title: Third-generation FloTrac/Vigileo does not reliably track changes in cardiac output induced by norepinephrine in critically ill patients.
abstract: BACKGROUND
  The ability of the third-generation FloTrac/Vigileo software to track changes in cardiac index (CI) induced by volume expansion and norepinephrine in critically ill patients is unknown.
  
  
  METHODS
  In subjects with circulatory failure, we administered volume expansion (20 subjects) and increased (20 subjects) or decreased (20 subjects) the dose of norepinephrine. We measured arterial pressure waveform-derived CI provided by the third-generation FloTrac/Vigileo device (CI(pw)) and transpulmonary thermodilution CI (CI(td)) before and after therapeutic interventions.
  
  
  RESULTS
  Considering the pairs of measurements performed before and after all therapeutic interventions (n=60), a bias between the absolute values of CI(pw) and CI(td) was 0.26 (0.94) litre min(-1) m(-2) and the percentage error was 54%. Changes in CI(pw) tracked changes in CI(td) induced by volume expansion with moderate accuracy [n=20, bias=-0.11 (0.54) litre min(-1) m(-2), r(2)=0.26, P=0.02]. When changes in CI(td) were induced by norepinephrine (n=40), a bias between CI(pw) and CI(td) was 0.01 (0.41) litre min(-1) m(-2) (r(2)=0.11, P=0.04). The concordance rates between changes in CI(pw) and CI(td) induced by volume expansion and norepinephrine were 73% and 60%, respectively. The bias between changes in CI(pw) and CI(td) significantly correlated with changes in total systemic vascular resistance (r(2)=0.41, P<0.0001).
  
  
  CONCLUSIONS
  The third-generation FloTrac/Vigileo device was moderately reliable for tracking changes in CI induced by volume expansion and poorly reliable for tracking changes in CI induced by norepinephrine.
authors.affiliation: Hôpitaux universitaires Paris-Sud, Hôpital de Bicêtre, service de réanimation médicale, 78, rue du Général Leclerc, Le Kremlin-Bicêtre F-94270, France. xavier.monnet@bct.aphp.fr
authors.forename: X
authors.initials: X
authors.lastname: Monnet
authors.forename: N
authors.initials: N
authors.lastname: Anguel
authors.forename: M
authors.initials: M
authors.lastname: Jozwiak
authors.forename: C
authors.initials: C
authors.lastname: Richard
authors.forename: J-L
authors.initials: JL
authors.lastname: Teboul
mesh_terms: D001794:Blood Pressure; D002302:Cardiac Output / Q000187:drug effects*; D016638:Critical Illness; D004867:Equipment Design; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation*; D009638:Norepinephrine / Q000494:pharmacology*; D015203:Reproducibility of Results; D012984:Software; D013815:Thermodilution; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
chemical_list: D014662:Vasoconstrictor Agents; D009638:Norepinephrine