Comparative evaluation of expiratory airflow limitation between patients with COPD and BE using IOS.

Impulse oscillometry (IOS) allows evaluation of the compartmentalized resistance and reactance of the respiratory system, distinguishing central and peripheral obstruction. The IOS measurements are getting attention in the diagnosis and differentiation of chronic respiratory diseases. However, no data are available in the literature to differentiate between COPD and BE using IOS parameters. We aimed to evaluate the feasibility of IOS in the diagnosis of bronchiectasis non-cystic fibrosis (BE) in comparison to COPD. Whole breath, inspiration, expiration, and inspiratory-expiratory difference (Δ) were evaluated based on the IOS parameters: total resistance (R5), central airway resistance (R20), peripheral airway resistance (R5-R20), reactance (X5), reactance area (AX), and resonance frequency (Fres). Fifty-nine subjects (21 Healthy, 19 BE, and 19 COPD) participated in this study. It was observed a significant difference in the comparison of healthy and pulmonary disease groups (BE and COPD) for total breathing (R5-R20, X5, AX, and Fres), inspiratory phase (R5 and R5-R5), and expiratory phase (R5-R20 and X5). The comparison between BE and COPD groups showed significant difference in the expiratory phase for resistance at 5 and 20 Hz and, ΔR5 and ΔR20. The IOS evidenced an increase of R5, R20 and R5-R20 in patients with BE and COPD when compared to healthy subjects. Expiratory measures of IOS revealed increased airway resistance in COPD compared to BE patients who had similar FEV1 measured by spirometry, however, further studies are needed to confirm these differences.

Acute Effects of Oscillatory PEP and Thoracic Compression on Secretion Removal and Impedance of the Respiratory System in Non-Cystic Fibrosis Bronchiectasis.

BACKGROUND: Bronchiectasis is characterized by abnormal and permanent dilatation of the bronchi, caused mainly by the progression of inflammatory processes and loss of the ability to remove mucus. Techniques to clear the airways are essential for the treatment of these patients. In this study, we aimed to evaluate the acute effects of oscillatory PEP and thoracic compression on both the clearance of secretions and impedance of airways in subjects with bronchiectasis. METHODS: This was a randomized crossover single-blinded study that involved both subjects with bronchiectasis and healthy subjects evaluated by using an impulse oscillometry system, which assessed resistance at 5 Hz and resistance 20 Hz, reactance at 5 Hz, reactance area, and resonant frequency, before, after, and 30 min after oscillatory PEP, chest compression, or control sessions. Dry and total weights, adhesiveness, purulence of the expectorated secretions, the dyspnea scale score, the acceptability and tolerance scale score, pulse oximetry, and difficulty in expectoration were also assessed. RESULTS: The dry and total weights of secretions were higher after the use of the oscillatory PEP technique than those in a control session (P = .005 and P = .039, respectively). In the bronchiectasis group, there was a decrease after oscillatory PEP in total airway resistance (P = .04), peripheral resistance (P = .005), and reactance area (P = .001). After compression, there was a decrease in peripheral resistance Hz (P = .001) and reactance area (P = .001). In the healthy group, there was an increase in resistance at 5 Hz (P = .02) after oscillatory PEP. There were no differences in acceptability and tolerance, dyspnea, and oxygen saturation. CONCLUSIONS: The oscillatory PEP technique was effective for the removal of secretions and in decreasing total and peripheral respiratory system resistance; thoracic compression had comparable positive effects on the peripheral resistance. Both techniques were safe and well tolerated by the subjects with bronchiectasis. ClinicalTrials.gov registration NCT02509637.).