LCI measurement is coming of age

Background: Lung clearance index (LCI) derived from multiple-breath washout (MBW) is an established proxy of small airways function in children with cystic fibrosis (CF). Yet, LCI has not been systematically studied in adults with prevalent chronic lung diseases using available and validated MBW setups and protocols. Methods: 33 asymptomatic smokers and 54 patients with chronic obstructive airway disease (asthma n = 20, COPD n = 20, CF n = 14) performed spirometry and nitrogen (N2)-MBW using the ExhalyzerD® in a tertiary care center. LCI was analysed at 2 endpoints: at 1/40th (standard) and earlier at 1/20th (sh…