This transcript has been edited for clarity. For more episodes, download the Medscape app or subscribe to the podcast on Apple Podcasts, Spotify, or your preferred podcast provider.
Leah J. Witt, MD: Hello. I'm Dr Leah Witt. Welcome to season 1 of the Medscape InDiscussion: Chronic Obstructive Pulmonary Disease (COPD) podcast series. Today, we're talking about the diagnosis and management of COPD.
COPD is the most common chronic lung disease in the world. Global prevalence is about 10%, and its prevalence is only expected to rise because the population is aging and risk factors like tobacco and biomass pollution persist. Among adults aged 50 or over, COPD is one of the top three causes of death worldwide, with higher death rates in low- and middle-income countries.
Today, I'm delighted to welcome expert guest Dr Stephanie Christenson. Dr Christenson is an associate professor at the University of California, San Francisco, in the Division of Pulmonary Critical Care, Allergy, and Sleep Medicine. She cares for patients in the outpatient general pulmonary clinic and attends on the inpatient pulmonary consult service. She is a COPD and asthma clinical and genomics researcher, focused on understanding the heterogeneity of airway disease, which will be the topic of today's discussion. Finally, she and I both hail from Wisconsin, so I'm really excited to kick off our first podcast episode with a fellow Midwesterner. Welcome to the Medscape InDiscussion podcast, Stephanie.
Stephanie A. Christenson, MD, MAS: Thank you, Leah.
Witt: I wanted to start the podcast episode by getting to know you a little bit outside of medicine. We know that you're an expert researcher and clinician, but what is on your mind outside of medicine, like a hobby, piece of pop culture, or something like that?
Christenson: I've got a big yard, so I usually do a lot of gardening, but California has had a lot of storms, so my gardening has devolved into picking up a lot of sticks and throwing them for the dog. That's been what I've been doing outside of medicine. What about you?
Witt: Baking is my number one hobby, and I am trying to perfect my royal icing technique. The real way is to use egg whites, which just sounds kind of gross to use raw egg whites in icing.
I've been using egg replacement and meringue powder, but I tried to have an elaborate decoration this weekend. Unfortunately, it all just kind of like melted together like a snowman.
Christenson: Did it still taste good?
Witt: It still tasted good.
Let's dive in. We have a case, and I want to talk today about your approach to diagnosing COPD and your initial steps in management. Let's start with the case, and then I'll dive into my questions.
This is a case based on an amalgamation of patients that we've seen in clinical practice, no one in particular. I'm calling this patient Mr Rivera. He's a 78-year-old man who has a chronic productive cough. He comes to be evaluated in the pulmonary clinic. He was recently hospitalized for influenza. He says that every year for the past 5 years when he gets a viral illness, he has a really prolonged cough.
He's sick longer than his family members, and he often gets antibiotics. He started smoking when he was 20 and smoked one pack a day for 55 years. He stopped 3 years ago. He lives with his wife. He used to do the grocery shopping, but she had to take over the grocery shopping because he becomes too short of breath when carrying the groceries. His other medical problems include cardiovascular disease, He had a myocardial infarction (MI) 10 years ago, and he has diabetes.
I think this is a typical patient that we see in the pulmonary clinic. How would you approach this patient? What are the things on your mind?
Christenson: I think you're right. To me, this sounds like a typical patient. We see them after being hospitalized for influenza. Whether that's actually an influenza pneumonia, or potentially compounded by COPD exacerbation in a patient with undiagnosed COPD, is potentially what we're looking into.
I'll stick to the COPD diagnostic criteria because that's what we're focusing on today. This is a pulmonologist office, so I'm going to be getting spirometry first. With COPD, the diagnostic criteria, at least currently, are that you need to have a fixed defect. Whether you're using a 70% Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria or lower limit of normal, based on how some people do it, it's a little bit of a debate. But if we're seeing a fixed defect, that is where I'm starting to think about a COPD diagnosis. That's how I would start.
