title: Acquired coagulopathy of traumatic brain injury defined by routine laboratory tests: which laboratory values matter?
abstract: BACKGROUND
  Coagulopathy is a major determinant of disability and death in patients with traumatic intracranial hemorrhage. However, the correlation between coagulopathy defined by routine coagulation tests and clinical outcomes in traumatic brain injury (TBI) is not well defined. The aim of our study was to determine the effect of coagulopathy diagnosed by routine laboratory tests on outcomes in TBI patients.
  
  
  METHODS
  We performed a retrospective cohort analysis of all isolated TBI patients exclusive of prehospital antiplatelet and anticoagulants with coagulation tests, namely, international normalized ratio (INR), platelet count, and partial thromboplastin time at admission. We defined coagulopathy by an INR of 1.5 or greater, partial thromboplastin time of 35 or greater, or platelet count of 100 × 10(3)/µL or less. Outcome measures were progression on repeat head computed tomography (RHCT), need for neurosurgical intervention, and mortality.
  
  
  RESULTS
  A total of 591 patients were enrolled, with a mean (SD) age of 47.4 (26.5) years and 67% being male. Of the patients, 13.3% were coagulopathic at admission. Platelet count of 100 × 10(3)/µL or less was an independent predictor of progression on RHCT (odd ratio [OR], 4; 95% confidence interval [CI], 1.7-10), need for neurosurgical intervention (OR, 3.6; 95% CI, 1.2-6.1), and mortality (OR, 2.6; 95% CI, 1.1-4.8). INR was an independent predictor of progression on RHCT (OR, 2; 95% CI, 1.1-4.3).
  
  
  CONCLUSIONS
  Routine bedside coagulation parameters at admission play an important role in predicting outcomes in blunt TBI. Platelet count is the strongest predictor for progression of initial insult on RHCT, need for neurosurgical intervention, and mortality.
  
  
  METHODS
  Prognostic study, level III.
authors.affiliation: From the Division of Trauma, Critical Care, Emergency Surgery, and Burns, The University of Arizona, College of Medicine, Tucson, Arizona.
authors.forename: Bellal
authors.initials: B
authors.lastname: Joseph
authors.forename: Hassan
authors.initials: H
authors.lastname: Aziz
authors.forename: Bardiya
authors.initials: B
authors.lastname: Zangbar
authors.forename: Narong
authors.initials: N
authors.lastname: Kulvatunyou
authors.forename: Viraj
authors.initials: V
authors.lastname: Pandit
authors.forename: Terence
authors.initials: T
authors.lastname: O'Keeffe
authors.forename: Andrew
authors.initials: A
authors.lastname: Tang
authors.forename: Julie
authors.initials: J
authors.lastname: Wynne
authors.forename: Randall S
authors.initials: RS
authors.lastname: Friese
authors.forename: Peter
authors.initials: P
authors.lastname: Rhee
mesh_terms: D001778:Blood Coagulation Disorders / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality; D001930:Brain Injuries / Q000150:complications / Q000175:diagnosis* / Q000401:mortality; D003955:Diagnostic Tests, Routine / Q000706:statistics & numerical data; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D010314:Partial Thromboplastin Time; D010976:Platelet Count; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D014193:Trauma Centers / Q000706:statistics & numerical data