To D-dimer, or Not to D-dimer? That is the Question

SPEAKER_01 0:11

Hello and welcome to a new episode of Home of Medicine podcast in association with the RCP Edinburgh. My name is Ben Lovell. I'm one of your hosts today, and my co-host is my friend Amy. Hi, Amy.

SPEAKER_02 0:24

Hey! Hi, I'm Amy Ferbidge, and I'm a consultant in Acute and General Medicine.

SPEAKER_01 0:28

Amy, I've got a case for you this time. All right. Another busy day in acute medicine, another busy day on the take. And we are asked to see by a local GP, a 26-year-old woman. She is 14 weeks pregnant. And she's been sent in with left-sided pleuritic chest pain. Now, if you're anything like me, your brain starts going into diagnosis mode the second you start getting the first sentences of referral. So without even knowing anything else, my brain has already thrown up. It could be A, it could be B, maybe it's a bit of C. And then I keep listening. But are you the same? And if so, what's your initial reaction to that?

SPEAKER_02 1:12

Uh yes. So, first of all, 26-year-old female. My first question is, she's pregnant until proven otherwise. But then you told me she was pregnant. So, okay, got that diagnosis. And then he said she had some left pleuritic chest pain. Now she's pregnant. So although she's quite early in the pregnancy, she will be hypercoagulable. So I'd think pulmonary embolism.

SPEAKER_00 1:34

Yeah.

SPEAKER_02 1:35

Pleuritic, I would like I think about um could this be a pneumonia? Has she had pleurisy? Has she had a recent viral infection? And number three, I'd think, could this be an ectopic pregnancy? So that's where my thought process is at the moment. Or could it just be some a bit of chest pain?

SPEAKER_01 1:53

A twinge, one of life's twinges.

SPEAKER_02 1:55

One of life's twinges, which we all get, absolutely. Yeah.

SPEAKER_01 1:59

So exactly the same as me. Someone says, Oh, please can you see a 26-year-old lady, 14 weeks pregnant with pleasure chest pain? My uh brain immediately goes, Oh, she's got a PE. But I keep listening and I keep my mind open. And as a as you say, PE may be pneumonia. So I'm listening out for shortness of breath and cough and sputum reduction, maybe musculoskeletal, as we say, a twinge. Um, 14 weeks is baby still quite small, so shouldn't be straining at the ligaments and all the cartilagine and sort of um impressing itself upon the internal ribs yet. So we shouldn't be seeing that sort of pain um at this stage in the pregnancy. But there were my initial thoughts. So time to go and meet the patient herself. Now, to give you a bit of a timeline, I actually met the patient a little bit later in her journey, and the initial assessment was done by a different doctor on the acute medical tape, and they saw the patient and they elicited the history. It's her first pregnancy. So far, so good, no complications. She's had three days of constant, what started out as left upper quadrant pain, but then quickly migrated to the lateral ribs like a stitch. Really difficult to take a deep breath in or to cough. So very classic for pleurisy. Occasionally, she's feeling some pain in her left shoulder and the shoulder tip as well. It's waking her up at night. She's struggling to take deep breaths, but she has not got a cough. She has not produced any phlegm, and she doesn't feel particularly short of breath, albeit deep respiration is limited by the pain. Past medical history is completely normal. She's never had any kind of venous thromboembolism before. And the only medication that she was taking is folic acid as part of a healthy pregnancy plan and has no allergies. She's a never smoker. She works in an accounting firm and does not drink alcohol and lives with her husband. And I don't normally do a deep dive into family history when I'm taking a history, but in this point, she's that we asked, and there was no family history of venous thromboembolism either. Because when you're making a sort of judgment in your head about risk factors, it's something that you ask for. Inherited hypercoagulable states. So that's the uh the history so far. A little pause there. Have you moved towards or away from any particular diagnosis based on that information?

