AUTOREGULATION OF CEREBRAL BLOOD FLOW (CBF) ESTIMATED BY TRANSFONTANEL DOPPLERVELOCIMETRY (TFDV) OF INTERNAL CAROTID ARTERY (ICA):

Lack of autoregulation of CBF has been shown in preterm neonates. It is an open question, wether this is related to low gestational age (GA) or to low absolute level of mean arterial blood pressure (MAP). We used mean blood flow velocity derived from the outline of the Doppler spectral curve (Vmax) of ICA by TFDV to estimate changes of CBF while MAP (oscillometry) changed due to infusion of plasma or katecholamines. TFDV was performed in 7 hypotensive and 4 normotensive infants < 31 wk, and in 6 hypotensive infants > 30 wk.ΔVma/ΔMAP was calculated as a measure of autoregulatory dysfunction.