Validity of cardiac output measurement by computer-averaged impedance cardiography, and comparison with simultaneous thermodilution determinations.
The accuracy and reproducibility of noninvasive cardiac output determinations by computer-averaged impedance cardiography were compared with those of simultaneously performed thermodilution cardiac output. In all, 43 patients (14 men and 29 women = 201 pairs) were studied by simultaneously performed impedance and thermal determinations. Individual impedance values correlated with paired thermodilution determinations (r = 0.75; p less than 0.0001). Each patient's average thermodilution values correlated with the average impedance values (r = 0.86; p less than 0.0001). Mean thermodilution output was 4.6 +/- 1.37 liters/min. Mean impedance output was 4.5 +/- 1.27 liter/min Reproducibility was comparable for impedance (0.0059 +/- 0.639) and thermodilution cardiac output (0.023 +/- 0.556). There was high agreement between methods by plot of the difference against mean of the 2 methods. Impedance cardiac output values agree and correlate highly with quality-controlled thermodilution outputs across a wide range of clinical conditions and hemodynamic values.
Pickett
B R
BR
Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock 79430.
Buell
J C
JC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002302:Cardiac Output / Q000502:physiology*; D002307:Cardiography, Impedance / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D013815:Thermodilution