SPEAKER_02 4:24

Uh so she's had three days of left upperquadrant pain. So then I started to think about what organs do we have in the left upperquadrant? Um, so we have got the bases of the lungs, which we've said, but also we've got the spleen. Um so could this be something splenic? That's quite unusual. Um, you've also got, I mean, kidneys, but they're a lot lower down, doesn't normally cause upper quadrant pain. Could it be stomach, something gastro? Potentially, but it had the pain has moved to the left shoulder and the shoulder tip. So when I think of shoulder tip pain, I think of diaphragmatic irritation, which you can get from within the um abdomen, so maybe an abdominal, something abdominal going on, either. I mean, I did say ectopic pregnancy, but it's a bit late in the pregnancy at 14 weeks to be ectopic. So that's sort of I would expect that early in the pregnancy. So has she ruptured a viscous within the abdomen? I mean, I'm really stretching things now. No cough, no shortness of breath, you said, although it's pain on deep inspiration. I still don't know that this patient doesn't have a PE. And you haven't told me anything that would say that she definitely doesn't have one, to be honest. Although she's has she's not short of breath, it doesn't necessarily mean she hasn't got one. Um I think my differential diagnosis is still very broad. Thinking of the organs in that area, I've got the lungs, I've got the spleen, some abdominal organs, some retroperitoneal organs. So that's what I'm sort of thinking about at the moment. But I'm still unsure. I want to look at her legs. What are her legs like? A calved.

SPEAKER_01 6:09

Oh, well, I'll tell you about examination. Okay. So um on examination, she was clearly uncomfortable with this left-sided pleuritic pain, really digging into the left ribs now. Um, but on examination, her chest was cleared to auscultation. With the caveulus, she really couldn't take the deep breaths that we like because she was really in a bit of pain when she took a deep breath uh uh with the pleurisy. Her legs were normal, no clinical DVT noted, no leg swelling noted. That's important, as you say. Um, and abdominal exam was normal, cardiovascular exam was normal. Her observations revealed her sats were actually 100% on remote.

SPEAKER_00 6:46

Okay.

SPEAKER_01 6:47

Her respiratory rate was 1818. Oh high. Okay. Well, really? What's your cutoff for a speech?

SPEAKER_02 6:55

Well, I guess I 12 to 14 to 16. I think 18 is still within the normal limits, isn't it? But it's at the higher end of normal.

SPEAKER_01 7:04

It is the upper limit of normal limits. It's the upper limit.

SPEAKER_02 7:07

Yeah.

SPEAKER_01 7:07

I love how we stick to even numbers though, don't we?

SPEAKER_02 7:10

Isn't that weird? I know.

SPEAKER_01 7:11

About the volume on your TV, it's got to be an even number. Half rate was 69.

SPEAKER_02 7:16

What's say about us?

SPEAKER_01 7:20

Um blood pressure 69. Yep. Blood pressure 117 over 59.

SPEAKER_02 7:28

Okay.

SPEAKER_01 7:29

And her temperature was 36.8. So they're all advice the signs for her. Um, has that colored your thinking at all?

SPEAKER_02 7:39

Uh I'm reassured that her legs have got are not a soft and on tender. I did write pneumothorax when uh for some bizarre reason because I'm thinking about um sort of uh hormoning juice pneumothorax, but her chest was clear, and I wouldn't expect necessarily 100% on rumair and normal respirate with a pneumothorax, but something in my mind maybe. Um the heart rate's reassuring, the blood pressure temperature, they're all reassuring, actually. That's a normal set of observations. Yeah. What I would like to do at this point, actually, is probably do an ultrasound scan of the lungs.

SPEAKER_01 8:18

An ultrasound? Why?

SPEAKER_02 8:20

Because two weeks ago, Ben, I got my famous accreditation.

SPEAKER_00 8:25

Which is cannot be the only reason to make a scat. So everybody gets one.

SPEAKER_02 8:31

It's taken me so long to get this accreditation.

SPEAKER_00 8:34

Oh, okay.

SPEAKER_02 8:35

Because I thought I was too old to learn a new skill.

SPEAKER_00 8:38

Uh-huh.

SPEAKER_02 8:39

Um, but what I'd be able to do in this situation is I could use the little handheld scanner that I now love carrying around with me, and I could identify straight away whether there was a pneumothorax, whether there was a collection, without exposing her to radiation. So that could be why.

