Calculating arterial pressure-based cardiac output using a novel measurement and analysis method.

Work on applying physical and physiological principles for determining cardiac output by analysis of pressure measurements has been pursued for decades. Reference measurements for this kind of cardiac output analysis rely on the pulmonary artery catheter (PAC), considered the clinical gold standard for cardiac output monitoring. Recent advances in signal processing, as well as applied information on the relationships that enable arterial pulse pressure to be used to determine stroke volume, have led to the development of a novel system that can continuously measure cardiac output from an arterial pressure waveform that does not require an external calibration reference method. There are significant challenges in applying statistical- and signal-processing practices to the analysis of complex physiological waveforms. This paper reviews the historical basis for measuring flow from the analysis of pressure in a vessel, establishes the physiological and mathematical basis for this new system and describes its performance under various physiological conditions.