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Forced Oscillation Technique and Small Airway Involvement in Chronic Hypersensitivity Pneumonitis
- Source :
- Archivos de Bronconeumología (English Edition). 55:519-525
- Publication Year :
- 2019
- Publisher :
- Elsevier BV, 2019.
-
Abstract
- Objective Hypersensitivity pneumonitis (HP) is an interstitial lung disease caused by the inhalation of specific organic antigens or low-molecular weight substances in genetically susceptible individuals. Although small airway involvement is prominent in patients with chronic HP, conventional pulmonary function tests (PFTs) are relatively insensitive to identify it. Thus, the authors aimed to evaluate resistance (R5) and reactance (X5) values at 5 Hz on inspiration, expiration, and whole breath, as well as small airway resistance (R5–19) values using a forced oscillation technique (FOT) in patients with chronic HP, and their responses after bronchodilator. In addition, R5 and X5 values according to the presence or absence of mosaic attenuation on computed tomography (CT) were compared. Methods PFTs with plethysmography, diffusing capacity of the lungs for carbon monoxide (DLCO) and FOT measurements were performed pre-bronchodilator and post-bronchodilator. High-resolution CT was performed at the same visit, and classified according to the presence or absence of mosaic attenuation. R5 and X5 values were then compared according to the presence or absence of mosaic attenuation on CT. Results Twenty-eight patients with chronic HP (57.1% female; mean age, 56 ± 11.5 years; mean forced vital capacity 57 ± 17% predicted) were evaluated. All patients had low X5 values, reflecting lower lung compliance, and only three (8%) demonstrated elevated R5 (whole-breath) values. No patients exhibited bronchodilator response in R5, X5 and R5–19 values. In patients who exhibited greater extension of mosaic attenuation (n = 11), R5 and X5 values could not discriminate those with a greater presence of these areas on CT. Conclusions The results suggest that FOT does not help to additionally characterise concomitant small airway involvement in patients with chronic fibrotic HP who demonstrate restrictive ventilatory pattern in conventional PFTs. Nevertheless, FOT appeared to better characterise decreased lung compliance due to fibrosis through X5. Bronchodilator therapy did not appear to induce an acute response in chronic HP patients with restrictive disease. The precise role of FOT in subacute HP and obstructive chronic HP, therefore, must be evaluated.
- Subjects :
- Male
Pulmonary and Respiratory Medicine
medicine.medical_specialty
Vital capacity
medicine.drug_class
Air trapping
Chronic hypersensitivity pneumonitis
Forced oscillation technique
Pulmonary function tests
Pulmonary compliance
Pulmonary function testing
03 medical and health sciences
0302 clinical medicine
Airway resistance
DLCO
Diffusing capacity
Internal medicine
Bronchodilator
medicine
Humans
Aged
business.industry
Airway Resistance
General Medicine
Middle Aged
medicine.disease
Respiratory Function Tests
030228 respiratory system
Chronic Disease
Cardiology
Female
business
Hypersensitivity pneumonitis
Alveolitis, Extrinsic Allergic
Subjects
Details
- ISSN :
- 15792129
- Volume :
- 55
- Database :
- OpenAIRE
- Journal :
- Archivos de Bronconeumología (English Edition)
- Accession number :
- edsair.doi.dedup.....6fcd08a16655c372c000a615d9f5a3ce