SPEAKER_01 8:57

So to so you would look for um pneumothorax, yeah, and you could see flu fluid, plural.

SPEAKER_02 9:03

Yeah, I could fluid. I could see consolidation. Yeah, absolutely. You can see consolidation, yeah.

SPEAKER_01 9:09

Okay. Oh, uh we didn't have a a po uh POCUS capable person there, unfortunately, so she didn't get that. Um would you like some blood test results?

SPEAKER_02 9:18

I would love some blood tests, please.

SPEAKER_01 9:21

Uh full blood count, normal across the board. No anemia, uh, renal function usenase normal, clotting normal, CRP 81. And that's the only abnormality we're looking at here. Um she had an ECG, which showed normal sinus rhythm, and nothing uh pathological on that. And she had a chest x-ray. And the chest x-ray revealed um a small amount of left lower zone consolidation with a small rim of fluid.

SPEAKER_00 9:56

Okay.

SPEAKER_01 9:56

What's your diagnosis and what's your plan?

SPEAKER_02 10:01

So just say that again.

SPEAKER_01 10:03

She the chest x-ray showed a small It showed left lower zone consolidation.

SPEAKER_02 10:09

Okay.

SPEAKER_01 10:10

Um, with a small rim of pleural fluid around.

SPEAKER_02 10:13

And then some fluid as well. So, okay, so a tiny pleural fusion with consolidation. So what could this be? Okay, so it could be inflammatory. Um, so it could be infection, potentially. Um, you could get this in a PE. You can get consolidation and a little bit of plulifusion in a PE. So that could still be an option, to be honest.

SPEAKER_01 10:37

Um how do you get a consolidation in a PE?

SPEAKER_02 10:40

So if you get infarcted tissue within the lung due to a large PE, you can get in an inflammatory response and you can get white cells, macrophages, neutrophils, cytokase, rushed to the area and cause some localized inflammatory response, and you can get consolidation like that.

SPEAKER_00 11:01

Okay.

SPEAKER_02 11:02

It's it's not common. Um, I want to give her some pain relief because she's in pain, isn't she?

SPEAKER_01 11:09

That's a good thought, actually, yeah. And that's actually her main concern.

SPEAKER_02 11:12

It's pain.

SPEAKER_01 11:13

I can't take a deep breath in here. And uh, and I I always worry about someone who I mean, she's she's got clinical radiological signs of pneumonia. She's got a CRP of 81, she's got consolidation, and she's not gonna be able to expectuate and clear and ventilate that area if she can't take a deep breath in. So you've got to break the pain cycle, and sometimes that does get forgotten. And she'd already been saying, and um, she'd been taking paracetamol at home and it did nothing. So what are you gonna give her?

SPEAKER_02 11:37

She's pregnant, so I am therefore limited by the options, but you can give codeine in pregnancy and you can give morphine in pregnancy. So I think we often get scared of giving pain relief in pregnancy, but having had three pregnancies and been in pain, um, you know, I think, you know, opioids are safe if you are in pain because it takes the pain away. So I would go for either paracetamon codine. If it's really bad, you can consider oromorph or something. Um so I'd work up the pain ladder, avoid non-steroidals.

SPEAKER_01 12:12

Very good.

SPEAKER_02 12:13

And just to be clear, we avoid non-steroidals because they do something to the blood flow within the placenta.

SPEAKER_01 12:20

Enough said. They do something unpleasant to the blood. They blood flow across the placenta, yes. Yeah.

SPEAKER_02 12:26

Something to do with the afferent and efferent constriction of the blood vessels of the placenta to the blood flow to the baby? Am I right?

SPEAKER_01 12:33

Yeah, as far as I'm concerned. Okay. Um yes, it can cause renal problems in the in uh in fetus and it can affect blood flow across the placenta. Yeah.

SPEAKER_02 12:40

And it can do something to the heart as well, can't it, I think, potentially.

SPEAKER_01 12:44

Um why are you exposing my lack of knowledge? Yeah. Um but no, you're right. So but it's something that we avoid.

SPEAKER_02 12:51

Yeah, absolutely. Okay.

