title: Transcranial Doppler for predicting delayed cerebral ischemia after subarachnoid hemorrhage.
abstract: OBJECTIVE
  Transcranial Doppler (TCD) is widely used to monitor the temporal course of vasospasm after subarachnoid hemorrhage (SAH), but its ability to predict clinical deterioration or infarction from delayed cerebral ischemia (DCI) remains controversial. We sought to determine the prognostic utility of serial TCD examination after SAH.
  
  
  METHODS
  We analyzed 1877 TCD examinations in 441 aneurysmal SAH patients within 14 days of onset. The highest mean blood flow velocity (mBFV) value in any vessel before DCI onset was recorded. DCI was defined as clinical deterioration or computed tomographic evidence of infarction caused by vasospasm, with adjudication by consensus of the study team. Logistic regression was used to calculate adjusted odds ratios for DCI risk after controlling for other risk factors.
  
  
  RESULTS
  DCI occurred in 21% of patients (n = 92). Multivariate predictors of DCI included modified Fisher computed tomographic score (P = 0.001), poor clinical grade (P = 0.04), and female sex (P = 0.008). After controlling for these variables, all TCD mBFV thresholds between 120 and 180 cm/s added a modest degree of incremental predictive value for DCI at nearly all time points, with maximal sensitivity by SAH day 8. However, the sensitivity of any mBFV more than 120 cm/s for subsequent DCI was only 63%, with a positive predictive value of 22% among patients with Hunt and Hess grades I to III and 36% in patients with Hunt and Hess grades IV and V. Positive predictive value was only slightly higher if mBFV exceeded 180 cm/s.
  
  
  CONCLUSIONS
  Increased TCD flow velocities imply only a mild incremental risk of DCI after SAH, with maximal sensitivity by day 8. Nearly 40% of patients with DCI never attained an mBFV more than 120 cm/s during the course of monitoring. Given the poor overall sensitivity of TCD, improved methods for identifying patients at high risk for DCI after SAH are needed.
authors.affiliation: Neurological Intensive Care Unit, Departments of Neurology and Neurosurgery, Columbia University, New York, New York 10032, USA.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Carrera
authors.forename: J Michael
authors.initials: JM
authors.lastname: Schmidt
authors.forename: Mauro
authors.initials: M
authors.lastname: Oddo
authors.forename: Luis
authors.initials: L
authors.lastname: Fernandez
authors.forename: Jan
authors.initials: J
authors.lastname: Claassen
authors.forename: David
authors.initials: D
authors.lastname: Seder
authors.forename: Kiwon
authors.initials: K
authors.lastname: Lee
authors.forename: Neeraj
authors.initials: N
authors.lastname: Badjatia
authors.forename: E Sander
authors.initials: ES
authors.lastname: Connolly
authors.forename: Stephan A
authors.initials: SA
authors.lastname: Mayer
mesh_terms: D000368:Aged; D001921:Brain / Q000098:blood supply / Q000503:physiopathology; D002545:Brain Ischemia / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000517:prevention & control; D002536:Cerebral Arteries / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D013345:Subarachnoid Hemorrhage / Q000150:complications*; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods* / Q000706:statistics & numerical data; D020301:Vasospasm, Intracranial / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000517:prevention & control