Then you'd potentially go on to symptoms and exacerbations. That's going to help me figure out how I'm going to classify and treat the patient. Is that how you would approach this patient as well?
Witt: Yes, definitely. I feel like his history is screaming COPD, but I would also be thinking, is there anything else? You want to be confident in the diagnosis with spirometry. He's got a cardiovascular history. That's where the exam helps. I'm thinking about if he is he in heart failure, things like that. The history here was pretty straightforward for COPD.
The diagnostic criteria for COPD are interesting to me. The GOLD is very clear. They want there to be a reduced ratio below 0.7 post-bronchodilator. I think their rationale for that is interesting because they want the spirometry to be available and easy to interpret no matter the resources available.
Spirometry is a pretty cheap and easy thing to get no matter where you are. But if we start looking at the Global Lung Function Initiative (GLI) and at the equations that use these scores and lower limit of normal, that might help a little bit with the underdiagnosis and overdiagnosis problem. We see overdiagnosis in older populations and underdiagnosis in younger populations. That would be probably harder to get if you're in a lower-resource setting.
Christenson: Overall, COPD is very underdiagnosed. I'm going to be thinking, Do you need treatment? especially in a patient like this, where they're potentially having exacerbations and a lot of symptoms. Even if I'm considering if this case is on the cusp, I'm trying to make sure that I'm using the lower limit of normal if I'm using the fixed ratio. That's because exacerbations have such bad outcomes. If I do see a fixed effect, I'm considering, would this patient benefit from particularly our inhaled therapies? We want to try to prevent future events.
Witt: Are you ordering imaging on the first visit? It sounds like maybe the patient is out of his exacerbation or his influenza, whether or not it was a pneumonia. Are you ordering imaging on the first visit and if so, what are you doing?
Christenson: Not necessarily. Oftentimes these patients meet criteria for getting low-dose CT. Sometimes that information can be helpful. If I see emphysema, particularly in patients where they're a little bit borderline for a COPD diagnosis, maybe they've got some long-standing asthma, how should I go about treating that patient? Is the inhaled corticosteroid (ICS) more important, or are the long-acting beta-agonist (LABA) or long-acting antimuscarinic (LAMA) therapies more important? I might be thinking about some of those nuances.
If I'm seeing somebody who has a fixed defect, I may not need that CT scan. However, I may be doing CT anyway for cancer screening. What about you?
Witt: We also know he was just hospitalized. Maybe he already has something that we can look at. Let's continue the case, and then we can decide if our diagnosis is done.
We decided to order spirometry with a diffusing capacity. His forced expiratory volume in 1 second (FEV1) is 60% predicted. His postbronchodilator FEV1 to forced vital capacity ratio is 65%, and then his diffusing capacity is 48% predicted. What do you think of those pulmonary function tests (PFTs), and is there anything else you would do before you move to your management?
Christenson: We've got a fixed effect, so we've got COPD. I would probably be looking at the flow volume loops as well, just to see whether those look curvilinear. Are there nuances there?
Looking at the diffusing capacity of the lungs for carbon monoxide (DLCO), that could certainly be down because of emphysema. That's maybe another piece of the puzzle. Because he has cardiovascular disease, I may be interested in seeing what the CT scan looks like too. I would like to have an explanation for that low DLCO. Is it emphysema, or is it potentially something else given his other comorbidities? I would want to check to make sure we're not missing something. He was just recently hospitalized, so blood clots are important.
If I don't see emphysema on that CT scan, then it might make for me to see that low DLCO as a red flag. Is there something else going on? Those PFTs would certainly all be very consistent with a COPD diagnosis, but as we're rounding out the patient and thinking about him as a whole, we're ensuring that we're not missing something.
Witt: I wanted to ask you about disease heterogeneity, which is one of the things in which you're an expert. What does "disease heterogeneity mean?" How does that affect how you parse out the disease subtype and management?
