Simultaneous Measurements of Cardiac Output by Thoracic Electric Bioimpedance , Transesophageal Doppler , and Thermodilution in Anesthetized Patients

Noh, Gyu Jeong; Kim, Chong Sung; Kim, Kwang Woo

Abstract

Simultaneous intraoperative measurements of eardiac output were obtained in twenty one patients with thoracic electric bioimpedance(TEB) and transesophageal Doppler, two patients with transesophageal Doppler and thermodilution, one patient with TEB and thermodilution, and three patients with TEB, transesophageal Doppler and thermodilution techniques to evaluate the utility of noninvasive methods. Pairs of measurments were obtained 6S times with TEB and thermodilution, 109 times with transesophageal Doppler and thermodilution, and 373 times with TEB and transesophageal Doppler techniques. Correlation of the measurements was poor, with r=0.39 for TEB and thermodilution, r=0.44 for transesophageal Doppler and thermodilution, and r=0.39 for TEB and transesophageal Doppler. The mean difference between TEB and thermodilution, transesophageal Doppler and thermodilution, and TEB and transesophageal Doppler values was -2.41+/-1.79 L/min(mean+/-SD), -0.98+/-1.70 L/min, and -0.69+/-1.01 L/min, respectively. The scattergrams with confidence band lines showed that 22.0% of the scattergram points fell within +/-20% band and 51.5% within +/-40% band in TEB and thermodilution, 55.0% of the scattergram points fell within +/-20% band and 77.9% within +/-40% band in transesophageal Doppler and thermodilution, and 63.6% of the scattergram points fell within +/-20% band and 90.9 within +/-40% band in TEB and transesophageal Doppler. Therefore, it is concluded that neither noninvasive technique reliably estimated cardiac output as determined by thermodilution.