Should we increase the ratio of plasma/platelets to red blood cells in massive transfusion: what is the evidence?

Introduction: Based on relatively recent clinical work, considerable enthusiasm has been generated for the increased use of plasma and platelet in the earlier resuscitation of massively transfused patients. The aim of this review was to examine the currently available evidence for the increase in plasma/platelet to red cell transfusion ratio during massive transfusion.
Methods: In May of 2009, a systematic review of studies reporting the effects of plasma and platelet to red cell component transfusion ratio on mortality outcome was performed.
Results: There were no prospective randomized controlled trials on this topic. Eleven retrospective studies were identified evaluating the effects of plasma : red cell ratio on mortality in massive transfusion after trauma. Most studies demonstrated a survival advantage of increased plasma ratio in massive transfusion. While the majority of the studies suggested the optimal plasma : red cell ratio to be 1 : 2 or higher, others demonstrated the optimal ratio to be lower. Three of these studies also demonstrated a survival advantage with increased platelet : red cell transfusion ratio.
Conclusion: Although there is some evidence to support the increase use of plasma and platelets in massive transfusion, the true efficacy of such practice has not yet been proven by prospective randomized controlled trials. The available retrospective studies raise many important questions that need to be addressed in future clinical trials.