Clinical characteristics of COPD patients with tidal expiratory flow limitation

Abstract

James Dean,1 Umme Kolsum,1,2 Paul Hitchen,1 Vandana Gupta,1 Dave Singh1,2 1Medicines Evaluation Unit, Manchester, 2Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester and University Hospital of South Manchester NHS Foundation Trust, Manchester, UK Abstract: We have used impulse oscillometry to identify COPD patients with tidal expiratory flow limitation (EFL), which is a measurement related to small airway disease. We report that 37.4% of COPD patients had EFL; these patients had multiple clinical characteristics of more severe disease including lower forced expiratory volume in 1 second values, greater hyperinflation, reduced exercise performance, and increased small airway impairment. We highlight that EFL can be used to identify a subgroup of COPD patients with distinct characteristics associated with small airway disease. Keywords: COPD, expiratory flow limitation, IOS, small airway, reactance

Keywords

• COPD
• expiratory flow limitation
• IOS
• small airway
• reactance