Perioperative Hemodynamic Monitoring

In this review, we aimed to provide an overview of hemodynamic monitoring methods used in the perioperative setting. Hemodynamic monitoring tools can be divided into 3 categories: invasive, minimally invasive, and noninvasive monitoring tools. The most invasive tool, the PAC, can be used to assess a multitude of hemodynamic variables, for example, CO, pulmonary artery pressures, systemic vascular resistance, pulmonary vascular resistance, right ventricle end-diastolic volume or ejection fraction, and so on. However, owing to the risks associated with its invasiveness, the use of PAC is limited to select patient populations and procedures (mainly cardiac surgery). It remains unclear if PAC based treatment algorithms improve clinical outcomes. Slightly less invasive is the TPTD technique, which can be used to obtain the CO, GEDV, and EVLW. For arterial blood pressure monitoring, an arterial catheter remains the gold standard and pulse wave analysis can be used to estimate CO, stroke volume, and dynamic indices (stroke volume variation and pulse pressure variation) for predicting fluid responsiveness. Pulse waves can also be derived and analyzed from the noninvasive continuous volume clamp method, which can provide the same hemodynamic variables. The CVP has been used for a long time for assessing fluid responsiveness; however, it has been shown to correlate poorly with the volume status of the patients, and therefore it has been proposed to use dynamic indices instead, obtained either invasively or noninvasively. Besides stroke volume variation and pulse pressure variation, the ΔPOP and PVI can be used to predict fluid responsiveness in the operating room. The Pmsf can be used to accurately assess a patient’s volume status, although it is quite difficult to measure and, thus, is of limited clinical use.