Journal of Ultrasound in Medicine, Vol 7, Issue 6 311-315, Copyright © 1988 by American Institute of Ultrasound in Medicine
Cardiac output determinations in the newborn. Reproducibility of the pulsed Doppler velocity measurement
K. S. Claflin, D. C. Alverson, D. Pathak, P. Angelus, C. Backstrom and S. Werner
Department of Pediatrics, University of Kansas Medical Center, Kansas City 66103.
Cardiac output (QAo) can be estimated noninvasively by pulsed Doppler (PD)
ultrasonographic determination of mean ascending aortic blood flow velocity
(VAo) combined with M-mode echocardiographic determination of ascending
aortic cross sectional area (AAo). Cardiac output is calculated from the
volumetric flow equation (QAo) = (VAo) X (AAo). Pulsed Doppler measurements
are known to correlate well with Fick and thermodilution methods; however,
inter- and intraoperator variability of the velocity component of the PD
method has not been determined in newborns. We did three repeated PD
measures of mean aortic flow velocity in ten term infants (using four
trained operators) to determine inter- and intraoperator reproducibility.
The coefficient of variation for intraoperator variability (random error)
for a single measurement of VAo was 11.7%. If three repeated measures by a
single operator were averaged, the random error was 7.0%. There was little
interoperator variability found.
