Abstract
Purpose: To compare the accuracy of cardiac output (CO) measurement by arterial pulse waveform analysis (COPW) to thermodilution assessments in patients with aortic stenosis, a high-risk patient group who may benefit from extended hemodynamic monitoring.
Methods: In 30 patients with aortic stenosis, CO was assessed in triplicate by thermodilution via pulmonary artery catheterization (COPAC), and by arterial pulse waveform analysis (COPW), before and after valve replacement. The techniques were compared by assessing the repeatability coefficient of each method and by calculating the percentage error, bias, and the limits of agreement between methods.
Results: The repeatability coefficients of COPAC and COPW were 0.89 L·min−1 and 1.04 L·min−1 respectively after induction of anesthesia, which corresponded to 24% of COPAC and 26% of COPW, and increased to 33% of COPAC and 32% of COPW immediately after extracorporeal circulation. A systematic error between methods was not observed. The limits of agreement were bias±1.42 L·min−1 after anesthesia induction, corresponding to a 36% percentage error. The scattering of differences between methods increased markedly after termination of extracorporeal circulation (percentage error 56%).
Conclusion: The repeatability of COPAC, as well as of COPW, is reduced in patients with aortic stenosis. The repeatability of both methods, as well as the agreement between methods, decreased markedly immediately after termination of cardiopulmonary bypass.
Résumé
Objectif: Comparer la précision de la mesure du débit cardiaque (CO) par analyse du contour de la pression artérielle (COPW) aux évaluations par thermodilution chez les patients présentant une sténose aortique, un groupe de patients à haut risque qui pourraient bénéficier d’un monitorage hémodynamique étendu.
Méthode: Le CO a été mesuré en triplicata par thermodilution, via un cathéter de l’artère pulmonaire (COPAC), et par analyse du contour de la pression artérielle (COPW), chez 30 patients souffrant de sténose aortique avant et après le remplacement valvulaire. Les techniques ont été comparées en évaluant le coefficient de reproductibilité de chaque méthode et en calculant le pourcentage d’erreur, le biais et les limites de la concordance des méthodes.
Résultats : Les coefficients de reproductibilité de COPAC ET COPW étaient de 0,89 L·min−1 et 1,04 L·min−1 respectivement après induction de l’anesthésie, ce qui correspond à 24 % de COPAC et 26 % de COPW, et ont augmenté à 33 % de COPAC et 32 % de COPW immédiatement après la circulation extracorporelle. Aucune erreur systématique entre les méthodes n’a été observée. Les limites de la concordance étaient un biais de±1,42 L·min−1 après l’induction de l’anesthésie, soit un pourcentage d’erreur de 36 %. La distribution des différences entre les méthodes a considérablement augmenté après la fin de la circulation extracorporelle (pourcentage d’erreur 56 %).
Conclusion : La reproductibilité de COPAC ainsi que de COPW est réduite chez les patients souffrant de sténose aortique. La reproductibilité des deux méthodes, ainsi que la concordance entre les méthodes, ont considérablement diminué après la fin de la circulation extracorporelle.
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This study was supported with funds from Edwards LifeSciences, Irvine, CA, USA.
Competing interests: None.
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Staier, K., Wiesenack, C., Günkel, L. et al. Cardiac output determination by thermodilution and arterial pulse waveform analysis in patients undergoing aortic valve replacement. Can J Anaesth 55, 22–28 (2008). https://doi.org/10.1007/BF03017593
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DOI: https://doi.org/10.1007/BF03017593