title: The use of higher platelet: RBC transfusion ratio in the acute phase of trauma resuscitation: a systematic review.
abstract: OBJECTIVE
  With the recognition of early coagulopathy, trauma resuscitation has shifted toward liberal platelet transfusions. The overall benefit of this strategy remains controversial. Our objective was to compare the effects of a liberal use of platelet (higher platelet:RBC ratios) with a conservative approach (lower ratios) in trauma resuscitation.
  
  
  METHODS
  We systematically searched Medline, Embase, Web of Science, Biosis, Cochrane Central, and Scopus.
  
  
  METHODS
  Two independent reviewers selected randomized controlled trials and observational studies comparing two or more platelet:RBC ratios in trauma resuscitation. We excluded studies investigating the use of whole blood or hemostatic products.
  
  
  METHODS
  Two independent reviewers extracted data and assessed the risk of bias. Primary outcomes were early (in ICU or within 30 d) and late (in hospital or after 30 d) mortality. Secondary outcomes were multiple organ failure, lung injury, and sepsis.
  
  
  RESULTS
  From 6,123 citations, no randomized controlled trials were identified. We included seven observational studies (4,230 patients) addressing confounders through multivariable regression or propensity scores. Heterogeneity of studies precluded meta-analysis. Among the five studies including exclusively patients requiring massive transfusions, four observed a lower mortality with higher ratios. Two studies considering nonmassively bleeding patients observed no benefit of using higher ratios. Two studies evaluated the implementation of a massive transfusion protocol; only one study observed a decrease in mortality with higher ratios. Of the two studies at low risk of survival bias, one study observed a survival benefit. Three studies assessed secondary outcomes. One study observed an increase in multiple organ failure with higher ratios, whereas no study demonstrated an increased risk in lung injury or sepsis.
  
  
  CONCLUSIONS
  There is insufficient evidence to strongly support the use of a precise platelet:RBC ratio for trauma resuscitation, especially in nonmassively bleeding patients. Randomized controlled trials evaluating both the safety and efficacy of liberal platelet transfusions are warranted.
authors: 1Centre de recherche du CHU de Québec, Santé des populations et pratiques optimales en santé, Université Laval, Québec, Québec, Canada. 2Department of Surgery, Université Laval, Québec City, Québec, Canada. 3Department of Medicine, Université Laval, Québec City, Québec, Canada. 4Division of Critical Care Medicine, Department of Anesthesiology, Université Laval, Québec City, Québec, Canada. 5Department of Family Medicine and Emergency Medicine, Université Laval, Québec City, Québec, Canada. 6CancerCare Manitoba, Winnipeg, Manitoba, Canada. 7Department of Internal Medicine, Sections of Critical Care and Hematology/Medical Oncology, University of Manitoba, Winnipeg, Manitoba, Canada.
authors: Julie
authors: J
authors: Hallet
authors: François
authors: F
authors: Lauzier
authors: Olivier
authors: O
authors: Mailloux
authors: Vincent
authors: V
authors: Trottier
authors: Patrick
authors: P
authors: Archambault
authors: Ryan
authors: R
authors: Zarychanski
authors: Alexis F
authors: AF
authors: Turgeon
mesh_terms: D017707:Erythrocyte Transfusion; D006470:Hemorrhage / Q000209:etiology / Q000628:therapy*; D006801:Humans; D017713:Platelet Transfusion; D012151:Resuscitation; D014947:Wounds and Injuries / Q000150:complications / Q000401:mortality / Q000628:therapy*