title: Validation of transpulmonary thermodilution cardiac output measurement in a pediatric animal model.
abstract: OBJECTIVE
  This study was undertaken to validate the transpulmonary thermodilution cardiac output measurement (CO(TPTD)) in a controlled newborn animal model under various hemodynamic conditions with special emphasis on low cardiac output.
  
  
  METHODS
  Prospective, experimental, pediatric animal study.
  
  
  METHODS
  Animal laboratory of a university hospital.
  
  
  METHODS
  Twelve lambs.
  
  
  METHODS
  We studied 12 lambs under various hemodynamic conditions. Cardiac output was measured using the transpulmonary thermodilution technique with central venous injections of ice-cold saline. An ultrasound transit time perivascular flow probe around the main pulmonary artery served as the standard reference measurement (CO(UFP)). During the experiment, animals were resuscitated from hemodynamic shock using fluid boluses. Cardiac output measurements were performed throughout the experiment.
  
  
  RESULTS
  The correlation coefficient between CO(TPTD) and CO(UFP)was .97 (95% confidence interval .94-.98, p < .0001). Bland-Altman analysis showed a mean bias of 0.19 L/min with limits of agreement of -0.04 and 0.43 L/min (12.0% and +/-14.7%, respectively). The correlation coefficient between changes in CO(TPTD) and CO(UFP) during volume loading was .95 (95% confidence interval .91-.96, p < .0001). There was a significant correlation between changes in global end-diastolic volume and changes in stroke volume (r = .59) but not between changes in central venous pressure and changes in stroke volume (r = .03).
  
  
  CONCLUSIONS
  The transpulmonary thermodilution technique is a reliable method of measuring cardiac output in newborn animals. It is also capable of tracking changes in cardiac output.
authors.affiliation: Department of Intensive Care Medicine, Radboud University, Nijmegen Medical Centre, Nijmegen, The Netherlands. j.lemson@ic.umcn.nl
authors.forename: Joris
authors.initials: J
authors.lastname: Lemson
authors.forename: Willem P
authors.initials: WP
authors.lastname: de Boode
authors.forename: Jeroen C W
authors.initials: JC
authors.lastname: Hopman
authors.forename: Sandeep K
authors.initials: SK
authors.lastname: Singh
authors.forename: Johannes G
authors.initials: JG
authors.lastname: van der Hoeven
mesh_terms: D000818:Animals; D002302:Cardiac Output; D008168:Lung / Q000098:blood supply*; D023421:Models, Animal; D012756:Sheep; D013815:Thermodilution / Q000379:methods