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Updated: Apr 11, 2026
Author Spotlight: Assessment of Cardiac Output Calculation by Thermodilution in Pigs for Effective Perfusion Flow During EVLP
Published on: June 28, 2024
A novel continuous capnodynamic method for cardiac output assessment in a porcine model of lung lavage
C Hällsjö Sander1,2, M Hallbäck3, F Suarez Sipmann4,5
1Department of Anaesthesiology, Surgical Services and Intensive Care Medicine, Karolinska University Hospital, Solna, Sweden.
Background:
We have evaluated a new method for continuous monitoring of effective pulmonary blood flow (COEPBF ), i.e. cardiac output (CO) minus intra-pulmonary shunt, during mechanical ventilation. The method has shown good trending ability during severe hemodynamic challenges in a porcine model with intact lungs. In this study, we further evaluate the COEPBF method in a model of lung lavage.
Methods:
COEPBF was compared to a reference method for CO during hemodynamic and PEEP alterations, 5 and 12 cmH2 O, before and after repeated lung lavages in 10 anaesthetised pigs. Bland-Altman, four-quadrant and polar plot methodologies were used to determine agreement and trending ability.
Results:
After lung lavage at PEEP 5 cmH2 O, the ratio of arterial oxygen partial pressure related to inspired fraction of oxygen significantly decreased. The mean difference (limits of agreement) between methods changed from 0.2 (-1.1 to 1.5) to -0.9 (-3.6 to 1.9) l/min and percentage error increased from 34% to 70%. Trending ability remained good according to the four-quadrant plot (concordance rate 94%), whereas mean angular bias increased from 4° to -16° when using the polar plot methodology.
Conclusion:
Both agreement and precision of COEPBF were impaired in relation to CO when the shunt fraction was increased after lavage at PEEP 5 cmH2 O. However, trending ability remained good as assessed by the four-quadrant plot, whereas the mean polar angle, calculated by the polar plot, was wide.
