title: Cardiac index based on measurements obtained in a bedside chair and in bed.
abstract: BACKGROUND
  Accurate measurements for determining cardiac index can be obtained while patients are supine in bed at various backrest elevations. It is not clear if these measurements are accurate when patients are in a bedside chair.
  
  
  OBJECTIVE
  To determine if cardiac index based on measurements obtained with the patient in a chair is similar to cardiac index based on measurements obtained with the patient in bed.
  
  
  METHODS
  A convenience sample of cardiac surgical patients and a method-comparison design were used to compare cardiac index values based on measurements obtained with patients in 2 different positions: in a chair and in the bed. A standard thermodilution technique was used to measure cardiac output. Measurement of cardiac output in the second position was obtained immediately after measurement in the first position. Positions were randomly assigned. Bias and precision were calculated and graphed with the Bland-Altman method. Differences in cardiac index of 0.50 or more were considered clinically significant. Analysis of variance was used to determine differences between cardiac index values for the 2 positions.
  
  
  RESULTS
  A total of 27 postoperative cardiac surgical patients were studied. Cardiac index values based on measurements obtained with patients in the 2 different positions did not differ significantly (F(1,50) = 0.446; P = .51). The mean difference score (bias) between the 2 positions was -0.07 (precision, 0.30).
  
  
  CONCLUSIONS
  The practice of putting cardiac surgical patients whose hemodynamic status is stable back to bed before obtaining measurements for calculation of cardiac index may not be required for accurate values.
authors.affiliation: Saint Luke's Hospital of Kansas City, Missouri 64111, USA.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Rader
authors.forename: Melissa
authors.initials: M
authors.lastname: Nelson
authors.forename: Cindy
authors.initials: C
authors.lastname: Sobek
authors.forename: Michelle
authors.initials: M
authors.lastname: Smith
authors.forename: Rose
authors.initials: R
authors.lastname: Garcia
authors.forename: Susan
authors.initials: S
authors.lastname: Wright
authors.forename: Kelly
authors.initials: K
authors.lastname: Moutray
authors.forename: Sarah
authors.initials: S
authors.lastname: Shrum
authors.forename: Nancy M
authors.initials: NM
authors.lastname: Richards
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D002302:Cardiac Output; D006348:Cardiac Surgical Procedures; D003325:Coronary Care Units; D005260:Female; D006801:Humans; D008297:Male; D008923:Missouri; D008991:Monitoring, Physiologic / Q000379:methods; D056888:Patient Positioning; D019095:Point-of-Care Systems; D011182:Postoperative Care / Q000379:methods; D013815:Thermodilution / Q000379:methods