Effects of Bioimpedance-guided Fluid Management in Maintenance Hemodialysis Patients -

The study was designed as a randomized controlled open label and parallel trial, including adult chronic kidney disease (CKD) patients (older than 18 years) on in-center HD for longer than three months in the Dialysis and Transplantation unit of a southern Brazilian University Hospital. The exclusion criteria were less than thrice a week HD session, lower limbs amputation, pregnancy and pacemaker, implantable cardioverter-defibrillator or orthopedic protheses use. All eligible patients or their relatives were asked to sign an informed consent form before inclusion in the trial. The enrollment was performed from September 2019 to September 2021.

The research protocol was approved by the Catholic University of Pelotas Ethics Committee.

The randomization was performed by blocs according to dialysis shifts, using random number table created in Stata 15.1 statistical software (StataCorp, College Station, TX) Participants and researchers were not blinded due to the nature of the intervention. The statistical analysis was performed by a blinded evaluator.

The main outcome was all-cause two-year survival. Secondary outcomes include overall hospitalization rate and according causes, systolic and diastolic BP change (mean of the three last post-dialysis BP measurement - mean of the three first post-dialysis BP measurement), number of anti-hypertensive drug classes used after intervention time.

At inception, eligible patients had their sex, age and dry weigh recorded from electronic clinical records before the randomization to one of two groups: 1) BIS, whose dry weight is evaluated monthly by clinical examination and biannually BIS-guided; 2) CE, whose dry weight is evaluated monthly by clinical examination alone. The follow-up time for primary and secondary outcomes was two years. Data for hospitalizations, deaths, cause of death, and anti-hypertensives in use were collected from the electronical medical registry.