Ep #154: Difficult Diagnoses: A Case Study in Critical Thinking with Courtney H

Welcome to the Real Deal Nurse Practitioner Club, the podcast for nurses who are ready to pass their boards and thrive in their careers as real deal nurse practitioners. I’m Anna and I’m the Director of Nursing Content at Blueprint Test Prep. Whether you’re deep in exam prep or stepping into practice, I’ve got you. It is time to become the confident, knowledgeable NP that you’re meant to be. Let’s dive in. 

Hey, hey everyone. Welcome back to another episode of the Real Deal Nurse Practitioner Club podcast. We have a really cool, unique episode today where we’re looking into some difficult diagnoses and not missing things. So, I have Courtney here. I’m going to let her introduce herself real fast.

Courtney: Hi there. I’m Courtney, and I’m the Senior Nurse Practitioner Content Editor at SMNP Reviews.

Anna: I’ve said this in previous episodes; she’s really our content guru. And she is going to help me dive into one of our favorite types of case studies for clinical practice, and that is the kind that keeps you on your toes. The ones that don’t follow the textbook and that require us to really have to plug into those critical thinking skills.

Courtney: And before anyone starts panicking, this episode is not meant to scare you away from clinical practice. We know that as students or early career clinicians, hearing about misdiagnoses or tricky cases can feel really intimidating, but that is not the goal here.

Anna: Yeah, and I really want to be clear. If you are here and you are studying for NP boards, stay focused on those typical textbook presentations, right? Boards are not trying to trick you with really obscure case scenarios. They are designed to make sure that you are a safe, competent, entry-level clinician.

Courtney: Right. What we’re doing here is about preparing you for what happens after the boards. In real-world practice, not every patient follows the script. It’s not about memorizing rare conditions; it’s really about training your brain to think critically and flexibly once you’re out in the field.

Anna: It’s a really big mindset shift, and it’s just that reminder that patient scenarios, they don’t line up perfectly with the textbook. As much as we want them to, they don’t. And our goal, it’s not to make you second guess yourself, but really we just want to help you develop the habit of slowing down, thinking things through, and approaching every patient as a unique individual. Because in clinical practice, typical doesn’t always mean universal.

So, with that said, let’s jump into today’s case scenario that we’re going to use. So let’s picture this. A 40-year-old patient presents to the clinic for a follow-up visit. They have a history of mild gastroesophageal reflux disease, or GERD, which is well controlled with famotidine as needed. They also have a history of breast cancer 5 years ago, which was treated with surgery and chemotherapy at that time. And now, they take tamoxifen daily. 

The patient reports eating a healthy diet and they routinely exercise. Over the past few months, they’ve noticed some progressive shortness of breath when hiking, which felt a little unusual for them, but otherwise, they’re feeling great.

Courtney: Yeah, so to recap, our patient has a history of GERD on PRN medication and a history of breast cancer on tamoxifen. While they report healthy lifestyle habits, due to that shortness of breath or dyspnea symptom, we perform a detailed review of systems, which is pretty unrevealing. 

So next step is the physical exam, which is also unremarkable, including normal lung sounds and vital signs. An ECG shows a normal sinus rhythm. Now, what do we do next?

So just from my experience as a preceptor, a lot of students would probably say, let’s order a chest x-ray, which isn’t necessarily unreasonable. But let’s pause and process for a second. If the patient’s exam is normal and their ECG is fine, what do we really expect to find out on that chest x-ray? This is a great time to zoom out and remember that dyspnea can be caused by all sorts of conditions.

Anna: Absolutely, right? Dyspnea can be respiratory, it can be cardiac, it can be hematologic, it can be metabolic, it could be medication-related. So this is that sign that we need to dig a little bit deeper. We can order some basic labs, CBC, CMP, maybe even thyroid labs to really cover the bases. But never forget to circle back to the patient’s history. Right? Their GERD is well controlled with PRN famotidine, so that’s likely unrelated. However, there is a big red flag in their history when it comes to shortness of breath. Do you remember what that is?

So this patient is a breast cancer survivor who’s currently taking tamoxifen. And a little quick recap on tamoxifen. It is a selective estrogen receptor modulator, or SERM, and it’s commonly used in the treatment and prevention of estrogen receptor-positive breast cancer. And so it works by blocking estrogen’s effects in breast tissue, which helps prevent cancer recurrence, which is great. But it acts like estrogen in other parts of the body too, like the liver and the bones.

Courtney: Yeah, so this estrogen agonist activity in the liver increases the production of clotting factors and decreases anticoagulant proteins. So the use of tamoxifen increases the risk of what? Blood clots, both deep vein thrombosis or DVT and pulmonary embolism or PE.

