Abstract
Pulmonary artery catheter (PAC) has been widely used for cardiac output and hemodynamic monitoring. However, the clinical usefulness of the PAC has been seriously questioned, because randomized controlled trials showed that using the PAC did not change mortality but rather increased morbidity. Fortunately, several noninvasive alternative technologies to the PAC have emerged. Cardiac output can be approximated by the indirect Fick method applied to carbon dioxide, called partial carbon dioxide rebreathing technique. When minute ventilation is kept constant during mechanical ventilation, the partial carbon dioxide rebreathing technique can provide reliable monitoring of cardiac output. Analysis of arterial pressure waveform has also been proposed to measure beat-by-beat stroke volume and hence continuously measure cardiac output, called pulse contour analysis. Stroke volume variation derived from this technique is proposed to predict fluid responsiveness.
