Platelet Transfusion and Repeat TEG-PM in Patients With Severe TBI on Antiplatelet Therapy (Repeat TEG-PM)

Inclusion Criteria for Interventional Portion of Study: * Patients ≥ 18 years of age who present with TICH meeting Brain Injury Guidelines (BIG) 2 or 3 head bleed criteria * Currently on antiplatelet medication on admission * Must have taken this antiplatelet medication within the past 48 hours prior to presentation * Patients who have AA and/or ADP inhibition of 70% or greater and Maximum Amplitude (MA) \<50 will then receive a platelet transfusion and a repeat TEG-PM 1hr after transfusion Exclusion Criteria for Interventional Portion of Study: * Under 18 years of age * Have a known bleeding diatheses * Current therapeutic anticoagulation use * Do not know the time of their last antiplatelet medication dose * Patients or their proxy who are unable to provide consent * Patients with concomitant long bone fractures or solid organ injuries Inclusion Criteria for Retrospective Portion of Study: • Patients with a TICH who are 18 years of age or older Exclusion Criteria for Retrospective Portion of Study: * Abbreviated Injury Scale (AIS) \>1 in body regions other than head because of concomitant long bone fracture or solid organ injury * Under 18 years of age