Comparison of Measurements of Cardiac Output by Electrical Impedance and Thermodilution in Coronary Artery Bypass Graft Patients. |
Hae Kyoung Kim, Hyung Hee Park, Byung Moon Ham |
1Department of Anesthesiology, College of Medicine, InHa University, InHa General Hospital, Sungnam, Korea. 2Department of Anesthesiology, National Police Hospital, Seoul, Korea. 3Department of Anesthesiology, Seoul Naional University, College of Medicine, Seoul, Korea. |
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Abstract |
Simultaneous perioperative measurements of cradiac output were obtained in 16 patients for coronary artery bypass graft with transthoracic impedance and pulmonary artery thermodilution techniques to evaluate the utility of the noninvasive methods. Correlation coefficient of average pairs of the two methods was 0.81 (heart rate<60) 1.00 (60< or =heart rate<70) 0.82 (70< or =heart rate<80) 0.52 (80< or =heart rate<90) 0.65 (heart rate> or =90). Correlation coefficient of individual pairs of the two methods was 0.73 (heart rate<60) 0.99 (60< or =heart rate<70) 0.72 (70< or =heart rate<80) 0.60 (80< or =heart rate<90) 0.57 (heart rate> or =90). Each value has a significance with 95% confidence except average pairs below 60 of heart rate. In a scattergram with +/-20% confidence bands, 100% of data points fall inside this confidence bands when the heart rate is below 70. Each value has a significance with 95% confidence except average pairs below 60 of heart rate. In a scattergram with +/-20% confidence bands, 100% of data points fall inside this confidence bands when the heart rate is below 70, Two methods are in good agreement when the heart rate is below 70. It is concluded that transthoracic impedance can replace thermodilution method for coronary artery bypass graft, at least, in operating room and intensive care unit because heart rate should be managed at relatively low range. |
Key Words:
cardiac output; impedance; thermodilution |
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