Forced Oscillation Technique and Small Airway Involvement in Chronic Hypersensitivity Pneumonitis.


Divisao de Pneumologia, Instituto do Coracao (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brazil. Electronic address: [Email]


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 5Hz 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.


Air trapping,Atrapamiento aéreo,Chronic hypersensitivity pneumonitis,Forced oscillation technique,Neumonitis por hipersensibilidad crónica,Pruebas de función pulmonar,Pulmonary function tests,Técnica de oscilación forzada,