Editorial Board: Antonio Anzueto (San Antonio, TX, USA), Leif Bjermer (Lund, Sweden), John R. Hurst (London, UK) and Carlos Robalo Cordeiro (Coimbra, Portugal). Managing Editor: Rachel Gozzard European Respiratory Society, 442 Glossop Road, Sheffield, S10 2PX, UK Tel: 44 114 2672860 | E-mail: monograph@ersj.org.uk Published by European Respiratory Society ©2018 June 2018 Print ISBN: 978-1-84984-095-8 Online ISBN: 978-1-84984-096-5 Print ISSN: 2312-508X Online ISSN: 2312-5098 Typesetting by Nova Techset Private Limited Printed by Charlesworth Press All material is copyright to European Respiratory Society. It may not be reproduced in any way including electronic means without the express permission of the company. Statements in the volume reflect the views of the authors, and not necessarily those of the European Respiratory Society, editors or publishers.