SPEAKER_01 12:53

So you're gonna get pain relief, yeah.

SPEAKER_02 12:56

Oh so I'm gonna give some antibiotics because I've got a CRP, I've got consolidation, and I've got some fluid. So there's definitely some inflammation there. Now the question is given her pain and the fluid, do I need to rule out a PE?

SPEAKER_01 13:16

Um, okay, first things first, which antibiotics are you gonna give us?

SPEAKER_02 13:21

Okay, so again, we're limited in pregnancy for what antibiotics we can give, but I know that amoxicillin is safe in pregnancy. So I'd probably go for because I'm treating a community-quired pneumonia amoxicillin, 500 milligrams CDS.

SPEAKER_01 13:36

So your plan is analgesia, uhmoxicillin orally.

SPEAKER_00 13:40

Yeah.

SPEAKER_01 13:40

Um, and now you're gonna scratch your head a little bit about whether or not we stop uh in terms of investigating and thinking whether we have our diagnosis.

SPEAKER_00 13:48

Yeah. Okay.

SPEAKER_01 13:49

And where do you sit with that? What would you what would you have done?

SPEAKER_02 13:55

Oh, this is a really difficult one because I think I'm overthinking it now.

SPEAKER_01 14:01

Talk me through what's your thinking process. Why is struggling?

SPEAKER_02 14:04

So I'm struggling because you said the very first sentence you said was 14 weeks pregnant, left pleuritic chest pain. This is a pulmonary embolism until proven otherwise. Have I now gathered enough information that's proven me otherwise? Or have I fallen prey to anchoring bias and anchored onto that first piece of information that you've given me and then completely gone down that PE route, which has, I guess, potentially stopped me from thinking of anything else, but also I'm very conscious that I can't miss a PE as well. Yes.

SPEAKER_01 14:46

So just to be clear, PE is the leading cause of maternal. Absolutely. We cannot afford to get this wrong. On the other hand, you've made a diagnosis which satisfies the presentation and the clinical picture. And you've made it based on um uh more than one modality. You've seen it on imaging, you've seen the inflammatory response on the blood test. It would explain the bit of pleural fluid, the uh the there's a bit of pleuritis there. You you have actually made a diagnosis.

SPEAKER_02 15:16

The only thing that's a bit weird is the normal blood tests. So, apart from the CRP of 81, which you can get potentially in pregnancy, everything else is normal. Now, if somebody's got a pneumonia, I would have thought that there would be some pyrexia and some inflammatory response. So would the some white cell count, some neutrophilia, which we don't have. Oh, flu? Have you done a flu flu swab?

SPEAKER_01 15:41

That's a really good thought. That was part of the post-8 water and plan, flu swab and cobe swap, and they both came back negative. That's a good thought.

SPEAKER_02 15:50

I mean, given my new famous skills, I could almost put an I could put a probe on and see what's I don't know. This is what am I gonna do? Am I gonna discharge or am I going to crunch time? Do you know what I could do? This is crazy.

SPEAKER_01 16:08

Yeah.

SPEAKER_02 16:09

With my new famous ultrasound skills, I can actually do DVT scans now, so I can have a look for any DVTs in the lower lips.

SPEAKER_01 16:17

Okay. Uh her legs are not swollen. But uh you can you want to have a look anyway. Uh okay.

SPEAKER_02 16:24

Uh just because it's a new skill and it's like when you have a new toy. I feel like I need to Yeah, okay. I do know what, Ben, I'm now gonna do what we're gonna do. I'm gonna send her home.

unknown 16:38

Yes.

SPEAKER_02 16:40

I am going to uh safety net her, but I'm only going to send her home when she can breathe normally because the amount of pain that she's in, I want to make sure that her pain is controlled properly.

SPEAKER_01 16:51

And how are you gonna safety net her?

SPEAKER_02 16:54

So safety netwise, um, if the pain gets worse, if you become short of breath, uh if you start any cough, any um you feel like you've got palpitations, any coughing up bloods, please come back to hospital straight away.

SPEAKER_01 17:10

Okay. So you the red flags you're gonna give her, I sounded like were signs of pneumonia and respiratory distress.

