Kariem El-Boghdadly1,2, Morné Wolmarans3, Angela D Stengel4, Eric Albrecht5, Ki Jinn Chin6, Hesham Elsharkawy7,8, Sandra Kopp9, Edward R Mariano10,11, Jeff L Xu12,13, Sanjib Adhikary14, Başak Altıparmak15, Michael J Barrington16, Sébastien Bloc17,18, Rafael Blanco19, Karen Boretsky20, Jens Børglum21, Margaretha Breebaart22, David Burckett-St Laurent23, Xavier Capdevila24, Brendan Carvalho25, Alwin Chuan26, Steve Coppens27, Ioana Costache28, Mette Dam29, Christian Egeler30, Mario Fajardo31, Jeff Gadsden32, Philippe Emmanuel Gautier33, Stuart Alan Grant34, Admir Hadzic35,36, Peter Hebbard37, Nadia Hernandez38, Rosemary Hogg39, Margaret Holtz40, Rebecca L Johnson41, Manoj Kumar Karmakar42, Paul Kessler43, Kwesi Kwofie44, Clara Lobo45, Danielle Ludwin46, Alan MacFarlane47, John McDonnell48, Graeme McLeod49,50, Peter Merjavy51, Eml Moran52, Brian D O'Donnell53, Teresa Parras54, Amit Pawa55,56, Anahi Perlas57, Maria Fernanda Rojas Gomez58, Xavier Sala-Blanch59,60, Andrea Saporito61, Sanjay Kumar Sinha62, Ellen M Soffin63, Athmaja Thottungal64, Ban C H Tsui65, Serkan Tulgar66, Lloyd Turbitt67, Vishal Uppal68, Geert J van Geffen69, Thomas Volk70,71, Nabil M Elkassabany72,73. 1. Department of Anaesthesia and Perioperative Medicine, Guy's and St Thomas' NHS Foundation Trust, London, UK. 2. Centre for Human & Applied Physiological Sciences, King's College London, London, UK. 3. Anaesthesiology, Norfolk and Norwich University Hospital NHS Trust, Norwich, Norfolk, UK. 4. American Society of Regional Anesthesia and Pain Medicine, Pittsburgh, Pennsylvania, USA. 5. Department of Anaesthesia, University of Lausanne, Lausanne, Switzerland. 6. Department of Anesthesia, University of Toronto, Toronto, Ontario, Canada. 7. Anesthesiology, Cleveland Clinic, Cleveland, Ohio, USA. 8. Case Western Reserve University, Cleveland, Ohio, USA. 9. Anesthesiology, Mayo Clinic Graduate School for Biomedical Sciences, Rochester, Minnesota, USA. 10. Anesthesiology and Perioperative Care Service, VA Palo Alto Health Care System, Palo Alto, California, USA. 11. Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, California, USA. 12. Anesthesiology, Westchester Medical Center, Valhalla, New York, USA. 13. New York Medical College, Valhalla, New York, USA. 14. Anesthesiology and Perioperative Medicine, Penn State, University Park, Pennsylvania, USA. 15. Anesthesiology, Mugla Sitki Kocman Universitesi, Mugla, Turkey. 16. St Vincent's Hospital Melbourne Pty Ltd, Fitzroy, Victoria, Australia. 17. Anesthesiology Department, Ambroise Pare Hospital Group, Neuilly-sur-Seine, Île-de-France, France. 18. Clinical Research Department, Ambroise Pare Hospital Group, Neuilly-sur-Seine, Île-de-France, France. 19. Anaesthesia and Intensive Care, King's College Hospital Dubai, Abu Dhabi, UAE. 20. Anesthesiology, Critical Care and Pain Medicine, Harvard University, Cambridge, Massachusetts, USA. 21. Department of Anesthesiology, Zealand University Hospital Roskilde, Roskilde, Sjaelland, Denmark. 22. Department of Health Sciences, University of Antwerp, Antwerpen, Belgium. 23. Anaesthesia, Royal Gwent Hospital, Newport, UK. 24. Anesthesiology and Critical Care department, Hôpital Lapeyronie, Montpellier, Languedoc-Roussillon, France. 25. Stanford University, Stanford, California, USA. 26. University of New South Wales Faculty of Medicine, Putney, New South Wales, Australia. 27. Anesthesiology, KU Leuven, Leuven, Brabant, Belgium. 28. Anesthesia, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada. 29. Anaesthesiology, Zealand University Hospital Koge, Koge, Sjælland, Denmark. 