1 State Key Laboratory of Rare, Complex and Critical Diseases, Medical ICU, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, China.
2 Department of Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.
3 Bloomsbury Institute of Intensive Care Medicine, Division of Medicine, University College London (UCL), London, UK.