title: A prospective study of the accuracy and precision of continuous cardiac output monitoring devices as compared to intermittent thermodilution.
abstract: BACKGROUND
  Pulse pressure (PP) analysis from a radial arterial line is available with the LiDCO plus monitor (LiDCO, Cambridge, UK) and FloTrac/Vigileo (Edwards Lifesciences, Irvine, CA, USA). The aim of this study was to investigate the agreement of continuous PP analysis against intermittent thermodilution (ITD) using the pulmonary artery catheter (PAC).
  
  
  METHODS
  This was a six-hour study in 29 patients monitored with a PAC. All measurements were referenced against CO measured from the average of four ITD curves from the PAC. The LiDCO plus was calibrated with a lithium dilution (PulseCOLi) and with ITD (PulseCOITD) at baseline. Measurements from Vigileo software 1.03 (APCO), LiDCO plus (PulseCOLi and PulseCOITD), CCO and ITD were taken every hour for the next six hours. The bias and precision between the two devices were calculated as well as the percentage error (PE) of agreement between the tested device and the reference. The coefficient of variation (CV) of the tested device was then derived.
  
  
  RESULTS
  The average bias, PE and coefficient of variation for CCO vs. ITD of the tested device were 0.3 L/min, 28% and 13%, respectively; for APCO vs. ITD the calculations were -1.1 L/min, 55% and 27%; for PulseCOLi Cardiac output Blood pressure Thermodilution. ITD they were 0.5 L/min, 40% and 19%; and for PulseCOITD vs. ITD they were 0.2 L/min, -31% and 15%.
  
  
  CONCLUSIONS
  APCO (Vigileo software 1.03) and PulseCOLi showed a moderate agreement with the PAC. When PulseCO was calibrated with ITD (PulseCOITD) it showed excellent agreement, demonstrating that PulseCO performs well against ITD when the calibration process is optimally performed.
authors.affiliation: Department of General Intensive Care, St James Wing, St George's Hospital, Tooting, London, UK. maurizio.cecconi@stgeorges.nhs.uk
authors.forename: M
authors.initials: M
authors.lastname: Cecconi
authors.forename: D
authors.initials: D
authors.lastname: Dawson
authors.forename: R
authors.initials: R
authors.lastname: Casaretti
authors.forename: R M
authors.initials: RM
authors.lastname: Grounds
authors.forename: A
authors.initials: A
authors.lastname: Rhodes
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002138:Calibration; D002302:Cardiac Output / Q000502:physiology*; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008094:Lithium; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012984:Software; D013815:Thermodilution / Q000295:instrumentation / Q000379:methods*
chemical_list: D008094:Lithium