H Gallagher1, J Soar2, C Tomson3. 1. South West Thames Renal Unit, Epsom and St Helier NHS Trust, Carshalton, UK. 2. Anaesthetics Department, Southmead Hospital, North Bristol NHS Trust, Bristol BS10 5NB, UK jasmeet.soar@nbt.nhs.uk. 3. Department of Renal Medicine, Freeman Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.