Volume Removal Intolerance During Net Ultrafiltration in Acute Kidney Injury Patients

NCT07643597 | Not Yet Recruiting

• 1 other identifier: CEC-SST-15-2026
• Study Type: observational
• Target: 128
• Locations: 7 countries
• Sites: 10

Brief Summary

Acute kidney injury (AKI) is common in critically ill patients and is frequently associated with fluid overload, which can worsen clinical outcomes. Continuous renal replacement therapy (CRRT) allows fluid removal through net ultrafiltration (UFNET), but some patients develop hemodynamic instability or signs of poor tissue perfusion during this process. The purpose of this prospective observational study is to evaluate tolerance to net ultrafiltration in critically ill patients with AKI receiving CRRT. The study will assess clinical, hemodynamic, ultrasound, perfusion, and biochemical parameters before and during fluid removal to identify factors associated with ultrafiltration intolerance. The investigators hypothesize that alterations in hemodynamic, perfusion, and congestion-related parameters can identify patients at increased risk of ultrafiltration intolerance before the development of overt hypotension. The results may help improve individualized fluid removal strategies and optimize the safety of CRRT in critically ill patients.

Conditions

Acute Kidney Injury; Fluid Overload; Fluid Overload in Dialysis Patients; Critical Illness; Renal Replacement Therapy for Acute Kidney Injury in ICU

Keywords

Net Ultrafiltration; Continuous Renal Replacement Therapy; Fluid Removal; Ultrafiltration Intolerance; Tissue Hypoperfusion; Fluid Overload; VExUS; Point-of-Care Ultrasound

Outcome Measures

Primary Outcomes (1)

• Development of Ultrafiltration Intolerance

  Proportion of patients who develop ultrafiltration intolerance according to the protocol-defined composite criteria, including hypotension, increased vasopressor requirements, worsening peripheral perfusion, tissue hypoperfusion, or reduction/interruption of ultrafiltration due to instability.

  From UFNET initiation (T0) to 24 hours after initiation of net ultrafiltration

Secondary Outcomes (11)

• Incidence of Ultrafiltration Intolerance

  From UFNET initiation (T0) to 24 hours.

• Net Ultrafiltration Rate (mL/kg/h)

  From UFNET initiation (T0) to 24 hours.

• Time to First Ultrafiltration Intolerance Event (hours)

  From UFNET initiation to 24 hours.

• Severity Category of Ultrafiltration Intolerance

  From UFNET initiation to 24 hours.

• Agreement Between Hypotension-Based and Hypoperfusion-Based Definitions of Ultrafiltration Intolerance

  From UFNET initiation to 24 hours.

Study Arms (1)

AKI Patients Receiving CRRT With Net Ultrafiltration

Adult critically ill patients with acute kidney injury receiving continuous renal replacement therapy with prescribed net ultrafiltration. Participants will be prospectively evaluated using a multiparametric monitoring strategy including clinical, hemodynamic, ultrasound, perfusion, and biochemical assessments. Patients will subsequently be classified according to the development or absence of ultrafiltration intolerance during the observation period.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Adult critically ill patients admitted to participating intensive care units with acute kidney injury requiring continuous renal replacement therapy and prescribed net ultrafiltration as part of routine clinical care.

You may qualify if:

• Age ≥18 years
• Admission to an Intensive Care Unit
• Acute kidney injury according to KDIGO criteria
• Prescription of continuous renal replacement therapy (CRRT) with net ultrafiltration
• Clinical stability considered sufficient to initiate net ultrafiltration according to the treating clinical team

You may not qualify if:

• Chronic kidney replacement therapy prior to ICU admission
• Pregnancy
• Limitation of therapeutic effort or goals-of-care decisions at admission or during the observation period
• Inability to perform hemodynamic or perfusion assessment
• Extracorporeal membrane oxygenation (ECMO)
• Refusal to participate in the study

Sponsors & Collaborators

• Hospital Las Higueras: lead

Study Sites (10)

Hospital Cárdio Pulmonar

Salvador, Brazil

Location

Hospital Clínico Regional de Concepción

Concepción, Chile

Location

Complejo Asistencial Dr. Victor Ríos Ruiz

Los Ángeles, Chile

Location

Hospital Clínico Dra. Eloísa Díaz Insunza de La Florida

Santiago, Chile

Location

Hospital Las Higueras de Talcahuano

Talcahuano, Chile

Location

Hospital Universitario San José de Popayán

Popayán, Colombia

Location

Hospital General Enrique Garces

Quito, Ecuador

Location

Ospedale San Bortolo

Vicenza, Italy

Location

Hospital General de Mexico

Mexico City, Mexico

Location

Hospital Nacional Cayetano Heredia

Lima, Peru

Location

Related Publications (10)

• Ruste M, Delas Q, Fellahi JL, Jacquet-Lagreze M. Perfusion variables and hemodynamic phenotypes during fluid removal via net ultrafiltration in continuous renal replacement therapy: a retrospective single-center cohort study. J Crit Care. 2026 Feb;91:155310. doi: 10.1016/j.jcrc.2025.155310. Epub 2025 Oct 15.

