Longitudinal changes in pulmonary function and respiratory impedance of rheumatoid arthritis.

The aim of this study was to examine long-term changes in pulmonary function and respiratory impedance (Zrs) as assessed by forced oscillation technique (FOT) of rheumatoid arthritis (RA)-related pulmonary disorders. Data of 42 RA patients who underwent pulmonary function tests and Zrs measurements at least twice at a >900-day interval were retrospectively reviewed. Zrs, respiratory resistance (Rrs) and reactance (Xrs), were measured as a function of oscillatory frequency from 4 to 36 Hz.

Responsiveness to bronchodilator procaterol in COPD as assessed by forced oscillation technique.

The aim of this retrospective study was to assess responses to a bronchodilator by forced oscillation technique (FOT) and to relate the results of respiratory impedance (Zrs) to spirometric parameters in patients with chronic obstructive pulmonary disease (COPD). Zrs was measured as a function of frequency from 4 to 36Hz before and after inhalation of procaterol, a short-acting β-agonist (n=60). Respiratory resistance (Rrs) and reactance (Xrs) were significantly frequency-dependent, and inspiratory and expiratory phases were different both before and after procaterol inhalation.

Respiratory mechanics measured by forced oscillation technique in rheumatoid arthritis-related pulmonary abnormalities: frequency-dependence, heterogeneity and effects of smoking.

Rheumatoid arthritis (RA)-related pulmonary disorders specifically airway abnormalities and interstitial pneumonia (IP) are important extra-articular manifestations. The forced oscillation technique (FOT) is a useful method to assess respiratory impedance, respiratory resistance (Rrs) and reactance (Xrs), at different oscillatory frequencies during tidal breathing. The aim of this study was to characterize the respiratory mechanics of patients with RA and to relate them to parameters of the pulmonary function test and findings of chest CT images.

Influence of cheek support on respiratory impedance measured by forced oscillation technique.

The forced oscillation technique (FOT) is a useful tool to assess respiratory resistance and reactance during tidal breathing in patients with respiratory diseases, specifically asthma and chronic obstructive pulmonary disease. Although the FOT has been clinically used, results of respiratory impedance can be affected by various factors such as upper airway artifact. We investigated the effects of cheek support on respiratory resistance and reactance measured by a commercially available FOT equipment MostGraph-01.