Variability in cerebral blood flow velocity: observations over one minute in preterm babies.
Cerebral blood flow velocity (CBFV) was measured using Doppler ultrasound on the first day of life in a consecutively admitted cohort of 52 very low birthweight infants. Recordings were made for a period of 1 min. The coefficient of variation for the area under the curve of 20 successive cardiac cycles was calculated, and a 20 cycle moving window then applied to the whole recording. This showed that the coefficient of variation varied widely during 1 min in any individual, the range being from 2% to 28% (median 8%). There was a strong correlation between the variability in CBFV and that in systemic blood pressure (BP). Variability in CBFV was significantly higher in babies with hypotensive episodes (P = 0.026). Babies who died had a higher maximum coefficient of variation than those who survived (P = 0.05), but we were unable to confirm any association with brain injury or patent ductus arteriosus.
Coughtrey
H
H
N.I.C.U., Rosie Maternity Hospital, Cambridge, UK.
Rennie
J M
JM
Evans
D H
DH
D001724:Birth Weight; D001783:Blood Flow Velocity; D001794:Blood Pressure; D002560:Cerebrovascular Circulation; D004374:Ductus Arteriosus, Patent / Q000000981:diagnostic imaging; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D011446:Prospective Studies; D018608:Ultrasonography, Doppler