title: Non-invasive measurement of cardiac output: whole-body impedance cardiography in simultaneous comparison with thermodilution and direct oxygen Fick methods.
abstract: OBJECTIVE
  To determine the reliability of whole-body impedance cardiography (ICGWB), with electrodes attached to wrists and ankles, in the measurement of cardiac output (CO) on the basis of simultaneous comparison with thermodilution (TD) and direct oxygen Fick (Fick) methods.
  
  
  METHODS
  Prospective clinical study.
  
  
  METHODS
  A surgical intensive care unit at a university hospital.
  
  
  METHODS
  Thirty consecutive subjects undergoing a coronary artery bypass surgery were investigated preoperatively.
  
  
  METHODS
  ICGWB derived CO was measured simultaneously with the TD and Fick methods to establish the biases and limits of agreement (LA) between the methods.
  
  
  RESULTS
  The results obtained by ICGWB and the invasive methods showed good agreement. The bias and LA between COTD and COICG were 0.00 l/min: 1.37 and 1.37 l/min, respectively, and were close to those obtained between COTD and COFICK, 0.32 l/min; 1.74 and -1.10 l/min. The bias and LA between the COFICK and COICG were -0.32 l/min; -2.24 and 1.60 l/min respectively. The repeatability value of consecutive single measurements for ICGWB (RVICG = 0.57 l/min) was much better than for the TD method (RVTD = 1.10 l/min).
  
  
  CONCLUSIONS
  There was close agreement between the results of the three methods in the measurement of CO. In sedated preoperative patients the accuracy of ICGWB is within clinically acceptable limits and its repeatability is excellent. ICGWB provides a useful alternative to the TD and Fick methods in cases where the pressures supplied by the pulmonary artery catheter are not essential.
authors.affiliation: Department of Clinical Physiology, Tampere University Hospital, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Kööbi
authors.forename: S
authors.initials: S
authors.lastname: Kaukinen
authors.forename: T
authors.initials: T
authors.lastname: Ahola
authors.forename: V M
authors.initials: VM
authors.lastname: Turjanmaa
mesh_terms: D000328:Adult; D000368:Aged; D001944:Breath Tests; D002302:Cardiac Output; D002307:Cardiography, Impedance / Q000379:methods*; D001026:Coronary Artery Bypass; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000032:analysis* / Q000097:blood; D011300:Preoperative Care; D011446:Prospective Studies; D015203:Reproducibility of Results; D013815:Thermodilution / Q000379:methods*
chemical_list: D010100:Oxygen