Kor, Daryl J; Gajic, Ognjen; Current Opinion in Critical Care. 16(4):309-316, August 2010.
Purpose of review: The past two decades have witnessed an extensive re-evaluation of transfusion therapy in the intensive care unit (ICU). The purpose of this review is to present the current state of knowledge regarding blood transfusion in the critically ill and to identify gaps in our current understanding for future research.

Recent findings: Accumulating evidence suggests a lack of efficacy with red blood cell (RBC), plasma, and platelet transfusion in the majority of critically ill patients. Evidence has also increasingly exposed previously under-recognized transfusion risks. The result is a growing number of recommendations for more restrictive RBC, plasma, and platelet transfusion strategies. An important exception to a more conservative transfusion practice occurs in patients with major trauma and life-threatening bleeding. Delaying RBCs, plasma and platelet component therapies in this population can promote the lethal triad of coagulopathy, acidosis, and hypothermia with a resultant increase in bleeding, greater transfusion requirements, and higher mortality.

Summary: Although we have made substantial progress in understanding the role of blood transfusion in the ICU, multiple important knowledge gaps persist. Future studies are needed to better define and characterize the impact of RBC storage, male-only plasma and platelet donor procurement procedures, and transfusion strategies in those requiring massive transfusion and with acute local or global tissue ischemia.

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