Effect of Systematic and Sequential Leg Elevation on Cardiac Output in Healthy Volunteers

Passive leg raising (PLR) transiently increases venous return and cardiac preload and is commonly used to predict fluid responsiveness in critically ill patients. Repeated fluid boluses contribute to fluid overload in septic shock, whereas PLR may provide similar hemodynamic effects without fluid administration. Before evaluating repeated PLR in septic shock patients, it is necessary to determine whether the cardiac output response to PLR remains present during repeated PLR maneuvers. SYSLE-1 is a prospective interventional physiological crossover study conducted in healthy volunteers. Participants will undergo six consecutive passive leg raising sessions performed either during spontaneous breathing or non-invasive ventilation, in randomized order. The study aims to determine whether the increase in cardiac output induced by the first PLR maneuver persists during repeated PLR sessions.