title: Thermodilution and esophageal Doppler ultrasound in the assessment of blood flow changes induced by endotoxin and dobutamine.
abstract: BACKGROUND
  Intermittent (IT) and continuous (CT) thermodilution and esophageal Doppler (ED), are all used for hemodynamic monitoring. The aim of this study was to test the agreement between these methods during endotoxin (ET) and dobutamine infusion.
  
  
  METHODS
  Twenty-two pigs (39 +/- 1.8 kg body weight) were randomized to general anesthesia and either continuous ET (n = 9) or placebo (PL, n = 13) infusion. After 18 hours of ET or PL infusion, the animals were further randomized to receive dobutamine (n = 3 in ET, n = 5 in PL) or PL. A set of measurements using the three methods were obtained every hour, and the relative blood flow changes between two subsequent measurements were calculated.
  
  
  RESULTS
  Bias or limits of agreement for flows were 0.73 L/min or 1.80 L/min for IT and CT, -0.33 L/min or 4.29 L/min for IT and ED, and -1.06 or 3.94 for CT and ED (n = 515, each). For flow changes they were 1% or 44%, 2% or 59%, and 3% or 45%, respectively. Bias and limits of agreement did not differ in ET- and PL-treated animals or in animals with or without dobutamine. Despite significant correlation between any two methods, the respective correlation coefficients (r) were small (IT vs. CT: 0.452; IT vs. ED: 0.042; CT vs. ED: 0.069; all p < 0.001). The same directional changes were measured by any two methods in 49%, 40%, and 50%. When IT flows >5 L/min were compared with IT flows </=5 L/min, the latter had 49% (p < 0.001), 23% (p < 0.001), and 24% smaller limits of agreement than the former (p = 0.012).
  
  
  CONCLUSIONS
  IT and CT cardiac output agree only to a moderate level, and agreement between the respective relative blood flow changes is even worse. ED has poor agreement with both thermodilution methods, especially when cardiac output is >5 L/min.
authors.affiliation: Departments of Anesthesiology, Bern University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Taniguchi
authors.forename: Hendrik
authors.initials: H
authors.lastname: Bracht
authors.forename: Francesca
authors.initials: F
authors.lastname: Porta
authors.forename: Vladimir
authors.initials: V
authors.lastname: Krejci
authors.forename: Sayed Z
authors.initials: SZ
authors.lastname: Ali
authors.forename: Mario
authors.initials: M
authors.lastname: Beck
authors.forename: Daniel
authors.initials: D
authors.lastname: Mettler
authors.forename: Jukka
authors.initials: J
authors.lastname: Takala
authors.forename: Stephan M
authors.initials: SM
authors.lastname: Jakob
mesh_terms: D000818:Animals; D002302:Cardiac Output / Q000187:drug effects / Q000502:physiology*; D002316:Cardiotonic Agents / Q000494:pharmacology; D004280:Dobutamine / Q000494:pharmacology; D004731:Endotoxins / Q000494:pharmacology; D004926:Escherichia coli; D008070:Lipopolysaccharides; D012079:Renal Circulation / Q000187:drug effects / Q000502:physiology*; D015203:Reproducibility of Results; D013152:Splanchnic Circulation / Q000187:drug effects / Q000502:physiology*; D013552:Swine; D013815:Thermodilution; D018608:Ultrasonography, Doppler
chemical_list: D002316:Cardiotonic Agents; D004731:Endotoxins; D008070:Lipopolysaccharides; D004280:Dobutamine