Characterization of Lung Function Impairment in Adults with Bronchiectasis

BACKGROUND: Characteristics of lung function impairment in bronchiectasis is not fully understood. OBJECTIVES: To determine the factors associated with lung function impairment and to compare changes in spirometry during bronchiectasis exacerbation and convalescence (1 week following 14-day antibiotic therapy). METHODS: We recruited 142 patients with steady-state bronchiectasis, of whom 44 with acute exacerbations in the follow-up were included in subgroup analyses. Baseline measurements consisted of chest high-resolution computed tomography (HRCT), sputum volume, purulence and bacteriology, spirometry and diffusing capacity. Spirometry, but not diffusing capacity, was examined during acute exacerbations and convalescence. RESULTS: In the final multivariate models, having bronchiectasis symptoms for 10 years or greater (OR = 4.75, 95%CI: 1.46–15.43, P = 0.01), sputum culture positive for Pseudomonas aeruginosa (OR = 4.93, 95%CI: 1.52–15.94, P<0.01) and HRCT total score being 12 or greater (OR = 7.77, 95%CI: 3.21–18.79, P<0.01) were the major variables associated with FEV(1) being 50%pred or less; and the only variable associated with reduced D(L)CO was 4 or more bronchiectatic lobes (OR = 5.91, 95%CI: 2.20–17.23, P<0.01). Overall differences in FVC and FEV(1) during exacerbations and convalescence were significant (P<0.05), whereas changes in other spirometric parameters were less notable. This applied even when stratified by the magnitude of FEV(1) and D(L)CO reduction at baseline. CONCLUSION: Significant lung function impairment should raise alert of chest HRCT abnormality and sputum culture positive for Pseudomonas aeruginosa, in patients with predominantly mild to moderate steady-state bronchiectasis. Acute exacerbations elicited reductions in FVC and FEV(1). Changes of other spirometric parameters were less significant during exacerbations. TRIAL REGISTRATION: ClinicalTrials.gov NCT01761214