30. Swansea Bay University Health Board, Wales, UK. 31. Anesthesiology, Hospital Universitario de Mostoles, Mostoles, Madrid, Spain. 32. Duke University Medical Center, Durham, North Carolina, USA. 33. Department of Anesthesia, CHIREC, Bruxelles, Belgium. 34. Anesthesiology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA. 35. Department of Anesthesiology, Ziekenhuis Oost-Limburg, Genk, Limburg, Belgium. 36. NYSORA, New York, New York, USA. 37. Department of Anesthesia Northeast Health Wangaratta, Ultrasound Education Group, The University of Melbourne Rural Health Academic Centre - Wangaratta, Wangaratta, Victoria, Australia. 38. Anesthesiology, University of Texas McGovern Medical School, Houston, Texas, USA. 39. Department of Anaesthesia, Belfast Health and Social Care Trust, Belfast, UK. 40. Georgia Anesthesiologists PC, Marietta, Georgia, USA. 41. Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, USA. 42. Department of Anesthesia and Intensice Care, The Chinese University of Hong Kong, Hong Kong, Hong Kong. 43. Anesthesiology, Intensive Care and Pain Medicine, Universitätsklinikum Frankfurt, Frankfurt am Main, Hessen, Germany. 44. Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada. 45. Anestesiologia, Hospital das Forças Armadas Polo do Porto, Porto, Portugal. 46. Columbia University Medical Center, New York, New York, USA. 47. Department of Cardiology, Glasgow Royal Infirmary, Glasgow, UK. 48. University Hospital Galway, Galway, Ireland. 49. Department of Anaesthesia, Ninewells Hospital, Dundee, UK. 50. Instittute of Academic Anaesthesia, University of Dundee, Dundee, UK. 51. Southern Health and Social Care Trust, Norwich, UK. 52. Letterkenny University Hospital, Letterkenny, Donegal, Ireland. 53. Department of Anesthesia and Intensive Care Medicine, Cork University Hospital, Cork, Ireland. 54. St George's Healthcare NHS Trust, London, UK. 55. Department of Anaesthesia, St Thomas' Hospital, London, UK. 56. Regional Anaesthesia - UK, London, UK. 57. Anesthesia and Pain Management, Toronto Western Hospital, Toronto, Ontario, Canada. 58. Clinica Cirulaser Andes, Bogata, Colombia. 59. Anesthesiology, Hospital Clinic de Barcelona, Barcelona, Spain. 60. Human Anatomy and Embryology, University of Barcelona Faculty of Medicine, Barcelona, Spain. 61. Anesthesia, Ospedale Regionale di Bellinzona e Valli Bellinzona, Bellinzona, Switzerland. 62. Anesthesiology, Saint Francis Hospital and Medical Center, Hartford, Connecticut, USA. 63. Department of Anesthesiology, Critical Care and Pain Management, Hospital for Special Surgery, New York, New York, USA. 64. Kent and Canterbury Hospital, Canterbury, Kent, UK. 65. Anesthesiology, Perioperative and Pain Medicine, Stanford University, Palo Alto, California, USA. 66. Anesthesiology and reanimatiom, Maltepe Universitesi Tip Fakultesi, Maltepe, Turkey. 67. Royal Victoria Hospital Laboratory and Mortuary Services, Belfast, UK. 68. Anesthesia, Dalhousie University - Faculty of Health Professions, Halifax, Nova Scotia, Canada. 69. Anesthesiology, Radboud University Nijmegen, Nijmegen, Gelderland, The Netherlands. 70. Department of Anaesthesiology, Intensive Care and Pain Therapy, Saarland University Hospital and Saarland University Faculty of Medicine, Homburg, Saarland, Germany. 71. Saarland University, Saarbrucken, Saarland, Germany. 72. Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, USA nabil.elkassabany@uphs.upenn.edu. 73. University of Pennsylvania, Philadelphia, Pennsylvania, USA.