1 From the Anesthesiology Division, Integrated Hospital Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, United Arab Emirates (ML, BT, SM), Department of Anesthesia and Intensive Care, University General Hospital of Valencia Department of Methodology, Universidad Europea de Valencia, Valencia, Spain (CSR), Azienda Ospedaliero Universitaria Pisana, Cardiothoracic and vascular Anaesthesia and Intensive Care, Pisa (FG), Department of Translational Medicine, Universita' degli Studi del Piemonte Orientale, Novara (GC), Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, Chieti, Italy (LV), Peterfy Sandor Hospital, Anesthesia and Intensive Care Unit, Budapest, Hungary (FL), Servei d'Anestesiologia i Medicina Periopeatoria, Hospital General de Granollers, Granollers, Spain (JJMF), Department of Anaesthesia and Intensive Care, University Hospital Tulln, Tulln an der Donau, Austria (AD), Department of Anaesthesiology and Intensive Care Medicine, Hospital of Merano (SABESASDAA), Merano - Meran, Italy (MB, SR), the Outcomes Research Consortium, Department of Anesthesiology, Cleveland Clinic, Cleveland, Ohio, USA (KR), Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, Rostock University Medical Center, Rostock, Germany (DAR), Anesthesia and Intensive Care. Policlinico "G.Rodolico-San Marco", Catania (LLV), Anesthesia and Intensive Care, Giovanni Paolo II Hospital, Ragusa, Italy (MS), Rigshospitalet & Institute of Clinical Medicine, University of Copenhagen Department of Paediatric and Obstetric Anaesthesia, Juliane Marie Centre, Rigshospitalet, Denmark University of Copenhagen, Copenhagen, Denmark (AA).