Fluid Responsiveness and Venous Congestion Evolution During Volume Expansion

Fluid responsiveness is a critical determinant guiding fluid therapy in critically ill patients. However, excessive fluid administration can result in fluid overload, leading to venous congestion and worse clinical outcomes. Venous congestion, a marker of impaired fluid clearance, is increasingly recognized as a significant contributor to poor prognosis. Previous studies have demonstrated the coexistence of fluid responsiveness and venous congestion in critically ill patients. Notably, these studies were limited by the absence of fluid challenge-the gold standard for assessing fluid responsiveness-leaving the dynamic relationship between fluid responsiveness and venous congestion incompletely understood. This study aims to investigate the interplay and temporal evolution of fluid responsiveness and venous congestion following a standardized fluid challenge in critically ill patients.