title: Blood administration in helicopter emergency medical services patients associated with hypothermia.
abstract: BACKGROUND
  The infusion of packed red blood cells (PRBCs) in the severely injured patient is not a new practice. It is a potentially lifesaving procedure although it is not without inherent risk. This practice in the helicopter emergency medical services (HEMS) has not been examined in the literature. We attempt to determine factors associated with hypothermia (ie, < 35°C), including the transfusion of O negative blood.
  
  
  METHODS
  This was a retrospective review using our trauma registry on all patients who arrived at our rural level 1 trauma center by HEMS from January 1, 2005, through June 30, 2009. Patient temperature on arrival was compared for patients with and without hypothermia transported by our HEMS service.
  
  
  RESULTS
  During the study period, there were 707 HEMS transports by our service. Sixty (8.5%) were hypothermic, and 30 (4.2%) received PRBCs. There was a high likelihood of PRBC patients with hypothermia (odds ratio = 6.27; 95% confidence interval, 2.47-14.89; P < .05).
  
  
  CONCLUSIONS
  HEMS trauma patients who have received blood are more likely to arrive hypothermic (ie, < 35°C). The clinical impact of giving PRBCs in the HEMS prehospital setting was not determined.
authors.affiliation: Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA.
authors.forename: Renata
authors.initials: R
authors.lastname: Wheeler
authors.forename: Friedrich M
authors.initials: FM
authors.lastname: von Recklinghausen
authors.forename: Reed
authors.initials: R
authors.lastname: Brozen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017732:Air Ambulances; D004632:Emergency Medical Services / Q000379:methods*; D017707:Erythrocyte Transfusion / Q000009:adverse effects* / Q000379:methods; D005260:Female; D006801:Humans; D007035:Hypothermia / Q000209:etiology*; D015601:Injury Severity Score; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012189:Retrospective Studies; D014193:Trauma Centers; D055815:Young Adult