  PMID: 41101138 BACKGROUND

• Bige N, Lavillegrand JR, Dang J, Attias P, Deryckere S, Joffre J, Dubee V, Preda G, Dumas G, Hariri G, Pichereau C, Baudel JL, Guidet B, Maury E, Boelle PY, Ait-Oufella H. Bedside prediction of intradialytic hemodynamic instability in critically ill patients: the SOCRATE study. Ann Intensive Care. 2020 Apr 22;10(1):47. doi: 10.1186/s13613-020-00663-x.

  PMID: 32323060 BACKGROUND

• Wong A, Olusanya O, Watchorn J, Bramham K, Hutchings S. Utility of the Venous Excess Ultrasound (VEXUS) score to track dynamic change in volume status in patients undergoing fluid removal during haemodialysis - the ACUVEX study. Ultrasound J. 2024 Mar 27;16(1):23. doi: 10.1186/s13089-024-00370-9.

  PMID: 38538806 BACKGROUND

• da Hora Passos R, Caldas JR, Ramos JGR, Dos Santos Galvao de Melo EB, Silveira MAD, Batista PBP. Prediction of hemodynamic tolerance of intermittent hemodialysis in critically ill patients: a cohort study. Sci Rep. 2021 Dec 8;11(1):23610. doi: 10.1038/s41598-021-03110-4.

  PMID: 34880359 BACKGROUND

• Douvris A, Zeid K, Hiremath S, Bagshaw SM, Wald R, Beaubien-Souligny W, Kong J, Ronco C, Clark EG. Mechanisms for hemodynamic instability related to renal replacement therapy: a narrative review. Intensive Care Med. 2019 Oct;45(10):1333-1346. doi: 10.1007/s00134-019-05707-w. Epub 2019 Aug 12.

  PMID: 31407042 BACKGROUND

• Ruste M, Sghaier R, Chesnel D, Didier L, Fellahi JL, Jacquet-Lagreze M. Perfusion-based deresuscitation during continuous renal replacement therapy: A before-after pilot study (The early dry Cohort). J Crit Care. 2022 Dec;72:154169. doi: 10.1016/j.jcrc.2022.154169. Epub 2022 Oct 3.

  PMID: 36201978 BACKGROUND

• Bitker L, Dupuis C, Pradat P, Deniel G, Klouche K, Mezidi M, Chauvelot L, Yonis H, Baboi L, Illinger J, Souweine B, Richard JC. Fluid balance neutralization secured by hemodynamic monitoring versus protocolized standard of care in patients with acute circulatory failure requiring continuous renal replacement therapy: results of the GO NEUTRAL randomized controlled trial. Intensive Care Med. 2024 Dec;50(12):2061-2072. doi: 10.1007/s00134-024-07676-1. Epub 2024 Oct 17.

  PMID: 39417870 BACKGROUND

• Ramirez-Guerrero G, Ronco C, Rosner M. Ultrafiltration Tolerance and Improving Outcomes with Continuous Renal Replacement Therapies. Clin J Am Soc Nephrol. 2025 Mar 1;20(3):462-464. doi: 10.2215/CJN.0000000650. Epub 2024 Dec 26. No abstract available.

  PMID: 39724028 BACKGROUND

• Ramirez-Guerrero G, Ronco C. Ultrafiltration Tolerance: A Phenotype That We Need to Recognize. Blood Purif. 2024;53(7):541-547. doi: 10.1159/000537941. Epub 2024 Feb 20.

  PMID: 38377967 BACKGROUND

• Melo P, Ramirez-Guerrero G, Castro R, Wong A, Argaiz ER, Ostermann M, Hernandez G, Kattan E. Ultrafiltration in the critically ill patient: a framework for personalized care. Crit Care. 2026 Jan 24;30(1):87. doi: 10.1186/s13054-026-05836-x.

  PMID: 41580864 BACKGROUND

MeSH Terms

Conditions

Acute Kidney Injury; Edema; Critical Illness

Condition Hierarchy (Ancestors)

Renal Insufficiency; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Disease Attributes; Pathologic Processes

Study Officials

• Gonzalo Ramírez-Guerrero, MD

  Hospital Las Higueras de Talcahuano

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Gonzalo Ramírez-Guerrero, MD

CONTACT

+56981746173; ramirezguerrero.g@gmail.com

Cristian Pedreros-Rosales, MD

CONTACT

cpedreros@me.com

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator - Nephrologist

Study Record Dates

• First Submitted: June 1, 2026
• First Posted: June 11, 2026
• Study Start (Estimated): July 6, 2026
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2027
• Last Updated: June 11, 2026

Record last verified: 2026-06

Locations

IT (1); EC (1); CO (1); PE (1); BR (1); CL (4); ME (1)