, that's something else is going on. We need to latch on to that and find out what that is. 

Dr. Ben Lovell: No, I completely agree. The pay listen to the patient, they're telling you the diagnosis, often hidden within several. 

Dr. Amie Burbridge: Yeah, and that's the beauty of clinical medicine and that patient interaction and taking history, because it's all in there, it's all in the communication. 

Dr. Ben Lovell: So, thanks for um analysing that case with me, Amie. So a nice conversation about clinical clinical reasoning and diagnostic uncertainty, which is really the heart of what we're doing trying to do here at Home of Medicine. And thank you so much, people, for listening and guessing along. And I hope that you were thinking as well when I was asking Amie the question about would you or would you not continue? You you were going yes or no as well, because I think it's it's more fun if you join in as well. Um and we're presenting the cases as much as you as much to each other. Thank you so much for listening to Home of Medicine Podcast. We have been doing plodding away this podcast for years because we love it, um, and it's sort of slowly growing um bit by bit. Um, and if you could help us by going to wherever you listen to it and rating or reviewing or leaving us a comment and we read every single one and then we text them to each other and get very excited whenever we get um positive feedback, or you can drop us an email as well. Um, but we love, love, love getting feedback that you enjoy the podcast and maybe you listen to it whilst you're doing your run or on the commute or something like that. And please do tell your friends if you do enjoy it because we'd we'd love to connect with some more people. Thank you so much, Amie. Great to see you, and I'll see you next time. 

Dr. Amie Burbridge: Thank you for listening. Goodbye.