Affiliation: | P. Murphy, FRCA, Senior Registrar, Department of Anaesthesia, Bristol Royal Infirmary, Bristol BS2 8HW, R. Erskine, FRCA, Senior Registrar, Department of Anaesthesia, Queens Medical Centre, Nottingham, J.A. Langton, FRCA, Senior Lecturer, University Department of Anaesthesia, Leicester Royal Infirmary, Leicester LE1 5WW. |