title: Is bilateral monitoring of cerebral oxygen saturation necessary during neonatal aortic arch reconstruction?
abstract: In this study, we measured cerebral oxygenation in both cerebral hemispheres by using near-infrared spectroscopy before, during, and after regional low-flow cerebral perfusion (RLFP) to determine whether bilateral monitoring was necessary. Neonates undergoing aortic arch reconstruction with RLFP were studied. The bilateral regional cerebral oxygenation index was measured and recorded at 1-min intervals during the following periods: 1) before bypass, 2) during bypass before RLFP, 3) during RLFP, 4) on bypass after RLFP, and 5) post-bypass. Before bypass and on bypass before RLFP, the correlation (r = 0.979 and 0.852) and agreement (mean bias, right versus left, 0 and +2) between hemispheres were excellent. During RLFP, however, correlation (r = 0.35) and agreement (mean bias of the right versus left side, +6.3) worsened and only partially returned to baseline values after RLFP. Nine of 19 patients had sustained differences in cerebral oxygen saturation of >10%, always with the left side values less than the right. Bilateral monitoring detects desaturation in the left cerebral hemisphere during RLFP. The long-term consequences of lower saturations on the left side of the brain are unclear.
  
  
  CONCLUSIONS
  Left-sided cerebral hemisphere oxygen saturation, measured with near-infrared spectroscopy, was less than right-sided cerebral oxygen saturation during regional low-flow cerebral perfusion used for neonatal aortic arch reconstruction.
authors.affiliation: Department of Anesthesiology, Baylor College of Medicine, and Division of Pediatric Cardiovascular Anesthesiology, Texas Children's Hospital, Houston, Texas 77030, USA. dra@bcm.tmc.edu
authors.forename: Dean B
authors.initials: DB
authors.lastname: Andropoulos
authors.forename: Laura K
authors.initials: LK
authors.lastname: Diaz
authors.forename: Charles D
authors.initials: CD
authors.lastname: Fraser
authors.forename: E Dean
authors.initials: ED
authors.lastname: McKenzie
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Stayer
mesh_terms: D001013:Aorta, Thoracic / Q000601:surgery*; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000502:physiology; D016343:Monitoring, Intraoperative; D010101:Oxygen Consumption / Q000502:physiology*; D010477:Perfusion; D011138:Polytetrafluoroethylene; D019651:Plastic Surgery Procedures; D012984:Software; D019265:Spectroscopy, Near-Infrared; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D011138:Polytetrafluoroethylene