Impulse oscillometry for detection of small airway dysfunction in subjects with chronic respiratory symptoms and preserved pulmonary function

• Published in: Respiratory research Vol. 22; no. 1; pp. 68 - 10
• Main Authors: Li, Liang-Yuan, Yan, Tian-Sheng, Yang, Jing, Li, Yu-Qi, Fu, Lin-Xi, Lan, Lan, Liang, Bin-Miao, Wang, Mao-Yun, Luo, Feng-Ming
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 24.02.2021; BioMed Central; BMC
• Subjects: Adult; Airway obstruction (Medicine); Airway Resistance - physiology; Asthma; Asthma - diagnosis; Asthma - physiopathology; Chronic obstructive pulmonary disease; Correlation analysis; Demographics; Diagnosis; Dyspnea; Female; Forced Expiratory Volume - physiology; Humans; Impulse oscillometry; Lung - physiopathology; Lung diseases; Male; Methods; Oscillometry - methods; Parameters; Preserved pulmonary function; Pulmonary Disease, Chronic Obstructive - diagnosis; Pulmonary Disease, Chronic Obstructive - physiopathology; Pulmonary function tests; Pulmonary functions; Pulmonary manifestations of general diseases; Questionnaires; Reproducibility of Results; Respiration; Respiratory function; Respiratory Function Tests; Respiratory tract; Risk factors; ROC Curve; Sensitivity; Signs and symptoms; Small airway dysfunction; Spirometry; Sputum; China; Spirometry; Preserved pulmonary function; Small airway dysfunction; Impulse oscillometry
• ISSN: 1465-993X; 1465-9921; 1465-993X
• DOI: 10.1186/s12931-021-01662-7

Subjects with chronic respiratory symptoms and preserved pulmonary function (PPF) may have small airway dysfunction (SAD). As the most common means to detect SAD, spirometry needs good cooperation and its reliability is controversial. Impulse oscillometry (IOS) may complete the deficiency of spirometry and have higher sensitivity. We aimed to explore the diagnostic value of IOS to detect SAD in symptomatic subjects with PPF. The evaluation of symptoms, spirometry and IOS results in 209 subjects with chronic respiratory symptoms and PPF were assessed. ROC curves of IOS to detect SAD were analyzed. 209 subjects with chronic respiratory symptoms and PPF were included. Subjects who reported sputum had higher R5-R20 and Fres than those who didn't. Subjects with dyspnea had higher R5, R5-R20 and AX than those without. CAT and mMRC scores correlated better with IOS parameters than with spirometry. R5, R5-R20, AX and Fres in subjects with SAD (n = 42) significantly increased compared to those without. Cutoff values for IOS parameters to detect SAD were 0.30 kPa/L s for R5, 0.015 kPa/L s for R5-R20, 0.30 kPa/L for AX and 11.23 Hz for Fres. Fres has the largest AUC (0.665, P = 0.001) among these parameters. Compared with spirometry, prevalence of SAD was higher when measured with IOS. R5 could detect the most SAD subjects with a prevalence of 60.77% and a sensitivity of 81% (AUC = 0.659, P = 0.002). IOS is more sensitive to detect SAD than spirometry in subjects with chronic respiratory symptoms and PPF, and it correlates better with symptoms. IOS could be an additional method for SAD detection in the early stage of diseases.