The FILTRATE Trial: High-Rate Ultrafiltration for Intravascular Congestion

• High-rate ultrafiltration (Procedure): This intervention consists of fluid removal (ultrafiltration) during the first in-hospital hemodialysis session of a patient with advanced Chronic Kidney Disease, utilizing a high rate greater than 13 mL/kg/h (with a strict safety limit established between >13 and up to 15 mL/kg/h).The differentiating value of this protocol lies in the fact that it challenges traditional medical dogma by combining an aggressive rate with advanced multiparametric ultrasound tools, something that had not been formally structured in previous clinical trials.
• Standard fluid removal (Procedure): Receives a standard fluid removal rate of 10 mL/kg/h.

Primary outcomes

• Safety (Incidence of Intradialytic Hypotension - IDH) [During the interventional hemodialysis session.]: Frequency of episodes defined as a drop in systolic blood pressure (PAS > 20 mmHg) or mean arterial pressure (PAM > 10 mmHg) associated with clinical symptoms requiring medical intervention during the session.
• Ultrasound Efficacy [Comparison between Baseline (pre-intervention) and within 24 hours post-intervention.]: Improvement in intravascular congestion parameters and cardiac filling pressures, evaluated through a reduction of at least 1 grade in the VExUS score, a 30% decrease in the lung B-line count, and improvement in echocardiographic parameters.
• Clinical Respiratory Efficacy [The patient's condition is assessed before starting the therapy, and their clinical progress is evaluated within the 24 hours post-intervention.]: Clinical improvement of the patient measured by the mMRC dyspnea scale and the documented change in the use of supplemental oxygen (fraction of inspired oxygen \[FiO_2\] or flow in liters per minute).

Secondary outcomes

• Prediction and Tolerance Analysis [Pre-session (baseline) ultrasound data are collected and correlated with any adverse events that occur while the ultrafiltration is underway.]: Determining if high baseline VExUS scores and elevated cardiac filling pressures can predict which patients will successfully tolerate the high ultrafiltration rate (>13 mL/kg/h), aiming to establish specific cutoff values using ROC curves.
• Hospital Stay and Support [From the date of randomization until hospital discharge, assessed up to 30 days.]: Measuring and comparing the difference between both groups in total days of hospital stay and days of supplemental oxygen requirement.
• Blood Pressure Control and Volume [Prior to the session (Baseline) and within 24 hours post-intervention.]: Correlating the total volume of ultrafiltration programmed versus the volume achieved at the end of the session, and comparing the impact on blood pressure control (pre-dialysis vs. post-dialysis at 24 hours).
• Biomedical and Echocardiographic Variables [Prior to the session (Baseline) and within 24 hours post-intervention.]: Analyzing the quantitative change in natriuretic peptide (NT-proBNP) levels before and within 24 hours after the session.
• Subgroup Analysis (Ventricular Function) [From the date of randomization until hospital discharge, assessed up to 30 days.]: Exploring whether Left Ventricular Ejection Fraction (LVEF), natriuretic peptides, or pre-dialysis blood pressure modify or influence the clinical response to the specific ultrafiltration profile used

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Adults over 18 years old with End-Stage Renal Disease on hemodialysis for at least 3 months.
* Admitted to the hospital requiring mechanical fluid removal for acute fluid overload (first in-hospital session).
* Clear ultrasound evidence of severe intravascular congestion (such as diffuse B-lines in the lungs or altered VExUS vascular flow patterns).
* Hemodynamically stable with a baseline blood pressure of at least 120/80 mmHg.

Exclusion Criteria:

* Baseline low blood pressure (<100/60 mmHg) or active shock (cardiogenic, septic, or distributive).
* Acute coronary syndrome (heart attack), severe heart valve disease, or severe fluid around the heart.
* Known chronic lung disease.
* Pregnancy.

• Study Protocol (PDF, 2026-05-08)
• Statistical Analysis Plan (PDF, 2026-05-08)
• Informed Consent Form (PDF, 2026-05-08)