Blood transfusion in trauma patients: unresolved questions.

Massive transfusion is an essential part of resuscitation efforts in acute trauma patients. The goal is to quickly correct trauma-induced coagulopathy and replace red blood cell (RBC) mass with the minimal number as well as the appropriate choice of blood components to minimize the possible adverse effects of transfusions. Early trauma induced coagulopathy (ETIC) is present in about 20% of patients upon hospital admission and predicts for decreased survival. The mechanism of ETIC is still being elucidated; however, most theories of ETIC's pathophysiology justify the early use of plasma. Most massive transfusion protocol (MTP) ratios deliver blood products in a ratio of 1:1:1 for RBCs:plasma:platelets, which is supported by the majority of the literature demonstrating improved patient survival with higher ratios (>1 plasma and platelet for every 2 RBCs transfused). Indeed, formula-driven MTPs allow trauma services to react quickly to ETIC and provide coagulation factors and platelets in these ratios without having to wait for the results of coagulation assays while the patient's coagulopathy worsens. New MTPs are being created which are adjusted according to an individual's coagulation laboratory values based on point-of-care laboratory tests, such as thromboelastography. When creating an MTP, product wastage due to inappropriate activation and improper product storage should be considered and closely monitored. Another area of discussion regarding transfusion in trauma includes the potential association of prolonged storage of RBCs and adverse outcomes, which has yet to be confirmed. Significant progress has been made in the transfusion management of trauma patients, but further studies are required to optimize patient care and outcomes.