[1] Royal Victoria Infirm, Northern Oesophagogastr Unit, Newcastle Upon Tyne, Tyne & Wear, England
[2] Royal Victoria Infirm, Dept Anaesthesia & Crit Care Med, Newcastle Upon Tyne, Tyne & Wear, England
[3] Newcastle Univ, Sch Med Educ, Newcastle Upon Tyne, Tyne & Wear, England