title: The impact of providing blood to the scene of an accident on transfusion laboratory practice.
abstract: BACKGROUND
  Haemorrhage is the leading cause of mortality during trauma. In 2012, London's Air Ambulance introduced Blood on Board (BOB), transfusing group O red cells (RBC) to trauma patients at the scene.
  
  
  OBJECTIVE
  This study assessed the impact of BOB on the number of mixed field samples received by the laboratory, the number of group O RBC transfused to non-group O patients and the ratio of RBC to fresh frozen plasma (FFP) transfused in the initial 24 h.
  
  
  METHODS
  Three major trauma centres collected data on patients for whom the major haemorrhage protocol was activated between August 2008 and February 2012 pre-BOB and March 2012 and December 2013 post-BOB.
  
  
  RESULTS
  A total of 233 trauma patients were identified pre-BOB and 119 post-BOB. There was no significant difference in the percentage of group O units transfused to non-group O patients (75 vs 82%, P = 0·21) or the RBC : FFP ratio (pre-BOB mean 1·6 [interquartile range (IQR) 1·0-2·0]; post-BOB mean 1·7 [IQR 1·1-2·2], P = 0·24). There was no significant difference in the percentage of mixed field samples received (23% vs 27%, P = 0·3).
  
  
  CONCLUSIONS
  The introduction of BOB did not change the proportion of group O RBC transfused or the RBC : FFP ratio; however, the proportion of acceptable samples decreased. This is largely due to an increase in blood samples not received from the post-BOB cohort, which we believe is probably due to patients who died at the scene. We have introduced robust systems to indicate reasons for not obtaining samples.
authors.affiliation: Department of Hematology, Barts Health NHS Trust, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Wolf
authors.affiliation: Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
authors.forename: J
authors.initials: J
authors.lastname: Morris
authors.affiliation: Department of Hematology, Barts Health NHS Trust, London, UK.
authors.forename: K
authors.initials: K
authors.lastname: Kennedy
authors.affiliation: Kings College Hospital, London, UK.
authors.forename: M
authors.initials: M
authors.lastname: Lawn
authors.affiliation: Department of Hematology, Barts Health NHS Trust, London, UK.
authors.forename: T
authors.initials: T
authors.lastname: Mcloughlin
authors.affiliation: St George's Healthcare NHS Trust, London, UK.
authors.forename: K
authors.initials: K
authors.lastname: Feane
authors.affiliation: St George's Healthcare NHS Trust, London, UK.
authors.forename: J
authors.initials: J
authors.lastname: Uprichard
authors.affiliation: Department of Hematology, Barts Health NHS Trust, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Weaver
authors.affiliation: Department of Hematology, Barts Health NHS Trust, London, UK.|NHS Blood and Transplant, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Allard
authors.affiliation: Department of Hematology, Barts Health NHS Trust, London, UK.|Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK.|NHS Blood and Transplant, London, UK.
authors.forename: L
authors.initials: L
authors.lastname: Green
mesh_terms: D000017:ABO Blood-Group System; D000552:Ambulances; D058731:Blood Safety; D017707:Erythrocyte Transfusion; D005260:Female; D006470:Hemorrhage / Q000628:therapy*; D006801:Humans; D008131:London; D008297:Male; D014947:Wounds and Injuries / Q000628:therapy*
chemical_list: D000017:ABO Blood-Group System
keywords: haemorrhage; laboratory practice; pre-hospital; resuscitation; trauma