1. Department of Surgery and Cancer, St Mary's Hospital; Imperial College London; London UK
2. Department of Anaesthetics, Pain Medicine and Intensive Care, Chelsea and Westminster Hospital; Imperial College London; London UK
3. Department of Anaesthetics, Royal Brompton and Harefield NHS Foundation Trust; Harefield Hospital; Harefield UK
4. Department of Anaesthesia and Intensive Therapy; Semmelweis University; Budapest Hungary