Christenson: I think of disease heterogeneity in a couple of different ways. One is clinical heterogeneity. The GOLD report has gotten at that with the treatable traits algorithm, where we think about symptoms and we think about exacerbations.
I'm also thinking about clinical heterogeneity in other forms. For example, some patients are frailer and more prone to things like pneumonia. This might make me think differently about how I treat them. Some patients have cardiovascular disease. I want to make sure that I'm thinking about other systemic diseases like cardiovascular disease and sleep apnea. Depression and anxiety are huge comorbidities.
I might be thinking about clinical heterogeneity, as well as heterogeneity of the disease itself. This includes exacerbations and symptoms of emphysema. For example, emphysema, chronic bronchitis, the "pink puffer"/"blue bloater" that we normally think of — there's actually a lot more clinical heterogeneity beyond that.
I also may think of biological heterogeneity. I do my research on this. In terms of biological heterogeneity, we've started thinking about eosinophils as being a marker of a patient who may have more type 2 or eosinophilic inflammation. That patient might benefit from other therapies. Right now, that therapy would be inhaled steroids. I think of it clinically and biologically. How might a patient benefit from our therapies, based on that heterogeneity?
Witt: I love that approach. I never thought of disease heterogeneity as including the comorbidities. That's a really interesting approach and certainly affects your choice of medications, even outside of comorbid asthma, for example.
Christenson: We're thinking of these patients as a whole and realizing what we can do for them with some of our medications, but also what we can do for them by treating some of their other comorbidities or helping with their exercise capacity, et cetera. This may help a lot more than just throwing an extra inhaler at them. We want to make sure that we're thinking of them as a whole person.
Witt: On the first visit, or after you got the PFTs, you're sure it's COPD, are you ordering serum lab values or an eosinophil count? Or maybe you're just doing a look back to see whether he's had an eosinophil count or any other blood work?
Christenson: I usually do look at eosinophils, particularly in a patient like this who was possibly hospitalized for an exacerbation; hospitalized exacerbations have a much higher mortality rate. I call them the "heart attack of the lung." I'm certainly going to check an eosinophil count in this type of patient.
I do check it in a lot of my patients. The reason for that is that if it's high, I'm going to want to think about triple therapy, meaning keeping them on inhaled steroids, a LABA, and a LAMA, even if the eosinophil count is low.
I'm not too concerned about keeping them on inhaled steroids. I will probably keep the patient on the steroids because some secondary analysis data show potential improved mortality with triple therapy compared with the dual therapies. However, certainly if you have a high eosinophil count, I'm really thinking about it.
Witt: And I think we would call him stage E. That just changed in the GOLD guidelines. That used to be C and D. Do you know why they did that?
Christenson: First of all, although I certainly see patients in my practice who are exacerbation prone and have no symptoms, it's not a huge group. Patients are usually symptomatic, or they're symptomatic and exacerbation-prone.
There are some people who are fine and then suddenly have an exacerbation, but it's not common. Either way, the outcomes with exacerbations are bad enough that symptoms or no symptoms, we want to ensure that you're on the maximal therapy to prevent future exacerbations.
It's based on the history. We're just trying to change it to three categories. You either have exacerbations or you don't. If you don't have exacerbations, do you have symptoms? If not, then you're in that first category.
Witt: Got it. So, this patient would maybe get triple therapy, depending on his eosinophils or how sick he is. The other option would be a LAMA-LABA combination.
Christenson: Yes, that's how I would treat him. Like I said, it's a little nuanced with the inhaled corticosteroid, LABA, and LAMA, whether you definitely want to keep that on vs LABA-LAMA. The guidelines currently suggest keeping him on if he has a high eosinophil count and potentially taking him off of it if the count is low. I would probably keep him on triple therapy unless he was showing me that there was a good reason to take them off. For example, if he's getting bacterial pneumonia or is frail and I'm very worried about keeping an inhaled steroid on.
