From Volume Assessment to Flow-Guided Therapy in Kidney Transplantation: A Multimodal Approach

Kidney transplantation is the treatment of choice for end-stage renal disease, although delayed graft function remains a frequent early complication with important clinical implications. Because early graft recovery depends on adequate perfusion, careful perioperative volume assessment and hemodynamic optimization are essential. Conventional markers such as interdialytic weight gain and estimated dry weight provide only indirect information on intravascular volume and may lead to pre-transplant misclassification of volume status. Complementary tools, including bioimpedance, natriuretic peptides, and congestion-focused ultrasound, may improve characterization of fluid distribution and hemodynamic stress, but none reliably define effective graft perfusion. Pressure-based parameters remain central to perioperative management; however, mean arterial pressure reflects systemic perfusion pressure and may be preserved despite reduced renal blood flow. Central venous pressure is an imprecise surrogate of intravascular volume and fluid responsiveness, with inconsistent associations with clinical outcomes across studies. In this context, flow-guided strategies based on dynamic indices of fluid responsiveness provide a more direct assessment of circulatory adequacy and have been associated, in selected studies, with improved early graft outcomes. Overall, the evidence supports a multimodal approach integrating volume assessment tools with pressure- and flow-oriented monitoring to optimize graft perfusion and early transplant outcomes.