Massive Transfusion in Trauma

Hemorrhage is the second most common cause of death following injury and trauma, and is responsible for 20-40% of deaths. For those patients who survive, a distinct minority (1-3%) is massively transfused. Although many definitions of massive transfusion have been discussed in the literature, massive transfusion is most commonly defined as replacement of at least one blood volume or transfusion of ten or more packed red blood cells (RBCs) within 24 hours. Other definitions include the acute administration of 4 units of blood with the anticipation of continuing hemorrhage, or replacement of 50% of blood volume within 2 hours. Major risk factors for massive transfusion (85% predictable with ROC curves) include hypotension (systolic blood pressure less than 110 mm Hg), tachycardia (heart rate greater than 105 beats per minute), anemia (hematocrit less than 32%) and acidemia (pH less than 7.25). A physical exam and point of care testing or arterial blood gas sample can inexpensively aid providers in predicting who will require a massive transfusion.