1. Department of Anaesthesia and Perioperative Medicine, North Shore Hospital, Department of Anaesthesiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
2. Faculty of Medical and Health Sciences, University of Auckland, Department of Adult and Emergency Anaesthesia, Auckland City Hospital, Auckland, New Zealand
3. Department of Anaesthesiology, Faculty of Medical and Health Sciences, University of Auckland, Department of Adult and Emergency Anaesthesia, Auckland City Hospital, Auckland, New Zealand