The Use of Higher Platelet:RBC Transfusion Ratio in the Acute Phase of Trauma Resuscitation: A Systematic Review

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. Data Sources: We systematically searched Medline, Embase, Web of Science, Biosis, Cochrane Central, and Scopus. Study Selection: 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. Data Extraction: 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. Data Synthesis: 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.