1 From the Newcastle upon Tyne NHS Foundation Trust, Newcastle upon Tyne, UK (NR), Department of Anaesthesiology and Critical Care, Policlinico Umberto I Hospital, La Sapienza University of Rome, Rome, Italy (FB), Department of Anaesthesiology and Intensive Care Medicine, Charité Campus Benjamin Franklin, Berlin, Germany (IA) and Department of Anaesthesiology and Intensive Care, 'Grigore T. Popa' University of Medicine and Pharmacy, Iasi, Romania (IG).