Not all head injured patients on antiplatelet drugs need platelets: Integrating platelet reactivity testing into platelet transfusion guidelines.

Introduction: Antiplatelet medication use continues to rise in an aging population, and these agents can have a deleterious effect for patients with traumatic intracranial hemorrhage (tICH). The purpose of the current investigation is to assess the safety and efficacy of using platelet reactivity testing (PRT) to direct platelet transfusion for tICH patients.

Patients And Methods: A Level I trauma center adopted a targeted platelet transfusion guideline using PRT to determine whether platelets were inhibited by an antiplatelet medication (aspirin or P2Y12 inhibitors). Non-inhibited patients were monitored without platelet transfusion, regardless of severity of the head injury. The guideline was analyzed retrospectively to evaluate patient outcomes during the study period (June 2014-December 2016). All patients sustained blunt tICH and received a PRT for known or suspected antiplatelet medication use. Differences were assessed with Kruskal-Wallis and Fisher's Exact tests.

Results: 166 patients met study inclusion criteria. PRT results indicated that 48 patients (29%) were not inhibited by an antiplatelet medication, and 92% of those patients (n = 44) were spared platelet transfusion. Seven percent (n = 11) of all patients had a clinically significant progression of the head bleed, but this did not differ by inhibition or transfusion status. Implementation of this guideline reduced platelet transfusions by an estimated 30-50% and associated healthcare costs by 42%.

Conclusions: A targeted platelet transfusion guideline using PRT reduced platelet usage for patients with tICH. If appropriately tested, results suggest that not all tICH patients taking or suspected of taking antiplatelet drugs need platelet transfusion. Platelet reactivity testing can significantly reduce healthcare costs and resource usage.