SPEAKER_02 17:16

Yes.

SPEAKER_01 17:17

Yeah.

SPEAKER_02 17:18

And I guess I'm thinking about a P as well. So if she becomes more short of breath, the pain gets worse, uh, she feels dizzy. So when she starts to um exercise or or walk on exertion, does the does she become more short of breath? So decreased exercise tolerance.

SPEAKER_01 17:36

Okay. So worsening breathlessness.

SPEAKER_02 17:38

Yeah.

SPEAKER_01 17:39

Now, what's really interesting is your plan is identical to the letter of the plan made by the clinician you saw on that day, which was we have a diagnosis um of an infection, uh pneumonia process. I don't think we have enough reason to justify proceeding to cross-sectional imaging at this point. I don't think the risk-benefit ratio favors that direction. I think home with amoxicillin and a bit of oromorph That's weird.

SPEAKER_02 18:08

Same plan.

SPEAKER_01 18:09

And if your symptoms were to worsen, here is uh how you access our safety net um uh safety net phone number that we have, you can ring on a daily basis, you've just been discharged, or you can come back to ambulatory care part of um Esteg. Exactly the same plan. How interesting. And I think that's an extremely reasonable plan. But we don't want to go over over-diagnosing people. End of episode. Bye, and thank you for listening. Of course, there's a little postscript. Two days later, she represents to ambulatory care, where I meet her for the first time. Or rather, um, one of the registrars I was working with met her, but I was the consultant sitting in that day. And she went and saw her. And the reason this woman came back to ambulatory care is she was adherent with all the medications we gave her. But this pleuritic pain is a nightmare. It's getting so bad. I'm like clutching my chest, I'm holding hot water bottles on it, but I it's like the worst stitch I ever had, and I can't get comfortable with it. It's so painful. Breathing was okay, actually, and there was no other clinical change in any of her status. She had leg didn't swell up, she didn't become hypoxical breathless. It was just the pain. It was just the pain. Um, and the registrar came and spoke to me and said, Look, what do you think about this? We we're still in the early doors, 40 hours of treatment. We could intensify the antibiotic treatment. She's still ephebrile. We have got a working diagnosis here, or do we do something else? And what would you do if your registrar came to you with that with that with that question?

SPEAKER_02 19:38

I'd go and see the patient. Okay. Um, primarily because um pregnant women, I always get a little bit twitchy because it's not my area of expertise or confidence. So um, and obviously knowing that they are a high risk of um clotting and sepsis, and that they are the leading killers of maternal causes of maternal death. So, second presentation with the pain, I want to know what is causing the pain. So I did some observations again just to make sure our oxygen levels are okay. Um, would I repeat the bloods? Probably not, because the bloods were only done two days ago, and I'm not sure it's gonna change my management plan. I want to scan this lady's lungs.

SPEAKER_01 20:27

Using what modality?

SPEAKER_02 20:29

Uh well, after I've obviously done my famous ultrasound scanner. I'll show you right now. Um you've got two options. She's had a chest x-ray, and then we need to think about are we going to do a VQ scan or we're going to do a CTPA? Now, I can't do a VQ scan because she has, because we've already got changes on the chest x-ray. Exactly. So therefore, a VQ scan is pointless because there's already going to be VQ mismatch.

SPEAKER_01 20:55

Exactly.

SPEAKER_02 20:56

So the only modality is a CTPA. Now, if you follow the green top guidelines from the um obs and gynee, um, then you must do first of all bilateral Dopplers of the legs. Because if you do bilateral Dopplers of the legs and it shows a clot, then you don't have to do a CTPA. If you do bilateral Dopplers and there's no clot, but you still think there's a clot in the lungs, then you do a CTPA.

SPEAKER_01 21:24

So just to be clear, what would your plan what's your plan now?

SPEAKER_02 21:27

I want to do scan both of her legs. So I could do that, but I can only rule one in. So if I find a clot when I do that, that's great. But if I don't find one, I'd have to send her for her departmental ultrasound doctor of both legs.

SPEAKER_01 21:42

Okay. Would you get that same day?

