title: Fast Doppler as a novel bedside measure of cerebral perfusion in preterm infants.
abstract: BACKGROUND
  Altered cerebral perfusion from impaired autoregulation may contribute to the morbidity and mortality associated with premature birth. We hypothesized that fast Doppler imaging could provide a reproducible bedside estimation of cerebral perfusion and autoregulation in preterm infants.
  
  
  METHODS
  This is a prospective pilot study using fast Doppler ultrasound to assess blood flow velocity in the basal ganglia of 19 subjects born at 26-32 wk gestation. Intraclass correlation provided a measure of test-retest reliability, and linear regression of cerebral blood flow velocity and heart rate or blood pressure allowed for estimations of autoregulatory ability.
  
  
  RESULTS
  The intraclass correlation when imaging in the first 48 h of life was 0.634. We found significant and independent correlations between the systolic blood flow velocity and both systolic blood pressure and heart rate (P = 0.015 and 0.012 respectively) only in the 26-28 wk gestational age infants in the first 48 h of life.
  
  
  CONCLUSIONS
  Our results suggest that fast Doppler provides reliable bedside measurements of cerebral blood flow velocity at the tissue level in premature infants, acting as a proxy for cerebral tissue perfusion. Additionally, autoregulation appears to be impaired in the extremely preterm infants, even within a normal range of blood pressures.
authors.affiliation: Department of Pediatrics, University of Washington, Seattle, Washington.
authors.forename: Eric S
authors.identifier: http://orcid.org/0000-0002-2892-2678
authors.initials: ES
authors.lastname: Peeples
authors.affiliation: Department of Neurological Surgery, University of Washington, Seattle, Washington.
authors.forename: Edin
authors.initials: E
authors.lastname: Mehic
authors.affiliation: Department of Neurological Surgery, University of Washington, Seattle, Washington.|Division of Engineering and Mathematics, University of Washington, Seattle, Washington.
authors.forename: Pierre D
authors.initials: PD
authors.lastname: Mourad
authors.affiliation: Department of Pediatrics, University of Washington, Seattle, Washington.
authors.forename: Sandra E
authors.identifier: http://orcid.org/0000-0002-6861-6229
authors.initials: SE
authors.lastname: Juul
mesh_terms: D001783:Blood Flow Velocity; D001794:Blood Pressure; D002560:Cerebrovascular Circulation; D005865:Gestational Age; D006339:Heart Rate; D006706:Homeostasis; D006801:Humans; D062071:Infant, Extremely Premature; D007231:Infant, Newborn; D016014:Linear Models; D010865:Pilot Projects; D000067716:Point-of-Care Testing; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D018615:Ultrasonography, Doppler, Color; D017585:Ultrasonography, Doppler, Transcranial