title: Femoral venous oxygen saturation is no surrogate for central venous oxygen saturation.
abstract: OBJECTIVE
  The purpose of our study was to determine if central venous oxygen saturation and femoral venous oxygen saturation can be used interchangeably during surgery and in critically ill patients.
  
  
  METHODS
  Prospective observational controlled study.
  
  
  METHODS
  Nonacademic university-affiliated teaching hospital in The Netherlands.
  
  
  METHODS
  One hundred cardiac outpatients, 30 high-risk surgical patients, and 30 critically ill patients.
  
  
  METHODS
  None.
  
  
  RESULTS
  We concurrently determined femoral venous oxygen saturation and central venous oxygen saturation in a group of 100 stable cardiac patients, which served as control group. Furthermore, we determined simultaneously femoral venous oxygen saturation and central venous oxygen saturation in 30 surgical patients and in 30 critically ill patients and evaluated changes over time. Correlation and agreement of femoral venous oxygen saturation and central venous oxygen saturation were assessed, including the difference between femoral venous oxygen saturation and central venous oxygen saturation.Despite significant correlation between obtained values of femoral venous oxygen saturation and central venous oxygen saturation (rs = 0.55; p < .001), the limits of agreement were wide in the control group (mean bias 2.7% ± 7.9%; 95% limits of agreement -12.9% to 18.2%). In both the surgical and critically ill patients, limits of agreement (mean bias of -1.9% ± 9.3%; 95% limits of agreement -20.0% to 16.3%, and mean bias of 4.6% ± 14.3%; 95% limits of agreement -23.5% to 32.6%, respectively) were wide. Results for changes of femoral venous oxygen saturation and central venous oxygen saturation were similar. During initial treatment of critically ill patients, the difference between femoral venous oxygen saturation and central venous oxygen saturation including its range of variation diminished.
  
  
  CONCLUSIONS
  There is lack of agreement between femoral venous oxygen saturation and central venous oxygen saturation in both stable and unstable medical conditions. Thus, femoral venous oxygen saturation should not be used as surrogate for central venous oxygen saturation.
authors.affiliation: Department of Anesthesiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. p.van. beest@umcg.nl
authors.forename: Paul A
authors.initials: PA
authors.lastname: van Beest
authors.forename: Alice
authors.initials: A
authors.lastname: van der Schors
authors.forename: Henriëtte
authors.initials: H
authors.lastname: Liefers
authors.forename: Ludo G J
authors.initials: LG
authors.lastname: Coenen
authors.forename: Richard L
authors.initials: RL
authors.lastname: Braam
authors.forename: Najib
authors.initials: N
authors.lastname: Habib
authors.forename: Annemarije
authors.initials: A
authors.lastname: Braber
authors.forename: Thomas W L
authors.initials: TW
authors.lastname: Scheeren
authors.forename: Michaël A
authors.initials: MA
authors.lastname: Kuiper
authors.forename: Peter E
authors.initials: PE
authors.lastname: Spronk
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002405:Catheterization, Central Venous; D002496:Central Venous Pressure / Q000502:physiology; D016638:Critical Illness; D005260:Female; D005268:Femoral Vein; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology*; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000502:physiology; D036301:Qualitative Research; D014682:Vena Cava, Inferior / Q000502:physiology; D014683:Vena Cava, Superior / Q000502:physiology
chemical_list: D010100:Oxygen