title: Early packed red blood cell transfusion and acute respiratory distress syndrome after trauma.
abstract: BACKGROUND
  Transfusion of packed red blood cells (PRBCs) is a risk factor for acute respiratory distress syndrome (ARDS) in trauma patients. Yet, there is a paucity of information regarding the risk of ARDS with incremental PRBCs exposure.
  
  
  METHODS
  For this retrospective analysis, eligible patients from National Study on Costs and Outcomes of Trauma were included. Our main exposure was defined as units of PRBCs transfused during the first 24 h after admission. The main outcome was ARDS.
  
  
  RESULTS
  A total of 521 (4.6%) of 14070 patients developed ARDS, and 331 patients (63.5%) who developed ARDS received PRBCs transfusion. Injury severity, thoracic injury, polytrauma, and pneumonia receiving more than 5 units of fresh frozen plasma and 6-10 units of PRBCs were independent predictors of ARDS. Patients receiving more than 5 units of PRBCs had higher risk of developing ARDS (patients who received 6-10 units: adjusted odds ratio 2.5, 95% CI 1.12-5.3; patients who received more than 10 units: odds ratio 2.6, 95% CI 1.1-6.4). Each additional unit of PRBCs transfused conferred a 6% higher risk of ARDS (adjusted odds ratio 1.06; 95% CI 1.03-1.10).
  
  
  CONCLUSIONS
  Early transfusion of PRBCs is an independent predictor of ARDS in adult trauma patients. Conservative transfusion strategies that decrease PRBC exposure by even 1 unit may be warranted to reduce the risk of ARDS in injured patients.
authors.affiliation: Department of Anesthesiology, University of Washington School of Medicine, Seattle, Washington 98195-6540, USA.
authors.forename: Onuma
authors.initials: O
authors.lastname: Chaiwat
authors.forename: John D
authors.initials: JD
authors.lastname: Lang
authors.forename: Monica S
authors.initials: MS
authors.lastname: Vavilala
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.forename: Ellen J
authors.initials: EJ
authors.lastname: MacKenzie
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Jurkovich
authors.forename: Frederick P
authors.initials: FP
authors.lastname: Rivara
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016208:Databases, Factual; D017707:Erythrocyte Transfusion / Q000009:adverse effects*; D005260:Female; D015600:Glasgow Coma Scale; D017052:Hospital Mortality; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009104:Multiple Trauma / Q000150:complications / Q000628:therapy; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012128:Respiratory Distress Syndrome / Q000453:epidemiology* / Q000209:etiology* / Q000401:mortality; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D012307:Risk Factors; D014193:Trauma Centers / Q000706:statistics & numerical data; D016896:Treatment Outcome; D014947:Wounds and Injuries / Q000150:complications* / Q000401:mortality / Q000628:therapy*; D055815:Young Adult