University of Valladolid - Clinical Hospital, University of Valencia - Faculty of Medicine, University of Barcelona - Faculty of Medicine, BioCritic. Group for Biomedical Research in Critical Care Medicine, Hospital Clinico San Carlos, Hospital Clínico de Valladolid, Hospital Universitario de Fuenlabrada, University Hospital Marques de Valdecilla - Department of Anesthesiology, University Hospital Ribera Povisa - Department of Anesthesiology, University Hospital of Gran Canaria Dr. Negrin, University Hospital of Gran Canaria Dr. Negrin, University Hospital of Manises - Department of Anesthesiology, University of Barcelona - Faculty of Medicine, Hospital Universitario de Salamanca, University of Valladolid - Clinical Hospital, Parc Taulí Hospital Universitari, University Hospital Álvaro Cunqueiro - Department of Anesthesiology, University Hospital of Donostia - Department of Anesthesiology, University Hospital Álvaro Cunqueiro - Department of Anesthesiology, Castellon University - Castellon University General Hospital, Hospital Universitario Lucus Augusti (HULA), Universidade de Santiago de Compostela - Faculty of Medicine, University of Valencia - Department of Anaesthesia, Hospital San Pau - Department of Anesthesiology, University of A Coruña - Department of Anesthesiology, Hospital Universitario Cruces, University Hospital of Cabueñes - Department of Anesthesiology, Miguel Servet University Hospital, Hospital Universitario de León, Instituto de Investigación Sanitaria Hospital "12 de Octubre" - Hospital Universitario 12 de Octubre, University of the Basque Country - Hospital de Cruces, BioCritic. Group for Biomedical Research in Critical Care Medicine, University of the Basque Country - Hospital de Cruces, University Hospital of Bellvitge, University of Valladolid - Clinical Hospital, BioCritic. Group for Biomedical Research in Critical Care Medicine, BioCritic. Group for Biomedical Research in Critical Care Medicine, Hospital Universitario Basurto, University Hospital Álvaro Cunqueiro - Department of Anesthesiology, Hospital Universitario de Salamanca, Ferrol University Hospital Complex - Department of Anesthesiology, University Hospital Puerta del Hierro - Department of Anesthesiology, University of Burgos - Hospital Universitario de Burgos, Hospital Universitario Central de Asturias, Hospital Universitario San Cecilio de Granada, Hospital Clínico Universitario Valladolid, University Hospital of Tajo - Department of Anesthesiology, Monforte de Lemos Hospital - Department of Anesthesiology, University Hospital Complex of Ourense - Department of Anesthesiology, Quirón Salud Valle del Henares Hospital - Department of Anesthesiology, University Hospital of Pontevedra - Department of Anaesthesiology, University of Valencia - Department of Anesthesiology and Intensive Care, University of Valladolid - Clinical Hospital, BioCritic. Group for Biomedical Research in Critical Care Medicine, BioCritic. Group for Biomedical Research in Critical Care Medicine, University of Valencia - Department of Anesthesiology and Intensive Care and Independent