NIHR Surgical Reconstruction and Microbiology Research Centre, Queen Elizabeth Hospital, Birmingham, UK. College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK. West Midlands Ambulance Service NHS Foundation Trust, Brierley Hill, UK. Midlands Air Ambulance Charity, Stourbridge, West Midlands, UK. Thames Valley Air Ambulance, RAF Benson, Oxfordshire, UK. NHS Blood and Transplant, Birmingham, UK. Critical Care Medicine, University of Warwick, Coventry, UK. School of Biomedical Sciences, Faculty of Medicine, University of Queensland, Brisbane, Australia.