title: A prospective evaluation of platelet function in patients on antiplatelet therapy with traumatic intracranial hemorrhage.
abstract: BACKGROUND
  Platelet transfusion is increasingly used in patients with traumatic intracranial hemorrhage (ICH) on aspirin therapy to minimize the progression of ICH. We hypothesized (null) that platelet transfusion in this cohort of patients does not improve platelet function.
  
  
  METHODS
  We performed a prospective interventional trail on patients with traumatic ICH on daily high-dose (325 mg) aspirin therapy. All patients received one pack of apheresis platelets. Blood samples were collected before and 1 hour after platelet transfusion. Platelet function was assessed using Verify Now Platelet Function Assay, and a cutoff of greater than 550 aspirin reaction units was used to define functioning platelets (FP).
  
  
  RESULTS
  Twenty-eight patients were enrolled in the study. On presentation, 79% (22 of 28) of the patients had nonfunctioning platelets (NFPs), and transfusion of platelets did not improve platelet function as 81% (18 of 22) still had NFP. Of the 22 patients, 4 converted from NFP to FP after transfusion. There was no difference in the progression of ICH (37.5% vs. 30%, p = 0.7) or neurosurgical intervention (12.5% vs. 15%, p = 0.86) between patients with FP and NFP after platelet transfusion.
  
  
  CONCLUSIONS
  Administration of one pack of apheresis platelet did not improve platelet function. In our study, progression of ICH and the need for neurosurgical intervention were independent of platelet function. Further randomized clinical trials are required to assess both the dose dependence effect and role of platelet transfusion in patients on antiplatelet therapy with traumatic ICH.
  
  
  METHODS
  Therapeutic study, level III.
authors.affiliation: From the Division of Trauma, Emergency Surgery, Critical Care, and Burns, Department of Surgery, The University of Arizona, Tucson, Arizona.
authors.forename: Bellal
authors.initials: B
authors.lastname: Joseph
authors.forename: Viraj
authors.initials: V
authors.lastname: Pandit
authors.forename: Moutamn
authors.initials: M
authors.lastname: Sadoun
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Larkins
authors.forename: Narong
authors.initials: N
authors.lastname: Kulvatunyou
authors.forename: Andrew
authors.initials: A
authors.lastname: Tang
authors.forename: Matthew
authors.initials: M
authors.lastname: Mino
authors.forename: Randall S
authors.initials: RS
authors.lastname: Friese
authors.forename: Peter
authors.initials: P
authors.lastname: Rhee
mesh_terms: D000368:Aged; D001792:Blood Platelets / Q000502:physiology*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020198:Intracranial Hemorrhage, Traumatic / Q000097:blood / Q000628:therapy*; D008297:Male; D015539:Platelet Activation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D010979:Platelet Function Tests; D017713:Platelet Transfusion; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors