G. R. Stettler1, H. B. Moore1, G. R. Nunns1, A. Sauaia1, A. Ghasabyan2, C. C. Silliman1,3,4, A. Banerjee1, E. E. Moore1,2 1University Of Colorado Denver,Department Of Surgery,Aurora, CO, USA 2Denver Health Medical Center,Department Of Surgery,Aurora, CO, USA 3Bonfils Blood Center,Denver, CO, USA 4Children’s Hospital Colorado,Aurora, CO, USA
Introduction: Platelet dysfunction has been documented early after trauma, but the impact on outcome has not been determined. A recent randomized trial of blood component therapy did not document a survival advantage of early platelet transfusion. Our experimental work suggests metabolites generated during shock inhibit platelet function. Our previous clinical work suggested inhibition to adenosine diphosphate (ADP) was a more sensitive marker of trauma induced platelet dysfunction than arachidonic acid. We hypothesize that platelet function assessment via the ADP response will be associated with platelet transfusion but platelet count will be a superior predictor of massive transfusion.
Methods: Subjects without coagulation-related comorbidities or medications were enrolled from 2014-16. Thromboelastography (TEG) Platelet Mapping was assessed in trauma activation patients (TAP, n=270, field or ED arrival blood samples) and healthy volunteers (n=89). Values of MA-ADP (mm) and ADP receptor inhibition (%ADP-INH) presented as median, IQR or n,%. The results of the platelet assessment was not known to the physicians managing the patient, who based their decision for platelet transfusion based on rTEG MA.
Results:Compared to controls, TAP patients showed early low MA-ADP [59, 53-65, vs. 36, 17-50] and higher %ADP-INH [40, 23-69, vs. 4, 0-14] (p<0.0001). MA-ADP and %ADP-INH were both significantly (all p<0.05) correlated with NISS (Spearman Rho: -0.37, +0.26), temperature (Rho=+0.18, -0.14), GCS (Rho=+0.24, -0.20), and platelet count (Rho=+0.21, -0.16). %ADP-INH was higher in blunt trauma compared to penetrating (47, 23-81 vs. 36, 22-60; p=0.03). Adjusted for platelet count, MA-ADP predicted massive transfusion (MT=>10PRBC or death/6hrs, p=0.02), while %ADP-INH did not (p=0.16). Adjusted for platelet count, MA-ADP and %ADP-INH predicted platelet transfusion requirements. Platelet count remained a powerful predictor of MT (p<0.0001). Platelet count is a powerful predictor of MT or death within 6 hours (AUC 0.84), ventilator free days <3 (AUC 0.69), ICU free days <6 (AUC 0.63), death within 24 hours (AUC 0.82), and requirements for platelet transfusions (AUC 0.75). Platelet count was a better predictor of need for MT or death in the first 6 hours compared to %ADP-INH (AUC 0.66; p=0.037) (Fig).
Conclusion:%ADP-INH predicts the need for platelet transfusion, but not for massive transfusion. Compared to platelet function, platelet count is consistently a better predictor of post injury outcomes. The predictive value of dysfunction at the ADP receptor is improved by adjustment for total platelet count.
