title: Impact of the age of stored blood on trauma patient mortality: a systematic review.
abstract: BACKGROUND
  The impact of the age of stored red blood cells on mortality in patients sustaining traumatic injuries requiring transfusion of blood products is unknown. The objective of this systematic review was to identify and describe the available literature on the use of older versus newer blood in trauma patient populations.
  
  
  METHODS
  We searched PubMed, Embase, Lilac and the Cochrane Database for published studies comparing the transfusion of newer versus older red blood cells in adult patients sustaining traumatic injuries. Studies included for review reported on trauma patients receiving transfusions of packed red blood cells, identified the age of stored blood that was transfused and reported patient mortality as an end point. We extracted data using a standardized form and assessed study quality using the Newcastle-Ottawa Scale.
  
  
  RESULTS
  Seven studies were identified (6780 patients) from 3936 initial search results. Four studies reported that transfusion of older blood was independently associated with increased mortality in trauma patients, while 3 studies did not observe any increase in patient mortality with the use of older versus newer blood. Three studies associated the transfusion of older blood with adverse patient outcomes, including longer stay in the intensive care unit, complicated sepsis, pneumonia and renal dysfunction. Studies varied considerably in design, volumes of blood transfused and definitions applied for old and new blood..
  
  
  CONCLUSIONS
  The impact of the age of stored packed red blood cells on mortality in trauma patients is inconclusive. Future investigations are warranted.
authors.affiliation: From the Department of Emergency Medicine, Dalhousie University, Halifax, NS, Canada (Sowers, Froese, Green); the Department of Critical Care Medicine, Dalhousie University, Halifax, NS, Canada (Green); and Trauma Nova Scotia, Halifax, NS, Canada (Erdogan, Green).
authors.forename: Nicholas
authors.initials: N
authors.lastname: Sowers
authors.affiliation: From the Department of Emergency Medicine, Dalhousie University, Halifax, NS, Canada (Sowers, Froese, Green); the Department of Critical Care Medicine, Dalhousie University, Halifax, NS, Canada (Green); and Trauma Nova Scotia, Halifax, NS, Canada (Erdogan, Green).
authors.forename: Patrick C
authors.initials: PC
authors.lastname: Froese
authors.affiliation: From the Department of Emergency Medicine, Dalhousie University, Halifax, NS, Canada (Sowers, Froese, Green); the Department of Critical Care Medicine, Dalhousie University, Halifax, NS, Canada (Green); and Trauma Nova Scotia, Halifax, NS, Canada (Erdogan, Green).
authors.forename: Mete
authors.initials: M
authors.lastname: Erdogan
authors.affiliation: From the Department of Emergency Medicine, Dalhousie University, Halifax, NS, Canada (Sowers, Froese, Green); the Department of Critical Care Medicine, Dalhousie University, Halifax, NS, Canada (Green); and Trauma Nova Scotia, Halifax, NS, Canada (Erdogan, Green).
authors.forename: Robert S
authors.initials: RS
authors.lastname: Green
mesh_terms: D001793:Blood Preservation / Q000592:standards*; D017707:Erythrocyte Transfusion / Q000592:standards*; D006801:Humans; D013997:Time Factors; D014947:Wounds and Injuries / Q000401:mortality* / Q000628:therapy*