1 Department of Anaesthesia, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom, roseita@gmail.com Haemophilia Centre, Barts Health NHS Trust, London, United Kingdom Department of Haematology, Barts Health NHS Trust, London, United Kingdom Queen Mary University of London, London, United Kingdom NHS Blood and Transplant, London, United Kingdom Department of Haematology, Barts and The London School of Medicine and Dentistry, London, United Kingdom Queen Mary University of London, London, United Kingdom Barts Health NHS Trust, London, United Kingdom.