LAUSR

Purpose of ReviewThe purpose of this review was to provide an overview of the recent concepts regarding cardiac output measurement devices that utilize non-pulse contour methods, especially in an intraoperative setting. The techniques include inert gas rebreathing method, partial CO2 rebreathing method, impedance cardiography, and its derivative technologies such as electrical velocimetry and bioreactance, transesophageal echocardiography/Doppler, and transthoracic echocardiography/Doppler. We focused on the invasiveness of the devices and their underlying technology.Recent FindingsAlthough various types of cardiac output monitoring devices are available, none of them may be considered as an ideal device in terms of accuracy, trending ability of cardiac output changes, and reproducibility of measurements. There are increasing types of devices applicable for intraoperative use, yet only few data are available regarding the trending ability of cardiac output changes and reproducibility of the measurements. Therefore, the empirical application of these devices for various surgical patients may be done under the consideration of their invasiveness and their underlying technology, and it may provide us with more data over time.SummaryThe non-pulse contour-derived cardiac output measurement devices are classified according to their underlying principles, which closely reflect their advantages and disadvantages in the perioperative setting.