1. Department of Intensive Care Medicine, Multidisciplinary Intensive Care Research Organisation (MICRO), St James's Hospital, Dublin, Ireland
2. CIBER of Respiratory Diseases (CIBERES), Institute of Health Carlos III, Madrid
3. Pulmonary Department, Hospital Clinic, Universitat de Barcelona, IDIBAPS, ICREA, Barcelona, Spain
4. Section of Pulmonary & Critical Care Medicine, South Texas Veterans Healthcare System, GRECC and University of Texas Health San Antonio, San Antonio, Texas, USA