title: Early platelet transfusion improves platelet activity and may improve outcomes after intracerebral hemorrhage.
abstract: BACKGROUND
  In patients with acute intracerebral hemorrhage (ICH), reduced platelet activity on admission predicts hemorrhage growth and poor outcomes. We tested the hypotheses that platelet transfusion improves measured platelet activity. Further, we hypothesized that earlier treatment in patients at high risk for hemorrhage growth and poor outcome would reduce follow-up hemorrhage size and poor clinical outcomes.
  
  
  METHODS
  We prospectively identified consecutive patients with ICH who had reduced platelet activity on admission and received a platelet transfusion. We defined high-risk patients as per a previous publication, reduced platelet activity, or known anti-platelet therapy (APT) and the diagnostic CT within 12 h of symptom onset. Platelet activity was measured with the VerifyNow-ASA (Accumetrics, CA), ICH volumes on CT with computerized quantitative techniques, and functional outcomes with the modified Rankin Scale (mRS) at 3 months.
  
  
  RESULTS
  Forty-five patients received a platelet transfusion with an increase in platelet activity from 472 ± 50 (consistent with an aspirin effect) to 561 ± 92 aspirin reaction units (consistent with no aspirin effect, P < 0.001). For high-risk patients, platelet transfusion within 12 h of symptom onset, as opposed to >12 h, was associated with smaller follow-up hemorrhage size (8.4 [3-17.4] vs. 13.8 [12.3-62.5] ml, P = 0.04) and increased odds of independence (mRS < 4) at 3 months (11 of 20 vs. 0 of 7, P = 0.01). There were similar results for patients with known APT.
  
  
  CONCLUSIONS
  In patients at high risk for hemorrhage growth and poor outcome, early platelet transfusion improved platelet activity assay results and was associated with smaller final hemorrhage size and more independence at 3 months.
authors.affiliation: Department of Neurology, Northwestern University's Feinberg School of Medicine, Chicago, IL 60611, USA. a-naidech@northwestern.edu
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Naidech
authors.forename: Storm M
authors.initials: SM
authors.lastname: Liebling
authors.forename: Neil F
authors.initials: NF
authors.lastname: Rosenberg
authors.forename: Paul F
authors.initials: PF
authors.lastname: Lindholm
authors.forename: Richard A
authors.initials: RA
authors.lastname: Bernstein
authors.forename: H Hunt
authors.initials: HH
authors.lastname: Batjer
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Alberts
authors.forename: Hau C
authors.initials: HC
authors.lastname: Kwaan
mesh_terms: D000368:Aged; D002543:Cerebral Hemorrhage / Q000097:blood / Q000628:therapy*; D016638:Critical Illness / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015539:Platelet Activation / Q000502:physiology*; D017713:Platelet Transfusion / Q000009:adverse effects / Q000379:methods*; D011446:Prospective Studies; D012306:Risk; D012720:Severity of Illness Index; D016896:Treatment Outcome