title: Cerebral autoregulation in the preterm newborn using near-infrared spectroscopy: a comparison of time-domain and frequency-domain analyses.
abstract: The aim was to compare two conventional methods used to describe cerebral autoregulation (CA): frequency-domain analysis and time-domain analysis. We measured cerebral oxygenation (as a surrogate for cerebral blood flow) and mean arterial blood pressure (MAP) in 60 preterm infants. In the frequency domain, outcome variables were coherence and gain, whereas the cerebral oximetry index (COx) and the regression coefficient were the outcome variables in the time domain. Correlation between coherence and COx was poor. The disagreement between the two methods was due to the MAP and cerebral oxygenation signals being in counterphase in three cases. High gain and high coherence may arise spuriously when cerebral oxygenation decreases as MAP increases; hence, time-domain analysis appears to be a more robust—and simpler—method to describe CA.
authors: Copenhagen University Hospital-Rigshospitalet, Department of Neonatology, Blegdamsvej 9, 2100 Copenhagen, DenmarkbUniversity of Copenhagen, Faculty of Health and Medical Sciences, Blegdamsvej 3, Copenhagen, Denmark.
authors: Vibeke R
authors: VR
authors: Eriksen
authors: Copenhagen University Hospital-Rigshospitalet, Department of Neonatology, Blegdamsvej 9, 2100 Copenhagen, DenmarkcCopenhagen University Hospital-Rigshospitalet, Department of Paediatrics and Adolescent Medicine, Blegdamsvej 9, Copenhagen, Denmark.
authors: Gitte H
authors: GH
authors: Hahn
authors: Copenhagen University Hospital-Rigshospitalet, Department of Neonatology, Blegdamsvej 9, 2100 Copenhagen, Denmark.
authors: Gorm
authors: G
authors: Greisen
mesh_terms: D062186:Arterial Pressure / Q000502:physiology; D001921:Brain / Q000502:physiology*; D002560:Cerebrovascular Circulation; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007427:Intracranial Pressure / Q000502:physiology; D010092:Oximetry; D010101:Oxygen Consumption / Q000502:physiology*; D019265:Spectroscopy, Near-Infrared