SPEAKER_02 21:45

Yeah, potentially. Yeah, absolutely. Also, now I'm starting to think about because I'm thinking clot, do I need to actually start treatment? Um Which with um heparin because low moleculate heprin because obviously we can't use a doak in pregnancy. So I'm gonna use one milligram per kilogram B D of an oxaparin and I'm going to do it according to her booking weight. And what booking weight is, is the weight that you are when you are eight or nine weeks pregnant when you first see the midwife. So it's not your weight at the time when you have um the presentation. Yeah.

SPEAKER_01 22:26

And if these Doppler scans were negative, yeah, then what?

SPEAKER_02 22:32

Would I see TPA or not?

SPEAKER_01 22:34

Yeah, I guess.

SPEAKER_02 22:36

To see TPA or not to see TPA. I'm gonna do a C TPA, Ben.

SPEAKER_01 22:43

Okay. Thank you. Um now he I'm glad we're doing this episode. I've got a little bit of uh CPD for you. The green top guidelines have changed. The Royal College now no longer recommends um bilateral Dopplers in the absence of clinical signs of DVT.

SPEAKER_00 23:00

Oh my god, what did this change? How embarrassing.

SPEAKER_01 23:02

I do not know. It changed within my consultant career because I remember when I was a Colour 5 consultant in 2017, bilateral Dopplers were considered the first line tests when diagnosed because there were no ionizing radiation. But now they say and if they have no signs of DVT in the leg, then you don't don't do it because the yield is microscopically low. And it doesn't actually it doesn't um prevent ionizing tests later on in the patient's journey. So that's actually out the window now. So I said there you go. Fact of the day. So I spoke to the registrar and I said, look, I I think we do have a diagnosis here. Why don't you speak to the patient about a CTPA, see what she thinks? I'm very happy to support a CTPA for them. We can get it done in an hour here in STEC. Well, and then we know uh the risks are very, very, very, very low. And I think I think sometimes we we get a bit more worried than we need to be about ionizing radiation. But what we have to hang on to is the fact that you need a healthy mother to have a healthy baby. We can't look at mum and baby as two separate entities and say, well, I think I'll protect baby, so let's not scan mum. That logic doesn't really stand up if mum has a diagnosis that it's going to uh cause morbidity or mortality because, of course, baby is is there with her. So I said, see what she was saying. And she came back and said, Look, I've spoken to the mum, she's really sensible, we're gonna do the CTPA. So we did the CTPA. Results came back an hour later. Bilateral pulmonary emboline uh to the lower lobes, burden higher on the left than the right. There's consolidation at the left base, which is likely a pulmonary infarct with the surrounding effusion, just like Dr. Berber said at the top of the uh the episode. So there we go. So this is a woman who presented with bilateral thromboembolic um disease, uh masquerading as a chest infection, and was initially treated still so reasonably, I think, with antibiotics that are much easier based on what was going on at the front door, but then came back because safety netting worked.

SPEAKER_00 25:01

Yeah.

SPEAKER_01 25:02

And she, yeah, and she and she got a scan and she got a diagnosis. And so the plan changed dramatically. So, of course, as you say, low moleculate heparin, she needs that for a whole pregnancy now. And six weeks after, yeah. She needs a planned C-section on a certain date so they can plan it around her anticoagulation doses. She needs to take low moleculate heparin in every subsequent pregnancy for the rest of her life because she's now high risk. She needs an echo to look for pomy hypertension, right heart strain. So uh, and follow up in the obstetric physician clinic, which um we have here. So a big, big changing plan from go home with antibiotics. Now, to me, when she came back and told me that result, that was too close. That was too close for comfort for me.

SPEAKER_00 25:49

I agree.

