Association of Shock, Coagulopathy, and Initial Vital Signs With Massive Transfusion in Combat Casualties

Background: Timely initiation of a massive transfusion (MT) protocol is associated with improved survival and reduced transfusion for patients requiring MT; however, a priori identification of this population is difficult. The objective of this study was to compare the results of an MT prediction model and actual MT incidence in combat casualties. Methods: We performed a retrospective review of the Joint Theater Trauma Registry transfusion database for all US service personnel injured in combat during overseas contingency operations who received at least 1 unit of blood. Systolic blood pressure at the time of admission, heart rate, hemoglobin, international normalized ratio, and base deficit were used in a previously developed prediction model for MT. Results: Casualties (n = 1124) were identified who had received at least 1 unit of blood and had all data points. Of these patients, 420 patients (37%) received an MT. Subjects presenting with any two of four possible variables (heart rate >110, systolic blood pressure <110 mm Hg, base deficit <=-6, and hemoglobin <11) had a 54% incidence of MT with a model sensitivity of 69%. Patients predicted but not observed to receive an MT had earlier time of death and an increased incidence of head injuries compared with those predicted and observed to receive an MT. Patients not predicted but observed to receive an MT had increased chest, abdominal, and extremity injuries than those neither predicted nor observed to receive an MT. Conclusion: The decision to implement an MT seems to rely heavily on clinical evaluation of severity of abdominal and extremity injury rather than physiologic derangement. Using a model based on the physiologic parameters-a more objective measure-may decrease mortality in combat casualties.