Quantification of Systemic Congestion by Ultrasound As a Predictor of Weaning Failure From Mechanical Ventilation

NCT07343882 | Not Yet Recruiting

• 1 other identifier: IIBSP-CCS-2024-185
• Study Type: interventional
• Target: 350
• Locations: 0 countries
• Sites: N/A

Brief Summary

Mechanical ventilation is an essential, life-saving therapy in the ICU, allowing critically ill patients to rest and recover. Transitioning patients back to spontaneous breathing-known as weaning-is clinically challenging. The first attempt, the Spontaneous Breathing Trial (SBT), fails in 10-30% of cases. Identifying the mechanisms behind failure is crucial, as unsuccessful weaning prolongs ICU stay and increases the risk of reintubation, which worsens prognosis. The SCOUT study aims to improve prediction and management of weaning failure. The main objective of the study is to evaluate whether a specific ultrasound-based method, the Venous Excess Ultrasound Score (VExUS), can predict failure of weaning from mechanical ventilation. A key pathophysiological factor is systemic venous congestion. When a patient initiates an SBT, the increased respiratory effort shifts venous return and may precipitate cardiovascular decompensation with pulmonary fluid accumulation, termed weaning-induced pulmonary edema (WIPO). Notably, this may occur even in patients without known cardiac disease. Detecting clinically relevant congestion before SBT is difficult. Fluid balance and body weight are imprecise, physical examination lacks sensitivity, and biomarkers such as NT-proBNP have limited predictive capacity. VExUS offers a promising, non-invasive approach by directly assessing venous flow patterns in major veins (inferior vena cava, hepatic, portal, and renal veins), providing an estimation of systemic venous pressure and congestion. The central hypothesis is that elevated VExUS grades prior to SBT will identify patients at high risk of failure, enabling proactive optimization and potentially improving outcomes. SCOUT is designed as a prospective, multicenter, observational study. Standard clinical management of mechanical ventilation and weaning remains unchanged. After informed consent, baseline data will be obtained immediately before SBT, including vital signs, ventilator parameters, blood sampling, and three non-invasive ultrasound assessments: cardiac, pulmonary, and VExUS. During the 30-120-minute SBT, the patient breathes with reduced ventilatory support while their clinical tolerance is evaluated. At the end of the SBT, selected measurements are repeated. Weaning failure is defined as: early termination of SBT due to intolerance, need for invasive or non-invasive ventilation within 48 h after extubation, or death within 48 h. Data are anonymized and stored securely (REDCap) in compliance with Spanish and EU data protection regulations. The study is low-risk and provides no direct individual benefit, but may benefit future ICU patients by improving weaning strategies and prognostication.

Conditions

Weaning Failure; Pulmonary Edema - Acute; Mechanical Ventilation; POCUS; VExUS

Keywords

Weaning induced pulmonary edema; Venous Excess Ultrasound grading system

Outcome Measures

Primary Outcomes (2)

• Weaning failure

  The primary objective of the SCOUT study is: To evaluate the utility of VExUS to predict weaning failure from mechanical ventilation. Defining the Weaning Failure A patient is considered to have met the primary outcome if they experience any one of the following events: * The Spontaneous Breathing Trial (SBT) is interrupted due to clinical intolerance, requiring reconnexion to mechanical ventilation. * The patient is extubated but requires rescue with mechanical ventilation (either invasive or non-invasive) within the subsequent 48 hours. * The patient is extubated and dies within the subsequent 48 hours.

  From the start of the spontaneous breathing trail to 48 hours after

• Utility of the VExUS score for predicting the failure of weaning from mechanical ventilation

  The primary objective of the SCOUT study is: To evaluate the utility of VExUS to predict weaning failure from mechanical ventilation. The Venous Excess Ultrasound Score (VExUS) is expressed as four grades (0-3): VExUS 0: No congestion VExUS 1: Mild congestion VExUS 2: Moderate congestion VExUS 3: Severe congestion A patient is considered to have met the primary outcome (weaning failure) if they experience any one of the following events: * The Spontaneous Breathing Trial (SBT) is interrupted due to clinical intolerance, requiring reconnexion to mechanical ventilation. * The patient is extubated but requires rescue with mechanical ventilation (either invasive or non-invasive) within the subsequent 48 hours. * The patient is extubated and dies within the subsequent 48 hours.

