Experimental study of determination of cardiac output by dye method

Abstract

SummaryThe dye injection method and the direct Fick method for measuring the cardiac output have been compared in dogs under anesthesia. The fair agreement between the two methods in basic conditions was confirmed. The correlation between the two methods when the cardiac output was changed and maintained at a new and steady level in the same animal also proved to be good. However, comparison between the Fick method and the dye injection procedure is only possible in a steady state which is necessary for valid application of the Fick principle. Hence in acute hypoxia widely differing results were obtained by the two methods, the dye injection method showing higher values for the cardiac output. When in a relatively short time interval the determination of the cardiac output by the dye injection method was repeated, comparable data for the same animal were obtained.