ESTIMATION OF THE PERIPHERAL VASCULAR-RES ISTANCE IN THE AORTA OF THEFETAL SHEEP USING EXTERNAL DOPPLERSONOGRAPHIE

Objectives: Do external Doppler indices correlated sufficiently to the peripheral resistance? Methods: The resistance of 7 fetal sheep was m easured inductively and was correlated to external Doppler measurement s. The correlation of different indices and methods was compared. Resu lts: Only bloodflow velocities and the harmonic component index (HCl) yield good correlations (r greater than or equal to 7) to the peripher al resistance, PI, RI, SID-Ratio and Vpeak/Vmean showed r-values from .47 to .59. None of the Doppler parameters reached the values of indic es derived from the inductive flowprobe. Conclusions: The blood flow v elocities and the HCl seem to be superior to the classical indices in estimation of blood flow in the fetal aorta.