Smart Inhaler Parameters for Identifying Clinical Worsening in COPD, Leading Up to an Exacerbation: A Pilot Study

Background Acute Exacerbations of Chronic Obstructive Pulmonary Disease (AECOPD) drive disease progression and morbidity. Early prediction could enable timely intervention and thereby potentially limit the severity of the AECOPD and shorten its course. Smart inhalers measure inhalation parameters that may detect physiological changes preceding AECOPDs.Objective To explore whether changes in inhalation parameters (inhalation duration, Peak Inspiratory Flow (PIF), inhalation volume) as measured by a smart inhaler (RS01XTM) can identify clinical worsening leading up to an exacerbation within 14 days preceding an AECOPD.Methods This single-centre observational pilot study included nine COPD patients using maintenance therapy (LAMA/LABA ± ICS) with the RS01XTM inhaler for six months. AECOPD were defined based on daily symptom diary data. Trends in inhalation parameters during the 14-day pre-AECOPD window were compared with 14-day control periods without AECOPD using descriptive statistics, visual inspection, slope calculations, and exploratory generalised estimating equations (GEE).Results During the follow-up period, five AECOPDs occurred in three patients. While PIF (p = .007) showed a clear decline preceding AECOPD, inhalation duration (p = .712) and volume (p = .215) remained stable prior to an AECOPD.Conclusion Inhalation parameters, particularly PIF, appear promising and may reflect physiological changes associated with AECOPD. However, their use as a standalone predictor is still too early. The heterogeneity of COPD and the explorative design of this study limit their current predictive utility within a 14-day window. Nevertheless, these findings suggest potential for future research, particularly when combined with clinical and contextual data to improve predictive accuracy.