Measurement of physiological recovery from exacerbation of chronic obstructive pulmonary disease using within-breath forced oscillometry.

Background: Within-breath reactance from forced oscillometry estimates resistance via its inspiratory component (X(rs,insp)) and flow limitation via its expiratory component (X(rs,exp)).

Aim: To assess whether reactance can detect recovery from an exacerbation of chronic obstructive pulmonary disease (COPD).

Method: 39 subjects with a COPD exacerbation were assessed on three occasions over 6 weeks using post-bronchodilator forced oscillometry, arterial blood gases, spirometry including inspiratory capacity, symptoms and health-related quality of life (HRQOL).

A longitudinal study of lung function in nonsmoking patients with rheumatoid arthritis.

Study Objective: s: Patients with rheumatoid arthritis (RA) have a high prevalence of pulmonary function test (PFT) abnormality, but the long-term significance of this is unknown. We performed a longitudinal study of pulmonary function in asymptomatic, nonsmoking patients with active RA requiring disease-modifying drugs. We looked for temporal change in lung function and characteristics that would predict subsequent development of PFT abnormality or respiratory symptoms.