Related Experiment Video
Updated: Oct 20, 2025
Hemodynamic Precision in the Neonatal Intensive Care Unit using Targeted Neonatal Echocardiography
Published on: January 27, 2023
Bioreactance Cardiac Output Trending Ability in Preterm Infants: A Single Centre, Longitudinal Study
Lizelle Van Wyk1, Johan Smith1, John Lawrenson2
1Division Neonatology, Department of Paediatrics and Child Health, Stellenbosch University and Tygerberg Children's Hospital, Cape Town, South Africa.
Introduction:
It is unknown whether bioreactance (BR) can accurately track cardiac output (CO) changes in preterm neonates.
Methods:
A prospective observational longitudinal study was performed in stable preterm infants (<37 weeks) during the first 72 h of life. Stroke volume (SV) and CO, as measured by BR and transthoracic echocardiography, were compared.
Results:
The mean gestational age (GA) was 31.3 weeks and mean birth weight (BW) was 1,563 g. Overall, 690 measurements were analysed for trending ability by 4-quadrant and polar plots. For non-weight-indexed measurements, 377 (54.6%) lay outside the 5% exclusion zone, the concordance rate was poor (77.2%) with a high mean angular bias (28.6°), wide limits of agreement and a poor angular concordance rate (17.4%). Neither GA, BW nor respiratory support mode affected trending data. Patent ductus arteriosus, postnatal age, and CO level had variable effects on trending data. Trending data for 5 and 10% exclusion zones were also compared.
Conclusion:
The ability of BR to track changes in CO is not interchangeable with CO changes as measured by echocardiography. BR, as a trend monitor for changes in CO or SV to determine clinical decisions around interventions in neonatology, should be used with caution.
