title: Early identification of patients at risk for symptomatic vasospasm after aneurysmal subarachnoid hemorrhage.
abstract: OBJECTIVE
  To develop a scheme for early identification of individuals at risk for symptomatic vasospasm after subarachnoid hemorrhage (SAH).
  
  
  METHODS
  Analysis of prospectively collected data from the placebo-treated group in a multicenter clinical trial.
  
  
  METHODS
  Fifty-four neurosurgical centers in North America.
  
  
  RESULTS
  We identified independent predictors of symptomatic vasospasm using stepwise logistic regression analysis from demographic, clinical, laboratory, and neuroimaging characteristics of the participants. We developed a scoring system (symptomatic vasospasm risk index) based on a combination of these predictors. Out of 283 patients in the analysis (all treated with oral nimodipine), 93 (33%) developed symptomatic vasospasm within 14 days after SAH. There were four independent predictors of symptomatic vasospasm: thickness of subarachnoid clot on computed tomographic scan (odds ratio [OR], 4.1; 95% confidence interval [CI], 1.8-10.0); early rise in middle cerebral artery mean flow velocity (MCA-MFV), defined as a value > or =110 cm/sec recorded on or before post-SAH day 5 (OR, 1.9; 95% CI, 1.1-3.3), Glasgow Coma Scale score <14 (OR, 1.8; 95% CI, 1.1-3.1); and rupture of anterior cerebral or internal carotid artery aneurysm (OR, 1.9; 95% CI, 1.0-3.4). The probability of identifying patients who would develop symptomatic vasospasm (percentage of area under receiver operating characteristics curve +/- SEM) was higher with symptomatic vasospasm risk index (68%+/-8%) compared with thickness of clot (62%+/-8%; p = .08) or MCA-MFV (45%+/-7%, p < .05) criteria alone.
  
  
  CONCLUSIONS
  Patients at high risk for symptomatic vasospasm can be identified early in the course of SAH using a risk index. A risk index based on a combination of variables may represent a predictive paradigm superior to conventionally used criteria based on clot thickness or MCA-MFV criteria.
authors.affiliation: Division of Neurosciences Critical Care, The Johns Hopkins Medical Institutions, Baltimore, Maryland, USA.
authors.forename: A I
authors.initials: AI
authors.lastname: Qureshi
authors.forename: G Y
authors.initials: GY
authors.lastname: Sung
authors.forename: A Y
authors.initials: AY
authors.lastname: Razumovsky
authors.forename: K
authors.initials: K
authors.lastname: Lane
authors.forename: R N
authors.initials: RN
authors.lastname: Straw
authors.forename: J A
authors.initials: JA
authors.lastname: Ulatowski
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000175:diagnosis*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009656:North America; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000175:diagnosis*; D013997:Time Factors; D020301:Vasospasm, Intracranial / Q000175:diagnosis* / Q000209:etiology