SPEAKER_01 25:50

Because I could have sent her home. I nearly did. Um, and I don't know what that would have happened. And it was just an example of a bullet whistling past your ear, just missing you. Um, and it and it and a nice symbol of sitting with with risk, and how sitting with risk is really the consultant's um core. And it's what we we have to do a lot. We can't diagnose everybody with everything. We can't C TPA, every pregnant woman who comes in with a twinge, as we said at the beginning, because that would be an absolute misuse of resources and would um expose the uh the population to harm and would actually overdiagnose things that never needed to be known about. But we cannot miss PEs in pregnant women because it's the leading cause of maternal death. And we have to do something about this. So that's my case. And to be fair, right at the top of the episode, you were talking about PEs. Um, and you talked about looking for consolidation and how that could still be a PE lurking underneath it. And remind me, Amy, how many diagnoses are patients allowed to have?

SPEAKER_02 27:01

They can have as many diseases as they damn well please.

SPEAKER_01 27:06

Thank you. So, of course, she can have a test in Fake Seppi if she likes. Um, but this case, I think, was a really big example for me about sort of the sliding doors moment of medicine where in another reality we said, look, keep going with antibiotics, safety net again, let's just see how you get on. She might not have come to any harm. But cases that like this, these mere misses, they do make my blood run cold a little bit.

SPEAKER_00 27:29

Yeah, yeah.

SPEAKER_01 27:30

But but what I'm paid to do after my my 20 years of experience of being a doctor is is be able to analyze risk um and sit with risk and explain risk. So explain it to myself, explain it to a patient, and explain it in the notes to anybody who cares to read it thereafter so they can understand my thought process at a time. And it's a skill which is a lifelong learning event.

SPEAKER_02 27:58

Would this change your practice? So if a patient came to you tomorrow with exactly the same symptoms, would you do a CTPA on admission?

SPEAKER_01 28:09

I've got to be completely honest. Yes, yeah, it has lowered my threshold.

SPEAKER_02 28:14

Yeah.

SPEAKER_01 28:14

I did a bit of reading after this, and I was like, am I being a bit silly about CTPAs? And and I did a bit of reading, and actually, the the radiation involved in a CTP and a VQ scan is well below the threshold is threshold that are associated with any kind of fetal or maternal harm. But because the because the uh radiation is there, that's why we have to to have these conversations and be careful. But there aren't actually any hard studies which have shown um increased short-term risk of breast cancer per CTPA in mothers um or in congenital malformations in children. But it's a theoretical risk, we feel beholden that we should be talking to patients about it. But I I think sometimes we're a bit I then own it, I am a bit fearful of radiation. You know, I see all these signs up in the x-ray saying, if you are pregnant, do not come in and tell a member of staff immediately. And that probably affects me as some blimminal. And we and we're talking we're taking consent from patients, we're asking, do you consent to a scan? So I it is a big deal in my in my mind. And of course, historically, you had to argue for a scan. You'd ring up radiology and they say, but but they're pregnant, you had to really state your case, you know, you know, your your case for for the for the judge and say, look, I know it. I will take the risk of this, but I think in this case, the woman needs a scan. And because you'd argue it and they were pushing back, um, yeah, you you do take, you hold some of the risks with you.

SPEAKER_02 29:40

Um, do you think because she was 14 weeks pregnant, which is quite early in pregnancy. Do you think that we can say that the cause of the embolite was due to pregnancy, or do you think this warrants investigation postpartum to look for other causes of hypercoagulability?

SPEAKER_01 29:58

That's a really good question. Um, did she uh have a chest infection to start with? And that plus the pregnancy led to a PE? Because we do know their pregnancy makes you five to ten times more likely to have a VTE, because a hypercoagulable state, or did she have their PE, which then led to a local inflammation and maybe a secondary infection, or maybe there was no infection at all? Um, but the the answer to your question is she will be followed up now by hematology, who will do the appropriate uh investigations for inherited thrombophilias, uh see if there's any risk of a recurrence.

SPEAKER_02 30:29

So that will happen anyway. And because this was her first pregnancy, she had no previous pregnancies. I guess that sort of puts anti-phospholipid syndrome as a cause a bit, a bit lower down the causative factors, because antiphospholipid syndrome, one of the problems women have with that is um sort of multiple miscarriages within early pregnancy because of the clots that form in the placenta. So actually, I guess it sort of doesn't rule it out but makes it sort of less likely. But it's certainly something that makes she's gonna have then isn't um postponed, isn't it? Okay.

