Dr Daniel Howell Details the Current Types of Therapies for Effective COPD Management

Chronic obstructive pulmonary disease (COPD) presents a significant challenge for both patients and health care providers and discussions of effective management strategies took center stage at CHEST 2024 in Boston. Daniel Howell, MBBS, MSc, clinical assistant professor at NYU Grossman School of Medicine, was one of 4 speakers discussing current therapies for COPD. In an interview, he shared what the session covered, including the latest evidence surrounding inhaler therapy, the optimization of management through home oxygen therapy, and respiratory muscle training, both of which play crucial roles in improving patient outcomes.

This transcript was lightly edited for clarity.

Transcript

Can you provide an overview of the session you participated in "COPD: Making the Most Out of Current Therapies"?

Yeah, so this session was really trying to touch on various aspects of managing a patient with COPD. Firstly, we had a talk from Dr. [Sarah] Assaf from the University of New Mexico, and she touched on the data that go behind the use of triple therapy—that's with ICS [inhaled corticosteroid]/[long-acting β-agonist]/[long-acting muscarinic antagonist] combination inhalers.

This is an area that's been, I think, an area of focus because we have 2 bits of data to contend with. We have a reduction in moderate-to-severe exacerbations in those with COPD who have exacerbations. And then we also have an increased risk of pneumonia if you're using inhaled corticosteroids with COPD. So, for those patients not exacerbating, we tend to try to avoid the ICS. But in those who exacerbate, we tend to use it. But there's a little bit of uncertainty there: how do we look at the phenotype of the patient? Perhaps they have an inflammatory phenotype with high eosinophil counts in the blood. So, yes, she talked us through that.

Then Dr. Jerry Krishnan from the University of Illinois spoke to us regarding roflumilast and azithromycin. These are 2 medications that reduce the risk of exacerbations in COPD. And he talked a little bit about the data behind those 2 medications and drug selection. This is something that he's studying in his RELIANCE trial, which he told us all about.

Thirdly, Dr. [Nicola] Hanania from the Baylor School of Medicine spoke to us regarding home oxygen therapy and the data behind that. There is uncertainty with regard to the use in patients with exercise-only hypoxemia and some of the practical aspects around that.

Then lastly, I spoke regarding respiratory muscle training in COPD. This was something that I wanted to focus on because I think, as pulmonologists, we think a lot about the lungs, and we don't think about what's just outside them. And actually, the mechanics of breathing, so how we breathe, is something that I think we need to focus a little bit more on. You know, not all dyspnea is just impairment of lung function. So dyspnea is something that's felt in the brain, and therefore there are central mechanisms that drive dyspnea. We have afferent fibers from the rib cage projecting into our sensory cortex that can drive dysthymia, the carbon dioxide chemoreceptors in the brain.

But also, if we think about the rib cage itself, and what happens with the COPD patient, both at rest and then worsens during exercise is that, because they have an increased expiratory lung volume, as they exercise, they are breathing closer and closer to their total lung capacity within a reduced inspiratory reserve volume, and that means that they have to work harder, right? So, the amount of pressure that they have to generate in order to get their desired tidal volume is a greater amount of pressure, a greater workload that the muscles are having to do, and this can therefore drive dyspnea.

So, respiratory muscle training is a way that can help improve that mismatch between the ventilator requirements and the strength of the muscles to meet those requirements, given the physiology that I just described. We have respiratory muscle training as a group, and then we have inspiratory muscle training and expiratory muscle training. In the COPD space, inspiratory muscle training is what's been studied most, and we have a number of different devices available for that.

A threshold device requires a patient to overcome the load that you set a certain pressure in order to generate flow. It's able to precisely determine what the load is of the patient that they're having to overcome like this are setting the pressure resistive training devices. They basically work by having a smaller and smaller orifice through which you have to generate your flow that does depend on the work of the patient, right? And how much effort they put into it, their inspiratory flow, which is related to resistance. That can be a little bit more difficult...when something's effort-dependent, it can be a little bit harder to know what the patient is doing. But still, certainly something that there is a role for and you know, the isocapnic hyperpnea device is there something that we don't really tend to use just because it's a lot more effort for the patient.