L Savic1, S Savic2, P M Hopkins3. 1. Department of Anaesthesia, Leeds Teaching Hospitals NHS Trust, Leeds, UK. 2. Department of Clinical Immunology, Leeds Teaching Hospitals NHS Trust, Leeds, UK; Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Leeds, UK. 3. Department of Anaesthesia, Leeds Teaching Hospitals NHS Trust, Leeds, UK; Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK. Electronic address: p.m.hopkins@leeds.ac.uk.