VALIDATION OF THORACIC ELECTRICAL BIOIMPEDANCE AS A PORCINE RESEARCH TOOL

We have compared the accuracy of two methods of measuring cardiac outp ut, thoracic electrical bioimpedance (TEB) and thermodilution (TD), in pigs. We studied four anaesthetized pigs, producing 145 paired cardia c output values over a range of TD cardiac outputs of 2.6-12.6 litre m in(-1). TEB cardiac output was less than that measured by TD, by a con stant factor throughout the observed range of values, because of diffe rences in porcine thoracic shape. The Pearson product moment correlati on coefficient suggested a good correlation (r=0.984, P<0.001). More i mportantly, analysis by the Bland and Altman statistical method sugges ted a high level of agreement, with 95% confidence intervals of +/-1.0 litre min(-1). These results suggest that TEB can be used as a satisf actory method to measure cardiac output in porcine models.