1 Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Faculty of Medicine, Prince of Wales Hospital, Shatin, New Territories, Hong Kong, SAR, China.
2 Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Faculty of Medicine, Prince of Wales Hospital, Shatin, New Territories, Hong Kong, SAR, China karmakar@cuhk.edu.hk.