title: [Validation of transcranial Doppler in the diagnosis of brain death].
abstract: BACKGROUND
  The clinical diagnosis of brain death is complex.
  
  
  OBJECTIVE
  To evaluate the diagnostic accuracy of transcranial Doppler (TCD) for brain death.
  
  
  METHODS
  Patients seen on the intensive care unit of a private hospital between January 2004 to December 2008, were included if they were in structural coma, had no craniectomy and had a blind evaluation by a neurologist and TCD done in less than three hours. The diagnosis of brain death was based on a clinical evaluation that considered the absence of sedative drugs, median blood pressure>60 mmHg, body temperature over 35 masculine Celsius and complete absence of brainstem reflexes. An expert neurosonologist, with a TCD-PMD-100, 2 Mhz transducer, used an institutional protocol that considers the examination as positive for brain circulatory arrest when there is presence of reverberating, small systolic peaks or the disappearance of a previous signal present on both middle cerebral arteries and intracranial vertebral arteries.
  
  
  RESULTS
  Fifty three patients were evaluated, 25 with clinical brain death. On 45 cases (84.9%), the interval between both evaluations was less than one hour. The sensitivity, specificity, positive and negative predictive values for the diagnosis of brain death with TCD were 100, 96, 96.1 and 100% respectively. Positive and negative likelihood ratios for brain death were 28 and 0, respectively.
  
  
  CONCLUSIONS
  TCD is a valid and useful technique for the diagnosis of brain death and can be used on complicated cases.
authors.affiliation: Unidad de Tratamiento del Ataque Cerebrovascular, Servicio de Neurología, Departamento de Medicina, Clínica Alemana de Santiago, Chile. abrunser2002@yahoo.com
authors.forename: Alejandro
authors.initials: A
authors.lastname: Brunser
authors.forename: Arnold
authors.initials: A
authors.lastname: Hoppe
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Cárcamo
authors.forename: Pablo M
authors.initials: PM
authors.lastname: Lavados
authors.forename: Andrés
authors.initials: A
authors.lastname: Roldán
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Rivas
authors.forename: Marcela
authors.initials: M
authors.lastname: Valenzuela
authors.forename: José Miguel
authors.initials: JM
authors.lastname: Montes
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001926:Brain Death / Q000000981:diagnostic imaging*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D017585:Ultrasonography, Doppler, Transcranial / Q000592:standards*; D014711:Vertebral Artery / Q000000981:diagnostic imaging; D055815:Young Adult