Understanding preload reserve using functional hemodynamic monitoring

Excerpt

The assessment of critically ill patients’ cardiovascular state through hemodynamic monitoring is essential to define both stability and change. But monitoring can be improved by maneuvers designed to stress the cardiovascular state. For example, gallop rhythms heard increasing with spontaneous inspiration or associated paradoxical septal shift by echocardiography connote right heart failure. Similarly, tachycardia and near syncope upon sitting up from a supine position connotes hypovolemia. These maneuvers reflect functional bedside tests of the patient’s physiologic reserve. Functional hemodynamic monitoring (FHM) is the process of assessing the dynamic response of a measured hemodynamic variable to a defined, reproducible, and readily reversible extrinsic stress [1]. FHM parameters are commonly used to predict cardiac output responses to volume loading [2, 3], although their applications are broader. …