title: Measuring cardiac output in one-lung ventilation: a comparison of pulmonary artery and transpulmonary aortic measurements in pigs.
abstract: 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.
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University of Jena, Jena, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Hüter
authors.forename: Konrad
authors.initials: K
authors.lastname: Schwarzkopf
authors.forename: Niels-Peter
authors.initials: NP
authors.lastname: Preussler
authors.forename: Elke
authors.initials: E
authors.lastname: Gaser
authors.forename: Harald
authors.initials: H
authors.lastname: Schubert
authors.forename: Waheedullah
authors.initials: W
authors.lastname: Karzai
authors.forename: Torsten
authors.initials: T
authors.lastname: Schreiber
mesh_terms: 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