title: Cardiac output determinations in the newborn. Reproducibility of the pulsed Doppler velocity measurement.
abstract: 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.
authors.affiliation: Department of Pediatrics, University of Kansas Medical Center, Kansas City 66103.
authors.forename: K S
authors.initials: KS
authors.lastname: Claflin
authors.forename: D C
authors.initials: DC
authors.lastname: Alverson
authors.forename: D
authors.initials: D
authors.lastname: Pathak
authors.forename: P
authors.initials: P
authors.lastname: Angelus
authors.forename: C
authors.initials: C
authors.lastname: Backstrom
authors.forename: S
authors.initials: S
authors.lastname: Werner
mesh_terms: D001011:Aorta / Q000033:anatomy & histology / Q000502:physiology; D001783:Blood Flow Velocity; D002302:Cardiac Output; D004452:Echocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D012212:Rheology; D013318:Stroke Volume