title: Arterial pressure-based cardiac output monitoring: a multicenter validation of the third-generation software in septic patients.
abstract: OBJECTIVE
  Second-generation FloTrac software has been shown to reliably measure cardiac output (CO) in cardiac surgical patients. However, concerns have been raised regarding its accuracy in vasoplegic states. The aim of the present multicenter study was to investigate the accuracy of the third-generation software in patients with sepsis, particularly when total systemic vascular resistance (TSVR) is low.
  
  
  METHODS
  Fifty-eight septic patients were included in this prospective observational study in four university-affiliated ICUs. Reference CO was measured by bolus pulmonary thermodilution (iCO) using 3-5 cold saline boluses. Simultaneously, CO was computed from the arterial pressure curve recorded on a computer using the second-generation (CO(G2)) and third-generation (CO(G3)) FloTrac software. CO was also measured by semi-continuous pulmonary thermodilution (CCO).
  
  
  RESULTS
  A total of 401 simultaneous measurements of iCO, CO(G2), CO(G3), and CCO were recorded. The mean (95%CI) biases between CO(G2) and iCO, CO(G3) and iCO, and CCO and iCO were -10 (-15 to -5)% [-0.8 (-1.1 to -0.4) L/min], 0 (-4 to 4)% [0 (-0.3 to 0.3) L/min], and 9 (6-13)% [0.7 (0.5-1.0) L/min], respectively. The percentage errors were 29 (20-37)% for CO(G2), 30 (24-37)% for CO(G3), and 28 (22-34)% for CCO. The difference between iCO and CO(G2) was significantly correlated with TSVR (r(2) = 0.37, p < 0.0001). A very weak (r(2) = 0.05) relationship was also observed for the difference between iCO and CO(G3).
  
  
  CONCLUSIONS
  In patients with sepsis, the third-generation FloTrac software is more accurate, as precise, and less influenced by TSVR than the second-generation software.
authors.affiliation: Department of Intensive Care, Erasme University Hospital, Université Libre de Bruxelles, Route de Lennik 808, 1070 Brussels, Belgium. ddebacke@ulb.ac.be
authors.forename: Daniel
authors.initials: D
authors.lastname: De Backer
authors.forename: Gernot
authors.initials: G
authors.lastname: Marx
authors.forename: Andrew
authors.initials: A
authors.lastname: Tan
authors.forename: Christopher
authors.initials: C
authors.lastname: Junker
authors.forename: Marc
authors.initials: M
authors.lastname: Van Nuffelen
authors.forename: Lars
authors.initials: L
authors.lastname: Hüter
authors.forename: Willy
authors.initials: W
authors.lastname: Ching
authors.forename: Frédéric
authors.initials: F
authors.lastname: Michard
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Vincent
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D002302:Cardiac Output / Q000502:physiology*; D002407:Catheterization, Swan-Ganz; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D018805:Sepsis / Q000503:physiopathology*; D012984:Software; D056987:Vasoplegia / Q000503:physiopathology