1 Department of Anaesthesia, North West School of Anaesthesia, Manchester, United Kingdom.
2 Department of Anaesthesia, Mersey School of Anaesthesia, Liverpool, United Kingdom, ssuichingk@gmail.com.
3 Wythenshawe Hospital, Manchester, University National Health Service (NHS) Foundation Trust, Manchester, United Kingdom, Lancaster Medical School, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom.