THORACIC ELECTRICAL BIOIMPEDANCE - A NONINVASIVE MEASURE OF CARDIAC-OUTPUT FOR PORCINE RESEARCH

A comparison of two techniques for measuring cardiac output, thermodil ution (TD) and thoracic electrical bioimpedance (TEB), was undertaken in a porcine model. Eight anaesthetized large white pigs were studied. A total of 436 paired measurements were performed over a range of car diac outputs from 1.7 to 15.1l/min as measured by thermodilution. The Pearson product moment correlation coefficient was r=0.963 with P < 0. 001. Analysis by Bland and Altman statistics revealed a mean differenc e (bias) of -0.02l/min and the limits of agreement were +/- 1.6l/min, similar to figures found in human comparative studies. These results c onfirm that thoracic electrical bioimpedance is a valid method of meas uring cardiac output in pigs. It has significant advantages compared t o thermodilution, in particular it is cheap, simple to use, non-invasi ve and provides continuous data.