Witt: When would you think about adjunctive therapy? I've started patients on azithromycin or roflumilast. What other therapies are you thinking about if he's still having exacerbations despite your best efforts?
Christenson: That's a very good question. The first thing I'm thinking about before I do any of those, and I know that you probably are thinking about this too, is whether he's adherent to the medications that he's currently on. How is his inhaler technique? Sometimes I'm checking it or having one of our respiratory therapists check it. There's a lot of ways you can get that wrong.
I'm also thinking about pulmonary rehab, because I do think that can be one of the most beneficial things that we can do. In subsets of people, I might use azithromycin or roflumilast.
In exacerbation-prone patients, I'm concerned about giving them a chronic antibiotic that they could become resistant to. Roflumilast can have a lot of gastrointestinal side effects. Not everybody tolerates it. I think the more patients you try some of these in, you do find a subset of people for whom it's incredibly helpful.
I encourage other providers to learn from us that it can drastically help some patients. But I'm not going to necessarily keep patients on it if it's not helping or if they're not feeling better from it and are still continuing to have bad symptoms and exacerbations.
Witt: You hit on something so important: medication adherence. And then there's technique issues and cost issues. We're going to dedicate a whole episode to this because I think that's the number one reason why a medication in COPD is not working: the cost. Maybe the patient hasn't hit their deductible, and they can't afford the $500 in January.
Christenson: Yes, it is so frustrating and so important.
Witt: You already talked a little bit about pulmonary rehab and managing comorbidities. How do you see your role as a pulmonologist in thinking about comorbidities? What do you feel is our role as pulmonologists?
Christenson: I'm certainly checking that box. When I see my patients, hopefully every time (although I must admit we don't have time every single time), we want to make sure that our patients are getting vaccinations. Otherwise, we need to be working as team players with the primary care physicians, cardiologists, and potentially psychiatrists and sleep experts to understand whether the patient is at increased risk for cardiovascular disease, depression, anxiety, obesity, or sleep apnea.
Some of the reasons that patients may not be doing well may be because of these comorbidities. Certainly, we know that the feeling of dyspnea is worse if you are also feeling depressed or anxious. Maybe some of those things are going to make depression and anxiety worse.
We want to work with our primary care physicians and other providers to ensure that those issues are addressed as well. That's how I think of myself as a COPD expert. We're thinking about that patient as a whole.
Witt: That is so important. As a geriatrician, I feel like this approach is so important for managing chronic diseases or chronic lung diseases.
That's all we have time for. Do you have any final key points that you want to leave our listeners with?
Christenson: What is so important to me in this discussion is thinking of these patients as a whole. First of all, knowing that there is a lot we can do for these patients to make them feel better, and for their symptoms to feel better. We also want to make sure that they understand that exacerbations are really bad for you and that a lot of what we do is preventive. We're going to try to prevent you from feeling worse or from potentially even dying, by using some of these therapies. The comorbidities, symptom control, and exacerbation control are really key pieces.
Witt: I'm taking away that you taught us that exacerbation is a heart attack of the lung, which I love. And that disease heterogeneity is more than just the biologic heterogeneity. We should think about an ICS, but also we're thinking about their comorbidities and heterogeneity. Thank you so much for that.
To summarize, today we talked to COPD expert Dr Christenson about pearls for diagnosis, special considerations with deciding which inhaler to use, and how we risk-stratify based on GOLD group and initial management. This was such a rich discussion. Thank you so much for joining. Please take a moment to download the Medscape app to listen and subscribe to this series and others. This is Dr Leah Witt, for Medscape InDiscussion: COPD.
Resources
Global Strategy for Prevention, Diagnosis and Management of COPD:2023
Global Lung Function Initiative Calculators for Spirometry, TLCO and Lung Volume
Tidal Flow-Volume Loop Enveloping at Rest in Advanced COPD
Treatable Traits in COPD — A Proposed Approach
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Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: COPD Case Study: Pearls for Diagnosis and Initial Management - Medscape - Mar 26, 2024.
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