SPEAKER_01 31:05

Yeah.

SPEAKER_02 31:05

Really interesting case, Ben.

SPEAKER_01 31:07

I was doing some reading as well. Uh have you ever heard of the years criteria?

SPEAKER_02 31:11

Do you know? I have heard of the year's criteria.

SPEAKER_01 31:14

I had not. Do you feel like you know well enough to talk about it now or not?

SPEAKER_02 31:18

No, sorry, it's it's a criteria that we utilize in pregnant women, and it's all to do with our uh favourite test in the world, the D-dimer. The D-dimer. So, do you want to elaborate on the year's criteria?

SPEAKER_01 31:32

It's it's something that um that I hadn't really come across before. Uh, of course, when we when we're doing risk stratification for VTE in the general population, we talk about Wells criteria. Um, and Wells criteria gives you a score, and then you can it guides you whether or not D-dimon might be useful or whether you need to go to imaging. And the tricky thing with pregnancy is the wells score gets really muddied up by some of the physiological changes of pregnancy. For example, there may be an uh uh elevated heart rate, pregnant women may get swollen legs, which were given like 9 million points on the well score, or the respiratory might be up a little bit. So actually, the well score becomes um less useful uh in pregnancy. And D-dimer, I've always been taught, is use less in pregnancy because D-dimer goes up in pregnancy. Um, however, the year's criteria, which was actually published in the New England Journal in 2019, says that there are some criteria you can use to risk stratify pregnant women. Um, and it's three clinical findings plus your D-dimer. And the clinical findings are number one, signs of a DVT, number two, hemoptasis. So far, so good. And then number three, oh, I'll this is why I was struggling with the world's criteria. Number three, PE is felt to be the most likely diagnosis. Oh these subjective criteria, I really struggle with reason I'm using your criteria because I don't know. Um, so I I uh I do struggle, but it says those are the three criteria you look at, and then you combine that with the pregnancy adjusted D-dymer threshold.

SPEAKER_00 33:06

Yeah, yeah.

SPEAKER_01 33:06

Uh, and then you can it gives you a score which can which calculates whether or not the your this pregnant uh patient is like to have APE or not. Um, I haven't used it before. It's something I'm gonna think about now going forward because the it was, and it was ratified actually in 2023 by the European Society of Cardiologists who said this should be our bread and butter now, and it actually avoids unnecessary scans from pregnant women. So I something I'm gonna try to use going forward years, it's just in Y E A R S uh criteria. Uh the other thing, yeah, as I mentioned before, is that Dopplers are uh now extremely limited in without any signs of a DVT. The number needed to scan to find um a clot is 43, and uh it it's it does just doesn't catch clots really, which is interesting because I remember learning that that was your first line test and it was up DVT. Yeah, yeah, yeah. Never got to do any scans because you just treat the DVT and NEP that might be there as well. So I thought that was super interesting as well.

SPEAKER_02 34:03

Yeah, thank you. Really good case. Highlighted my lack of up-to-date knowledge on the green top guidelines.

SPEAKER_00 34:11

Now we that's why I'm here for.

SPEAKER_02 34:12

Yeah, so I will read that. I I read about years, years ago. Um, so I will have a look at that. I think that's really helpful. Um interesting case. Very thought-provoking. And I think I'm gonna go away and reflect, do a lot of reflection on this and how I'm I'm in est tomorrow, which is ambulatory care. And I wonder if if this a patient similar to this comes in tomorrow, what would I do? Would I do this?

SPEAKER_01 34:38

Okay. Food for thought. Thank you so much for listening and playing along with me, Amy. And thank you, anyone, for playing along at home. Um, I hope you're enjoying these clinical cases and trying to work it out as we do as we go along. Maybe say a few things out loud if you feel brave enough. And maybe these little stories will help cement knowledge in your brain because it just makes it a bit more real. Um, and that's what we hope for here. Please do um leave us a rating or a comment wherever you're listening to this, iTunes, Spotify, or wherever, and uh tune in for further episodes of Home of Medicine podcast. Thank you for listening and goodbye.

SPEAKER_02 35:13

Goodbye.