The agreement between the NICO2 derived cardiac output and the de facto standard - thermodilution cardiac output - is poor. The methods are not interchangeable with the present version of the NICO2. The repeatability of the partial CO2-rebreathing technique holds promise that a sufficient accuracy may be obtained by suitable modifications of the monitor's algorithms.

The current study shows that one needs to average the results of four injections to be 95% confident that the result is within 5% of the 'true' cardiac output and that two series of four measurements have to differ by at least 7% before one can be sure (95%) that a change in cardiac function has taken place.

No abstract