So now the wheels are turning. Could the cause of the patient’s symptoms be something clot-related? With that cancer history and tamoxifen use, we’re probably going to want another lab added to the orders today. Do you know what that is? A D-dimer.

So as a quick recap, a D-dimer is a lab test that measures tiny fragments of protein left behind when a clot dissolves in your body. So basically, when the body forms and then breaks down a clot, these fragments, the D-dimers, get released into the bloodstream.

Anna: Yep. So if that D-dimer is elevated, that tells us the body has been forming and breaking down clots somewhere. It doesn’t tell us where, it doesn’t tell us why, but it is a clue that clotting activity is happening. And it’s a really useful screening test, especially if you are suspecting something like a DVT or a PE. A negative D-dimer can help rule out clotting disorders in low-risk patients. Keep in mind though, a positive D-dimer does not confirm a clot by itself, but with this patient’s clinical picture, a positive result just means that we may need to go hunting for one with imaging.

Courtney: So this patient’s lab result and the basic labs look fine, but boom, the patient’s D-dimer is wildly positive, which leads us to a STAT CT angiogram. And sure enough, they have bilateral PEs. So what do we do next as primary care clinicians?

While the patient is technically hemodynamically stable, a PE is a medical emergency and can have dire consequences if not treated ASAP. So the safest course of action is to send the patient immediately to the emergency department. There, they’ll be started on anticoagulation right away to avoid a potentially dangerous outcome.

Anna: This is really our big takeaway from this episode. If we had tunnel-visioned on the usual suspects of shortness of breath and say, just investigated for exercise-induced bronchoconstriction or even an acute process like pneumonia, the patient’s diagnosis might have been delayed. Really, we could have even reasonably suspected that the patient’s symptoms might simply be related to altitude with hiking before we really dove into that history.

So this is where thorough history and physical assessment skills and good clinical reasoning really, really shine, and we never want to make assumptions, right? The patient’s shortness of breath was subtle. Their exam was unremarkable. But their history told the real story. So if we hadn’t taken the time to listen to our patient and take a thorough history, we might have missed that clue, the bigger picture, and a major diagnosis which could have had a really bad outcome.

Courtney: Yes, for sure. And remember, every clinical scenario is different. While this patient had mild symptoms, another patient with a PE may present with wildly overt symptoms like severe shortness of breath, tachypnea, tachycardia, or even pain with breathing. And so in that scenario, we would coordinate sending the patient straight to the emergency department the second they step foot in our clinic.

Anna: Yes, out as soon as possible. But now we can rest assured, right, our patient received prompt anticoagulation, they’re doing great. So now let’s just run through a quick recap of all the things that might cause dyspnea in a patient. So, as for respiratory causes, acute processes like pneumonia or chronic conditions like asthma, COPD, or even interstitial lung diseases can cause dyspnea or shortness of breath.

We’ve talked about cardiac causes, right? So always rule out ischemia, infarction, or conduction issues with an ECG. Heart failure, we know, is another big one that can cause shortness of breath. And if we suspected heart failure, we could order an echocardiogram or a particular lab test. What is that? Ask yourself as you listen. And that is our BNP lab. And like we learned with our patient today, always keep thromboembolic causes on your list of differentials and be on the lookout for those risk factors.

Courtney: Absolutely. And as for hematologic causes, all sorts of anemia can cause shortness of breath. Metabolic causes can include sepsis, acidosis, or even severe thyroid disorders. And always check the patient’s medication list, as even medications can play into dyspnea either directly or indirectly. 

For example, Brilinta is a common oral antiplatelet agent that is a well-known culprit. A good chunk of patients experience mild to moderate dyspnea due to its effects on adenosine metabolism. Another one is beta-blockers, like propranolol or metoprolol, which can cause bronchoconstriction, especially in patients with asthma. Amiodarone, which is an anti-dysrhythmic drug, as well as certain chemotherapy agents can cause drug-induced lung injuries leading to progressive shortness of breath.

Anna: Yeah, and just remember, it’s not about memorizing every single cause. It’s about using our critical thinking skills and looking at each individual clinical picture. So just ask yourself, does this fit? And if something doesn’t line up, do not be afraid to expand your differential list. And always, always trust your gut. At the end of the day, our job is not to check boxes. We need to be giving our best effort to really look at the human sitting in front of us and do the best that we can for them.

Courtney: Couldn’t have said it better myself.

Anna: I think that wraps up this episode. Make sure you are following us on Instagram @SMNPreviewsOfficial. And join us in our next episodes. We have a little mini episode coming up about some frequently asked questions related to doing practice questions. And then we’ll get into a couple studying and holiday related episodes. But we’ll see you next time.

Thanks for listening to another episode of the Real Deal Nurse Practitioner Club. If you want more information  about the different types of support that we offer to students and new nurse practitioners, you can visit npreviews, with an S, dot com. We’ll see you next week.