Measuring cardiac output in one-lung ventilation: a comparison of pulmonary artery and transpulmonary aortic measurements in pigs.
OBJECTIVE
The agreement between cardiac output measurements via pulmonary artery thermodilution (CO[PA]) and transpulmonary aortic thermodilution (CO[AT]) during one-lung ventilation was studied.


METHODS
Animal study with repeated simultaneous measurements comparing 2 cardiac output measurement techniques.


METHODS
Experimental animal facility of a university department.


METHODS
Forty-eight female pigs (26-42 kg).


METHODS
The pigs were anesthetized, tracheally intubated, and mechanically ventilated. After placement of an aortic thermistor catheter via the femoral artery and a pulmonary artery catheter, a double-lumen tube was placed via tracheotomy. During one-lung ventilation in each animal, 3 measurements with pulmonary artery thermodilution and transpulmonary aortic thermodilution were performed in different hemodynamic states. Both thermistors were connected to 1 computer system, and 144 simultaneous cardiac output measurements were analyzed.


RESULTS
Linear regression analyses revealed a close relationship between the 2 methods: CO(AT) = 0.81 CO(PA) + 1.04 (L/min) (r = 0.96, p < 0.0001). Bland-Altman analysis showed that CO(AT) was slightly higher than the CO(PA) with a bias of 0.2 +/- 0.5 L/min. However, in higher CO states, an inversion of this relationship was found, possibly because of indicator loss and recirculation.


CONCLUSIONS
The pulmonary artery thermodilution and the transpulmonary aortic thermodilution techniques both accurately measure cardiac output during one-lung ventilation.
Hüter
Lars
L
Department of Anaesthesiology and Intensive Care Medicine, University of Jena, Jena, Germany.
Schwarzkopf
Konrad
K
Preussler
Niels-Peter
NP
Gaser
Elke
E
Schubert
Harald
H
Karzai
Waheedullah
W
Schreiber
Torsten
T
D000818:Animals; D001011:Aorta / Q000502:physiology*; D002302:Cardiac Output / Q000502:physiology*; D002407:Catheterization, Swan-Ganz / Q000379:methods; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D016014:Linear Models; D011651:Pulmonary Artery / Q000502:physiology*; D012121:Respiration, Artificial / Q000379:methods*; D013552:Swine; D013815:Thermodilution / Q000379:methods; D013997:Time Factors