AUTHOR=Quintana-Villamandos Begoña , Barranco Mónica , Fernández Ignacio , Ruiz Manuel , del Cañizo Juan Francisco 

TITLE=New Advances in Monitoring Cardiac Output in Circulatory Mechanical Assistance Devices. A Validation Study in a Porcine Model

JOURNAL=Frontiers in Physiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2021.634779

DOI=10.3389/fphys.2021.634779

ISSN=1664-042X

ABSTRACT=<p>Cardiac output (CO) measurement by continuous pulmonary artery thermodilution (CO<sub><italic>CTD</italic></sub>) has been studied in patients with pulsatile-flow LVADs (left ventricular assist devices), confirming the clinical utility. However, it has not been validated in patients with continuous-flow LVADs. Therefore, the aim of this study was to assess the validity of CO<sub><italic>CTD</italic></sub> in continuous-flow LVADs. Continuous-flow LVADs were implanted in six miniature pigs for partial assistance of the left ventricle. Both methods of measuring CO—measurement by CO<sub><italic>CTD</italic></sub> and intermittent pulmonary artery thermodilution, standard technique (CO<sub><italic>ITD</italic></sub>)—were used in four consecutive moments of the study: before starting the LVAD (basal moment), and with the LVAD started in normovolemia, hypervolemia (fluid overloading), and hypovolemia (shock hemorrhage). At the basal moment, CO<sub><italic>CTD</italic></sub> and CO<sub><italic>ITD</italic></sub> were closely correlated (<italic>r</italic><sup>2</sup> = 0.97), with a mean bias of −0.13 ± 0.16 L/min and percentage error of 11%. After 15 min of partial support LVAD, CO<sub><italic>CTD</italic></sub> and CO<sub><italic>ITD</italic></sub> were closely correlated (<italic>r</italic><sup>2</sup> = 0.91), with a mean bias of 0.31 ± 0.35 L/min and percentage error of 20%. After inducing hypervolemia, CO<sub><italic>CTD</italic></sub> and CO<sub><italic>ITD</italic></sub> were closely correlated (<italic>r</italic><sup>2</sup> = 0.99), with a mean bias of 0.04 ± 0.07 L/min and percentage error of 5%. After inducing hypovolemia, CO<sub><italic>CTD</italic></sub> and CO<sub><italic>ITD</italic></sub> were closely correlated (<italic>r</italic><sup>2</sup> = 0.74), with a mean bias of 0.08 ± 0.22 L/min and percentage error of 19%. This study shows that continuous pulmonary thermodilution could be an alternative method of monitoring CO in a porcine model with a continuous-flow LVAD.</p>