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Research shows that digital inhalers equipped with remote monitoring capabilities may aid in predicting and identifying impending exacerbations of COPD.

Digital inhalers utilizing remote monitoring data may aid in predicting and identifying early or impending exacerbations of COPD, according to a study published in Chronic Obstructive Pulmonary Diseases: Journal of the COPD Foundation.

Physician’s Weekly (PW) spoke with lead study author M. Bradley Drummond, MD, MHS, professor of medicine in the Division of Pulmonary Diseases and Critical Care Medicine at the University of North Carolina, to learn more about the study and its implications for patients with COPD.

PW: What inspired your study?

Dr. Drummond: We were motivated by a critical need in COPD care, namely the ability to detect COPD exacerbations before they become clinically apparent. Exacerbations often result in hospitalizations or long-term lung function decline, and existing remote monitoring tools fall short in capturing physiologic changes specific to lung function. We believed that digital inhalers presented a unique opportunity to capture real-time inhalation parameters, such as inspiratory flow or inhaled volume, which could potentially reflect early physiologic deterioration, possibly even days before symptoms were recognized. This inspired us to explore whether digital markers from inhalers could signal an impending exacerbation in everyday clinical settings.

Did your team design the inhaler or use an existing device?

We used the FDA-approved ProAir Digihaler, which has the capability to measure inspiratory flow and volume, time-to-peak inspiration, and albuterol use; however, its ability to predict COPD exacerbations had not been explored in a research setting.

What was your study design?

We conducted a 3-month, phase-4, open-label observational pilot study at two academic centers in North Carolina. We recruited 40 ambulatory patients with COPD who routinely used albuterol and had a history of recent exacerbations, replaced their usual rescue device with the ProAir Digihaler, and monitored them virtually. Participants also recorded daily symptom scores using a smartphone app and completed monthly telehealth visits. After 3 months, we analyzed how the inhaler metrics changed in the 14 days before a self-reported exacerbation of COPD.

Were the findings surprising?

The key finding was that several inhalation parameters—specifically inspiratory volume, inhalation duration, and time to peak flow—all decreased significantly up to 2 weeks before an exacerbation. There has been considerable interest in peak inspiratory flow itself because it’s a parameter that impacts the ability to use inhalers correctly, but that didn’t change substantially. Another interesting observation was the increase in rescue inhaler use, which we would expect during an exacerbation, but it occurred much later, around 48 hours prior to the event. It was surprising to see physiological changes measured by the inhaler preceding symptom escalation and increased medication use, because we had assumed that patients would feel these changes and use their rescue inhaler more frequently. It’s almost as if the physiology was changing before the patient became aware of the worsening symptoms. That highlighted a potential new window for early detection and prevention—if we could flag these events before the patient even knew they were happening.

If the patients weren’t using the inhaler, how was it recording this information?

They were using the inhaler at the regular tempo they had used before the exacerbation period. Within that 14-day window, we observed changes in the inhalation parameters; however, we didn’t see an increase in albuterol use until just 2 to 3 days before the actual exacerbation began. The physiology had been changing during the 10 days prior, but the patient didn’t notice it until 2 or 3 days before.

What do you hope clinicians take away from your study?

Digital inhalers are more than adherence trackers; they should be viewed as a potentially rich source of real-time physiologic data. They can objectively track subtle symptoms and respiratory function. They may provide early warning signs of exacerbation. Potentially, they could become an integral part of remote monitoring, flagging impending exacerbations, and prompting timely intervention.

Could those alerts integrate directly into electronic health records?

Yes. The Digihaler syncs with a smartphone app on the user’s phone and transmits data to a portal, so we could envision a patient receiving an automated prompt—“We detected that you’re using your albuterol more. Your breathing pattern has changed. Is there a chance you’re having an exacerbation? Should you contact your healthcare provider?”—or it could be referred directly to the physician, who would receive an alert on their electronic health record platform.

What advances are required to make that a reality?

Passive data capture is important because it’s challenging to get people to do more, especially when they’re not feeling well. The other challenge is separating the signal from the noise, because with COPD, there is variation in day-to-day symptoms—you have good days and bad days—the hard part is detecting which bad days are going to lead to really bad days. So, specificity is important to focus on and develop. Having the ability to measure dynamic physiologic changes and utilize rescue medication is an important link that we believe should be further developed. There’s a lot of collected data available from these devices, so we need to determine the right algorithm to generate a meaningful warning, not just an alert that doesn’t actually translate to a disease. Currently, we’re re-analyzing data from over 5,000 inhalation events, which presents a substantial amount of data to examine. That’s the next step.

What resources do you recommend for physicians interested in learning more about exacerbations of COPD?

Begin with the annually updated Global Initiative for Chronic Obstructive Lung Disease document, which serves as the primary resource for COPD, encompassing all aspects of the disease, including exacerbations. Journals such as CHEST, American Journal of Respiratory Critical Care Medicine, and the Journal of COPD publish regular research and guidelines. Conferences like the American Thoracic Society meeting and dedicated digital health conferences showcase cutting-edge research, and many large health systems offer clinical decision support tools within their electronic health system.

Do you have any words of encouragement to share with physicians treating patients with COPD?

The course of COPD is not one that has to be uncontrolled. There’s always been a nihilism about COPD—that you can’t control it, that people are just going to get sicker and sicker and ultimately succumb to the disease—but we have wonderful, powerful therapies that can reduce exacerbations. As this study shows, we’re developing new technologies to identify exacerbations earlier. I believe we should have great optimism that we can significantly improve the health and quality of life for our patients with COPD.