title: Transcranial Doppler ultrasonography to confirm brain death: a meta-analysis.
abstract: OBJECTIVE
  Barbiturate therapy or hypothermia precludes proper diagnosis of brain death either clinically or by EEG. Specific intracranial flow patterns indicating cerebral circulatory arrest (CCA) can be visualized by transcranial Doppler ultrasonography (TCD). The aim of this study was to assess the validity of TCD in confirming brain death.
  
  
  METHODS
  Meta-analysis of studies assessing the validity of TCD in confirming brain death.
  
  
  METHODS
  A systematic review of articles in English on the diagnosis brain death by TCD, published between 1980 and 2004, was performed. An oscillating or reverberating flow and systolic spikes were considered to be compatible with CCA. The quality of each study was assessed using standardized methodological criteria. The literature was searched for any article reporting a false-positive result.
  
  
  RESULTS
  Two high-quality and eight low-quality studies were included. Meta-analysis of the two high-quality studies showed a sensitivity of 95% (95% CI 92-97%) and a specificity of 99% (95% CI 97-100%) to detect brain death. Meta-analysis of all ten studies showed a sensitivity of 89% and a specificity of 99%. In the literature we found two false-positive results; however, in both patients brain-stem function did show brain death shortly thereafter.
  
  
  CONCLUSIONS
  CCA by TCD in the anterior and posterior circulation predicted fatal brain damage in all patients; therefore, TCD can be used to determine the appropriate moment for angiography. Further research is needed to demonstrate that CCA by TCD on repeated examination can also predict brain death in all patients.
authors.affiliation: Department of Pediatric Intensive Care, University Medical Center Utrecht, Utrecht, AB, The Netherlands.
authors.forename: Louisa M
authors.initials: LM
authors.lastname: Monteiro
authors.forename: Casper W
authors.initials: CW
authors.lastname: Bollen
authors.forename: Alexander C
authors.initials: AC
authors.lastname: van Huffelen
authors.forename: Rob G A
authors.initials: RG
authors.lastname: Ackerstaff
authors.forename: Nicolaas J G
authors.initials: NJ
authors.lastname: Jansen
authors.forename: Adrianus J
authors.initials: AJ
authors.lastname: van Vught
mesh_terms: D001926:Brain Death / Q000175:diagnosis / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation; D004569:Electroencephalography; D005189:False Positive Reactions; D006801:Humans; D012680:Sensitivity and Specificity; D017585:Ultrasonography, Doppler, Transcranial