1. Division of Anaesthesia, University of Cambridge, Addenbrooke’s Hospital , Hills Road, Cambridge, CB2 0QQ , UK
2. Department of Perioperative , Acute, Critical, and Emergency Care (PACE), , Hills Road, Cambridge CB2 0QQ , UK
3. University of Cambridge, Addenbrooke’s Hospital , Acute, Critical, and Emergency Care (PACE), , Hills Road, Cambridge CB2 0QQ , UK
4. Department of Clinical Neurosurgery, University of Cambridge, Addenbrooke’s Hospital , Hills Road, Cambridge CB2 0QQ , UK
5. Department of Anaesthesia, Cambridge University Hospitals NHS Foundation Trust, Addenbrooke’s Hospital , Hills Road, Cambridge CB2 0QQ , UK
6. Department of Engineering, Health Systems Design Group , Trumpington Street, Cambridge CB2 1PZ , UK
7. Department of Anaesthesia, North West Anglia Foundation Trust, Peterborough City Hospital , Peterborough PE3 9GZ , UK
8. Department of Anaesthesia, Queen Elizabeth Hospital Kings Lynn NHS Foundation Trust , Gayton Road, Kings Lynn, PE30 4ET , UK
9. Department of Anaesthesia , Bedfordshire Hospital NHS Foundation Trust, , Lewsey Road, Luton, LU4 ODZ , UK
10. Luton and Dunstable University Hspital , Bedfordshire Hospital NHS Foundation Trust, , Lewsey Road, Luton, LU4 ODZ , UK
11. Department of Anaesthesia, James Paget University Hospitals NHS Foundation Trust , Lowestoft Road, Gorleston-on-Sea, Great Yarmouth NR31 6LA , UK
12. Older People’s Medicine Department, Norfolk and Norwich University Hospitals NHS Foundation Trust , Colney Lane, Norwich NR4 7UY , UK
13. Clinical Associate Professor in Translational and Clinical Medicine , Norwich Medical School, , Norwich , UK
14. University of East Anglia , Norwich Medical School, , Norwich , UK
15. Department of Anaesthesia , Northwest Anglia NHS Foundation Trust, , Parkway Hinchingbrooke, Huntingdon PE29 6NT , UK
16. Hinchingbrooke Hospital , Northwest Anglia NHS Foundation Trust, , Parkway Hinchingbrooke, Huntingdon PE29 6NT , UK
17. Department of Medicine, University of Cambridge, Addenbrooke’s Hospital , Hills Road, Cambridge CB2 0QQ , UK