  From the start of the spontaneous breathing trial to the next 48 hours

Study Arms (1)

Ultrasound study

EXPERIMENTAL

Prior to SBT: A complete set of pulmonary, cardiac, and VExUS ultrasounds will be performed and stored for later analysis by blinded experts. At the end of SBT: repeat pulmonary and cardiac ultrasounds

Diagnostic Test: point of care ultrasound

Interventions

point of care ultrasound DIAGNOSTIC_TEST

Complete set of pulmonary, cardiac, and VExUS ultrasounds

Ultrasound study

Eligibility Criteria

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

You may qualify if:

• Patients aged \> 18 years.
• Admitted to an Intensive Care Unit (ICU).
• Requiring invasive mechanical ventilation for more than 48 hours.
• Meeting the center's standard criteria to begin weaning and undergo an SBT.

You may not qualify if:

• Inadequate ultrasound window for assessment.
• Presence of "do not reintubate" orders.
• Patients with a tracheostomy.
• Presence of atrial fibrillation.
• Diagnosed liver cirrhosis (portal hypertension).
• Absence of qualified personnel to perform the ultrasound at the time of the SBT.
• Denial of informed consent.

Sponsors & Collaborators

• Fundació Institut de Recerca de l'Hospital de la Santa Creu i Sant Pau: lead

Related Publications (7)

• Beaubien-Souligny W, Rola P, Haycock K, Bouchard J, Lamarche Y, Spiegel R, Denault AY. Quantifying systemic congestion with Point-Of-Care ultrasound: development of the venous excess ultrasound grading system. Ultrasound J. 2020 Apr 9;12(1):16. doi: 10.1186/s13089-020-00163-w.

  PMID: 32270297 BACKGROUND

• Ferre A, Guillot M, Lichtenstein D, Meziere G, Richard C, Teboul JL, Monnet X. Lung ultrasound allows the diagnosis of weaning-induced pulmonary oedema. Intensive Care Med. 2019 May;45(5):601-608. doi: 10.1007/s00134-019-05573-6. Epub 2019 Mar 12.

  PMID: 30863935 BACKGROUND

• Zapata L, Vera P, Roglan A, Gich I, Ordonez-Llanos J, Betbese AJ. B-type natriuretic peptides for prediction and diagnosis of weaning failure from cardiac origin. Intensive Care Med. 2011 Mar;37(3):477-85. doi: 10.1007/s00134-010-2101-4. Epub 2010 Dec 9.

  PMID: 21152896 BACKGROUND

• Zapata L, Suarez-Montero JC, Lopez-Garzon PA. Association between diastolic dysfunction and fluid balance in critically ill patients during weaning from mechanical ventilation. Med Intensiva (Engl Ed). 2023 Dec;47(12):708-716. doi: 10.1016/j.medine.2023.05.012. Epub 2023 Jun 26.

  PMID: 37380508 BACKGROUND

• Vignon P. Cardiopulmonary interactions during ventilator weaning. Front Physiol. 2023 Sep 7;14:1275100. doi: 10.3389/fphys.2023.1275100. eCollection 2023.

  PMID: 37745230 BACKGROUND

• Girard TD, Kress JP, Fuchs BD, Thomason JW, Schweickert WD, Pun BT, Taichman DB, Dunn JG, Pohlman AS, Kinniry PA, Jackson JC, Canonico AE, Light RW, Shintani AK, Thompson JL, Gordon SM, Hall JB, Dittus RS, Bernard GR, Ely EW. Efficacy and safety of a paired sedation and ventilator weaning protocol for mechanically ventilated patients in intensive care (Awakening and Breathing Controlled trial): a randomised controlled trial. Lancet. 2008 Jan 12;371(9607):126-34. doi: 10.1016/S0140-6736(08)60105-1.

  PMID: 18191684 BACKGROUND

• Subira C, Hernandez G, Vazquez A, Rodriguez-Garcia R, Gonzalez-Castro A, Garcia C, Rubio O, Ventura L, Lopez A, de la Torre MC, Keough E, Arauzo V, Hermosa C, Sanchez C, Tizon A, Tenza E, Laborda C, Cabanes S, Lacueva V, Del Mar Fernandez M, Arnau A, Fernandez R. Effect of Pressure Support vs T-Piece Ventilation Strategies During Spontaneous Breathing Trials on Successful Extubation Among Patients Receiving Mechanical Ventilation: A Randomized Clinical Trial. JAMA. 2019 Jun 11;321(22):2175-2182. doi: 10.1001/jama.2019.7234.

  PMID: 31184740 BACKGROUND

Central Study Contacts

Luis Zapata, MD PhD

CONTACT

+349329100; lzapata@santpau.cat

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 7, 2026
• First Posted: January 15, 2026
• Study Start: April 1, 2026
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): June 1, 2027
• Last Updated: January 21, 2026

Record last verified: 2025-12