Digital inhalers that measure and record inhalation data and that can remotely monitor patients may help predict impending chronic obstructive pulmonary disease (COPD) exacerbations, that is, episodes when lung symptoms suddenly worsen.
That’s according to data from a Phase 4 observational pilot study (NCT05241288) that followed 40 COPD patients with poor lung function and recurrent exacerbations. In the two weeks before an exacerbation, the volume and duration of their inhalations fell while the use of inhalation medications rose, data showed.
“While this study examined a small group of participants, the remote monitoring data showed people experienced significant decreases in the amount of air they inhaled and how long that inhalation lasted in the approximately two weeks prior to experiencing an exacerbation,” M. Bradley Drummond, MD, the study’s principal investigator and a professor of medicine at the University of North Carolina, said in a press release from the COPD Foundation.
The findings were described in the study, “Use of a Digital Inhaler to Assess COPD Disease Variability and Identify Impending Acute COPD Exacerbations: A Pilot Study,” which was published in Chronic Obstructive Pulmonary Diseases: Journal of the COPD Foundation.
A chronic inflammatory disease of the lungs, COPD is marked by blocked airways and symptoms such as cough with mucus, wheezing, and shortness of breath. Exacerbations, or flare-ups, are common, with more than half of patients having at least one exacerbation within four years of their COPD diagnosis. They can persist for several days, accelerate the decline in lung function, reduce physical function and quality of life, and may require treatment or hospitalization.
While some research has evaluated the ability of digital inhalers to monitor treatment adherence or support correct technique, few studies have focused on “the use of digital inhalers that incorporate dynamic physiologic and inhaler medication use patterns to identify impending [COPD exacerbations],” the researchers wrote.
ProAir Digihaler, which became available in the U.S. in 2020, is a digital inhaler that delivers the bronchodilator albuterol to patients’ lungs, relaxing and opening the airways to make breathing easier. The device carries a sensor to detect and record various inhaler parameters, such as inhaler use and inhalation volume. Users can view the data on a companion app and share them with healthcare providers to monitor breathing metrics and evaluate the impact of treatment.
Predicting COPD exacerbations
In a pilot study, Drummond and his colleagues examined whether the ProAir Digihaler can help predict an impending COPD exacerbation. The researchers remotely enrolled 55 COPD patients with poor lung function and a history of two moderate or one severe exacerbation.
“This study was unique in that patients were enrolled remotely and used a novel version of the companion app that would ask about patient symptoms in response to triggers of worsening COPD status, based on their inhaler use and inhaler parameter data,” the researchers wrote.
The final analyses included 40 participants who had at least 30 days of Digihaler data and completed a one-month phone visit. Their mean age was 62.5, 48% were women, and all were smokers.
Over the three-month study, more than 9,600 inhalations were captured and 15 patients had 23 exacerbation events. Several parameters captured by the digital inhaler significantly worsened in the two weeks before an exacerbation.
Changes ahead of an exacerbation
The mean volume of inhalation dropped from 1.45 to 1.08 liters, representing a 25.2% decrease. Over time, the inhalation volume dropped between 14 and 10 days before an exacerbation, after which it stabilized until a week before an exacerbation. After that, there was a marked drop in inhalation volume leading up to an exacerbation.
There was also a decrease in the mean inhalation duration (1,876 to 1,492 milliseconds) and the mean time to maximum inhalation (500 to 376 milliseconds). The peak inspiratory flow, the maximum airflow achieved during a forced inhalation, remained relatively stable over the two weeks before an exacerbation.
Moreover, the mean number of daily albuterol inhalations steadily increased from 14 to five days before an exacerbation, followed by a slight decrease, then a rapid increase in the two days before an onset of one. The monthly medication use, as reported by patients during phone visits, matched the actual medication use captured by the inhaler.
“The results from this study suggest that an algorithm incorporating physiological changes may identify impending [COPD exacerbations] sooner than algorithms relying solely on increased rescue inhaler use,” the researchers wrote.
While the software and technical support for the Digihaler App were discontinued last year in the U.S., other digital inhalers can monitor medication use, the researchers said.
“These findings demonstrate the value of using digital inhaler data to monitor [medication] use and the potential to use digital inhaler data to help identify [COPD exacerbation] events prior to onset,” the researchers wrote.
“As these remote monitoring technologies get more advanced, we can help both patients and healthcare providers identify exacerbations earlier, which allows us to provide better exacerbation management and improve health outcomes,” Drummond said.
