Predicting When to Administer Blood Products During Tactical Aeromedical Evacuation: Evaluation of a US Model

The administration of blood products to battlefield casualties in the prehospital arena has contributed significantly to the survival of critically injured patients in Afghanistan over the past 5 years. Given as part of an established military "chain of survival," blood product administration has represented a step-change improvement in capability for both UK and US tactical aeromedical evacuation (TACEVAC) platforms. The authors explore current concepts, analyzing and exploring themes associated with early use of blood products (fresh frozen plasma [FFP] and red blood cells [RBCs]), and they compare and evaluate a US/UK study analyzing the differences and recommending future strategy. The subject matter expert (SME) consensus guidelines developed for use by the US Army Air Ambulance units commonly known as call sign "DUSTOFF." These TACEVAC assets in Afghanistan were validated in this retrospective study. Using statistical analysis, the authors were able to ascertain that the current DUSTOFF SME-derived guidelines offer a sensitivity of 63.04% and a specificity of 89.07%. By adjusting the indicators to include a single above-ankle amputation with a systolic blood pressure (SBP) less than 90 mmHg and pulse greater than 120/min, the sensitivity could be increased to 67.39% while maintaining the specificity at 89.07%. In our data set, a single amputation above the ankle, in combination with an SBP of less than 100 mmHg and a pulse of greater than 120/min, increased the sensitivity to 76% but with a slight drop in specificity to 86%. Further study of military prehospital casualty data is under way to identify additional physiological parameters that will allow simple scoring tools in the remote setting to guide the administration of prehospital blood products.