Bioimpedance and Multiparametric Ultrasound-Guided Fluid Management After Kidney Transplantation

After a kidney transplant, the amount of fluid in the body must be carefully balanced. Too much fluid can accumulate in the lungs, the tissues and the new kidney itself and may delay its recovery; too little fluid can also damage it. In current practice, doctors judge fluid status mainly by physical examination, body weight and urine output, which are imprecise and often late signs. Two painless bedside tests can measure fluid status more accurately: bioimpedance, which estimates excess body water through skin electrodes, and ultrasound of the lungs, the large abdominal veins and the transplanted kidney. In a previous study by our group, these tests detected fluid overload that physical examination missed. Whether using their results to guide treatment actually improves the outcome of the transplant is unknown. This trial will compare two ways of managing fluids during the first month after transplantation: one guided by these tests and a treatment algorithm, and one based on usual clinical assessment. The aim is to find out whether test-guided management improves survival, reduces the need for dialysis in the first week and leads to better kidney function at one month.

Inclusion Criteria: * CKD stage 5. * Kidney-only transplant from a deceased donor (brain death or circulatory death, with or without normothermic regional perfusion). * Two-step informed consent. Exclusion Criteria: * Multi-organ transplant. * ICU admission on mechanical ventilation. * Implanted electronic device or major amputation. * Fibrotic lung disease or extensive thoracic dressings. * Cirrhosis with portal hypertension. * Pregnancy. * Another interventional trial on fluids or delayed graft function.