Changes in tidal breathing biomarkers as indicators of treatment response in AECOPD patients in an acute care setting

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a complication of COPD that typically necessitates intensified treatment and hospitalization. It is linked to higher morbidity, mortality and healthcare spending. Assessment of therapy response for AECOPD is difficult due to the variability of symptoms and limitations in current measures. Hence, there is a need for new biomarkers to aid in the management of AECOPD in acute care settings. Fifteen hospitalized AECOPD patients (GOLD 3–4) were enrolled in this study. Treatment response was assessed daily through clinical evaluations and by monitoring tidal breathing biomarkers (respiratory rate [RR], expiratory time [Tex], inspiratory time [Tin], expiratory pause [Trst], total breath time [Ttot]), using a novel, wearable nanosensor-based device (SenseGuard™). Patients who showed significant clinical improvement had substantial changes in ΔTex/Ttot (+14%), ΔTrst/Ttot (−18%), and ΔTin/Tex (+0.09), whereas patients who showed mild or no clinical improvement had smaller changes (+5%, +3%, and −0.03, respectively). Linear regression between change in physician's assessment score and the median change in tidal breathing parameters was significant for Tin/Tex (R2 ​= ​0.449, ∗p ​= ​0.017), Tex/Ttot (R2 ​= ​0.556, ∗p ​= ​0.005) and Trst/Ttot (R2 ​= ​0.446, ∗p ​= ​0.018), while no significant regression was observed for RR, Tin/(Trst ​+ ​Tex) and Tin/Ttot. Our study demonstrates the potential of the SenseGuard™ to monitor treatment response in AECOPD patients by measuring changes in tidal breathing biomarkers, which were shown to be associated with significant changes in the patients' respiratory condition as evaluated by physicians. However, further large-scale clinical studies are needed to confirm these findings.