Neonatal cerebral Doppler: Arterial and venous flow velocity measurements using color and pulsed Doppler system

Objective: To contribute to the establishment of reference values of blood flow velocity assessed by cerebral Doppler in healthy infants related to gestational age and birth weight during the first week of life. Methods: Five arteries and three veins were evaluated respectively in 120 (74 premature) newborns and in 100 (70 preterm) infants. In a quarter of the latter three recordings at 5-minute intervals were made to assess reproducibility. The relation between flow measurements and gestational age was assessed by linear regression, means by analysis of variance (or Kruskall-Wallis test) and paired samples by Student's t test. Results: There was a significant increase of arterial velocities with increasing gestational age and birth weight, but not for venous velocities. Significant higher values were found in the internal carotid artery followed by the medium cerebral artery. The venous velocities were highly reproducible and the main patterns observed were bandlike and sinusoid type. Conclusion: The knowledge of normal cerebrovascular physiology is essential to understand the pathogenesis of neonatal brain damage and can help pediatricians in an accurate interpretation of the flow profile in neurological pathology.