Thayur R Madhusudhan1
, Srivatsa Sambamurthy2
, Eileen Williams3
and Ian C Smith4 
1Registrar, Department of Orthopaedics, Glan Clwyd hospital, Rhyl, UK
2Registrar, Department of Anaesthesia, Glan Clwyd hospital, Rhyl, UK
3Consultant, Department of Anaesthesia, Glan Clwyd hospital, Rhyl, UK
4Consultant, Department of Orthopaedics, Glan Clwyd hospital, Rhyl, UK