[Introduction and clinical evaluation of a new non-invasive cardiac output monitor (NICO) based on Fick partial CO2 rebreathing method].

A newly developed non-invasive monitor, NICO (Novametrix Medical Systems Inc.), measures cardiac output based on changes in respiratory CO2 concentration caused by a brief period of rebreathing. By applying modified form of the CO2 Fick principle, cardiac output is calculated. We determined the accuracy and precision of this technique (RBCO) by comparing it with continuous thermodilution technique (TDCCO) and pulse dye densitometry technique (PDD). The overall difference between RBCO and TDCCO(n = 46) was -0.21 +/- 1.43 (bias +/- 2 SD)l.min-1. On the other hand, the overall difference between RBCO and PDD (n = 53) was -0.1 +/- 2.04 (bias +/- 2 SD)l.min-1. The degree of accuracy of RBCO was thought to be the same as those of TDCCO and PDD. We expect that NICO will be a useful cardiac output monitor in any method of general anesthesia in which PA catheterization is difficult or not indicated.