title: Time dependent validity in the diagnosis of brain death using transcranial Doppler sonography.
abstract: OBJECTIVE
  To evaluate the validity of transcranial Doppler (TCD) in confirming brain death from various pathological conditions.
  
  
  METHODS
  An observational case-control study over a 2.5 year period, in which transcranial Doppler (TCD) examinations were done on 101 comatose patients for confirmation of brain death. Between October 2002 to May 2005, 44 clinically diagnosed brain death cases (29 male, 15 female; mean (SD) age, 46.5 (19.5) years; Glasgow Coma Scale (GCS) score, 3.0 (0.0)) and 57 controls (36 male, 21 female; age 48.1 (16.5) years; mean GCS, 4.9 (1.7)) were examined. Reverse diastolic flow, very small systolic spikes, or no signals were considered characteristic of cerebral circulatory arrest.
  
  
  RESULTS
  The sensitivity and specificity of TCD examination of both the basilar artery and the middle cerebral arteries (MCAs) in confirming brain death were 77.2% and 100%, respectively. The sensitivity of TCD-diagnosed brain death increased with elapsed time. There was a trend for the basilar artery to have greater sensitivity (86.4% v 77.2%), higher positive predictive value (90.5% v 85.1%), and fewer false negatives (14% v 23.7%) than the MCAs for diagnosing brain death (all NS). The consistency of the basilar artery and the MCAs for diagnosing brain death was significant (kappa=0.877, p<0.001 and kappa=0.793, p<0.001, respectively).
  
  
  CONCLUSIONS
  TCD can be a confirmatory tool for diagnosing brain death. The validity of TCD diagnosed brain death depends on the time lapse between brain death and the performance of TCD. TCD of both the basilar artery and the MCAs showed significant consistency in brain death diagnosis.
authors.affiliation: Department of Neurosurgery, Chi-Mei Medical Centre, Tainan, Taiwan.
authors.forename: J-R
authors.initials: JR
authors.lastname: Kuo
authors.forename: C-F
authors.initials: CF
authors.lastname: Chen
authors.forename: C-C
authors.initials: CC
authors.lastname: Chio
authors.forename: C-H
authors.initials: CH
authors.lastname: Chang
authors.forename: C-C
authors.initials: CC
authors.lastname: Wang
authors.forename: C-M
authors.initials: CM
authors.lastname: Yang
authors.forename: K-C
authors.initials: KC
authors.lastname: Lin
mesh_terms: D000328:Adult; D000368:Aged; D001488:Basilar Artery / Q000000981:diagnostic imaging; D001926:Brain Death / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity; D013997:Time Factors; D017585:Ultrasonography, Doppler, Transcranial