1. * Research Fellow in Anaesthesia,
2. † Specialist Registrar in Anaesthesia,
3. ‡ Consultant Anaesthetist, Department of Anaesthesia, University College Hospital, Galway.
4. § Professor of Anaesthesia and Consultant Anaesthetist, Department of Anaesthesia, University College Hospital, Galway, Ireland; Department of Anaesthesia, Clinical Sciences Institute, National University of Ireland.