title: Intraoperative Cerebral Autoregulation Assessment Using Ultrasound-Tagged Near-Infrared-Based Cerebral Blood Flow in Comparison to Transcranial Doppler Cerebral Flow Velocity: A Pilot Study.
abstract: OBJECTIVE
  This was a pilot study comparing the ability of a new ultrasound-tagged near-infrared (UT-NIR) device to detect cerebral autoregulation (CA) in comparison to transcranial Doppler (TCD).
  
  
  METHODS
  An unblinded, prospective, clinical feasibility study.
  
  
  METHODS
  Tertiary-care university hospital cardiac surgical operating rooms.
  
  
  METHODS
  Twenty adult patients undergoing cardiac surgery with cardiopulmonary bypass (CPB).
  
  
  METHODS
  There were no clinical interventions based on study monitoring devices, but a continuous correlation analysis of digital data from transcranial Doppler (TCD) velocity was compared with a novel UT-NIR device and correlation analysis of change signals versus mean arterial pressure was performed in order to detect presence or absence of intact CA and for determination of the lower limit of cerebral autoregulation during CPB.
  
  
  RESULTS
  Similar and highly significant concordance (κ = 1.00; p<0.001) was demonstrated between the 2 methodologies for determination of CA, indicating good correlation between the 2 methodologies. Intact CA was absent in 2 patients during CPB, and both devices were able to detect this.
  
  
  CONCLUSIONS
  To the authors' knowledge this is the first clinical report of a UT-NIR device that shows promise as a clinically useful modality for detection of CA and the lower limit of cerebral autoregulation. The utility of UT-NIR was demonstrated further during times at which extensive usage of electrocautery or functional absence of the transcranial window rendered TCD uninterpretable.
authors.affiliation: Department of Anesthesiology and Perioperative Medicine, Schulich School of Medicine, University of Western Ontario, London, Canada. Electronic address: john.murkin@lhsc.on.ca.
authors.forename: John M
authors.initials: JM
authors.lastname: Murkin
authors.affiliation: Ornim Medical, Kfar Saba, Israel.
authors.forename: Moshe
authors.initials: M
authors.lastname: Kamar
authors.affiliation: Ornim Medical, Kfar Saba, Israel.
authors.forename: Zmira
authors.initials: Z
authors.lastname: Silman
authors.affiliation: Ornim Medical, Kfar Saba, Israel.
authors.forename: Michal
authors.initials: M
authors.lastname: Balberg
authors.affiliation: Department of Anesthesiology and Perioperative Medicine, Schulich School of Medicine, University of Western Ontario, London, Canada.
authors.forename: Sandra J
authors.initials: SJ
authors.lastname: Adams
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005240:Feasibility Studies; D005260:Female; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D010865:Pilot Projects; D011446:Prospective Studies; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*
keywords: CBF; CPB; TCD; UT-NIR; cardiopulmonary bypass; cerebral autoregulation; cerebral blood flow; transcranial Doppler; ultrasound-tagged near-infrared device