Evaluation of the Association Between Right Atrial Reservoir Strain Variation and Fluid Responsiveness in Patients With Septic Shock

Evaluating preload dependence is crucial for managing fluid administration in septic shock patients. To avoid unnecessary fluid administration, it's recommended to use dynamic tests like the passive leg raising (PLR) maneuver or a fluid challenge (FC) to see if a patient's cardiac output will increase after fluid resuscitation. Transthoracic echocardiography (TTE) is preferred for this because it can non-invasively, reliably, and reproducibly measure the increase in cardiac output. A patient is considered a "responder" if their stroke volume (SV) increases by more than 15% after an FC. Two-dimensional (2D) right atrial strain (RAS) is a promising tool for evaluating right atrial function. According to the Frank-Starling law, measuring changes in the RA reservoir strain phase (RASr) can identify acute changes in preload, like those induced by a PLR maneuver or an FC. The aims of this study are to assess the ability of ∆RASr to identify responders after a fluid challenge (FC) and to evaluate the ability of ∆RASr variation induced by a PLR maneuver to distinguish responders from non-responders to volume expansion.