aUniversité Paris Cité, IAME, INSERM UMR1137

bAP-HP, Hôpital Bichat - Claude Bernard, Department of Intensive Care Medicine, F-75018 Paris, France

cNeurocritical Care Division, Departments of Neurosurgery and Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, USA

dUniversity Division of Anaesthesia, Department of Medicine, University of Cambridge, United Kingdom

Correspondence to Professor Romain Sonneville, MD, PhD, Service de médecine intensive - réanimation, Hôpital Bichat – Claude Bernard, 46 rue Henri Huchard, 75877 Paris Cedex, France. Tel: +33 1 40257703; fax: +33 1 40258782; e-mail: [email protected]