Respiratory Oscillometry and Functional Performance in Different COPD Phenotypes

Purpose: Chronic obstructive pulmonary disease (COPD) phenotypes may introduce different characteristics that need to be known to improve treatment.Respiratory oscillometry provides a detailed analysis and may offer insight into the pathophysiology of COPD.In this paper, we used this method to evaluate the differences in respiratory mechanics of COPD phenotypes. Patients and Methods:This study investigated a sample of 83 volunteers, being divided into control group (CG = 20), emphysema (n = 23), CB (n = 20) and asthma-COPD overlap syndrome (ACOS, n = 20).These analyses were performed before and after bronchodilator (BD) use.Functional capacity was evaluated using the Glittre-ADL test, handgrip strength and respiratory pressures.Results: Initially it was observed that oscillometry provided a detailed description of the COPD phenotypes, which was consistent with the involved pathophysiology.A correlation between oscillometry and functional capacity was observed (r=-0.541;p = 0.0001), particularly in the emphysema phenotype (r = -0.496,p = 0.031).BD response was different among the studied phenotypes.This resulted in an accurate discrimination of ACOS from CB area under the receiver operating curve (AUC) = 0.84 and emphysema (AUC = 0.82). Conclusion:These results offer evidence that oscillatory indices may enhance the comprehension and identification of COPD phenotypes, thereby potentially improving the support provided to these patients.