title: Intracranial bleeds after minor and minimal head injury in patients on warfarin.
abstract: BACKGROUND
  There is little evidence to guide physicians on management of patients who sustain head injuries while on warfarin.
  
  
  OBJECTIVE
  Our objective was to determine the rate of intracranial bleeding in anticoagulated patients with minor and minimal head injuries and the association with clinical features and international normalized ratio (INR).
  
  
  METHODS
  We conducted a historical cohort study of adult patients, taking warfarin, at two tertiary care emergency departments over 2 years with minor (Glasgow Coma Score 13-15, with loss of consciousness, amnesia, or confusion) or minimal (Glasgow Coma Score 15 without loss of consciousness, amnesia, or confusion) head injuries. Patients with penetrating injuries, INR < 1.5, or a new focal neurological deficit were excluded. Our outcome, intracranial bleeding, was determined by the radiologist's final computed tomography (CT) report for imaging performed within 2 weeks.
  
  
  RESULTS
  There were 176 patients enrolled, of which 157 (89.2%) had CT and 28 (15.9%) had intracranial bleeding. Comparing patients with and without intracranial bleeding found no significant differences in INR, and loss of consciousness was associated with higher rate of intracranial bleeding. The rate of intracranial bleeding in the minor and minimal head injury groups was 21.9% and 4.8%, respectively.
  
  
  CONCLUSIONS
  The rate of intracranial bleeding in patients on warfarin is considerable. Loss of consciousness is associated with high rates of intracranial bleeding. This study supports a low threshold for ordering CT scans for anticoagulated patients with head injuries.
authors.affiliation: Department of Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Khaled N
authors.initials: KN
authors.lastname: Alrajhi
authors.affiliation: Department of Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Perry
authors.affiliation: Department of Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Forster
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects*; D015331:Cohort Studies; D006259:Craniocerebral Trauma / Q000150:complications* / Q000000981:diagnostic imaging; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D020300:Intracranial Hemorrhages / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D014859:Warfarin / Q000009:adverse effects*
chemical_list: D000925:Anticoagulants; D014859:Warfarin
keywords: anticoagulants; intracranial hemorrhages; minor head injury