title: Monitoring Cerebral Autoregulation After Subarachnoid Hemorrhage.
abstract: Delayed cerebral ischemia (DCI) is a major contributor to morbidity and mortality after subarachnoid hemorrhage (SAH). Data challenge vasospasm being the sole cause of ischemia and suggest other factors. We tested the hypothesis that early autoregulatory failure might predict DCI.
  
  
  
  This is a prospective observational study of cerebral autoregulation following SAH in which the primary end point was DCI at 21 days. Cox proportional hazards and multivariate models were used and the benefit of using multiple indices was analyzed.
  
  
  
  Ninety-eight patients were included in the study. There was an increased risk of DCI with early dysautoregulation (odds ratio [OR]: 7.46, 95% confidence interval [CI]: 3.03-18.40 and OR: 4.52, 95 % CI: 1.84-11.07 for the transcranial Doppler index of autoregulation [Sxa] and near-infrared spectroscopy index of autoregulation [TOxa], respectively), but not vasospasm (OR: 1.36, 95 % CI: 0.56-3.33). Sxa and TOxa remained independent predictors of DCI in the multivariate model (OR: 12.66, 95 % CI: 2.97-54.07 and OR: 5.34, 95 % CI: 1.25-22.84 for Sxa and TOxa, respectively). There was good agreement between different indices. All 13 patients with impaired autoregulation in all three methods developed DCI.
  
  
  
  Disturbed autoregulation in the first 5 days after SAH is predictive of DCI. Although colinearities exist between the methods assessed, multimodal monitoring of cerebral autoregulation can aid the prediction of DCI.
authors.affiliation: Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Box 167, Block A, Hills Road, CB2 0QQ, Cambridge, UK. kpb26@cam.ac.uk.|Department of Neurosurgery, Medical Centre for Postgraduate Education, Mazovia Brodno Hospital, Warsaw, Poland. kpb26@cam.ac.uk.
authors.forename: Karol P
authors.initials: KP
authors.lastname: Budohoski
authors.affiliation: Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.
authors.forename: Marek
authors.initials: M
authors.lastname: Czosnyka
authors.affiliation: Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Smielewski
authors.affiliation: Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Box 167, Block A, Hills Road, CB2 0QQ, Cambridge, UK.
authors.forename: Georgios V
authors.initials: GV
authors.lastname: Varsos
authors.affiliation: Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Box 167, Block A, Hills Road, CB2 0QQ, Cambridge, UK.|Institute of Biomedical Engineering and Instrumentation, Wroclaw University of Technology, Wroclaw, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Kasprowicz
authors.affiliation: Department of Anesthesiology, Texas Children's Hospital, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Ken M
authors.initials: KM
authors.lastname: Brady
authors.affiliation: Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Box 167, Block A, Hills Road, CB2 0QQ, Cambridge, UK.
authors.forename: John D
authors.initials: JD
authors.lastname: Pickard
authors.affiliation: Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Box 167, Block A, Hills Road, CB2 0QQ, Cambridge, UK.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Kirkpatrick
mesh_terms: D019540:Area Under Curve; D002545:Brain Ischemia / Q000209:etiology / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D008991:Monitoring, Physiologic; D015999:Multivariate Analysis; D016017:Odds Ratio; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012372:ROC Curve; D018570:Risk Assessment; D019265:Spectroscopy, Near-Infrared; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D017585:Ultrasonography, Doppler, Transcranial; D020301:Vasospasm, Intracranial / Q000209:etiology / Q000503:physiopathology*
keywords: Cerebral autoregulation; Delayed cerebral ischemia; Near-infrared spectroscopy; Prediction; Subarachnoid hemorrhage; Transcranial Doppler