External Validation of VVI (E-VVI)

External Validation of the Volume-Velocity Index for Weaning Prediction: a Multicenter Observational Study

Failure of liberation from mechanical ventilation increases days spent being mechanically ventilated, the length of stay and the morbidity of patients. Thus it is crucial that those patients who are ready to be liberated are accurately detected. In this study the investigators want to externally validate an index (the volume-velocity index, VVI) which in a preliminary study was found to predict with high accuracy the outcome of ventilator liberation.

In this study, in patients who are deemed ready to undergo weaning by their treating physician the investigators will measure the excursion of the diaphragm, the principal respiratory muscle, the inspiratory time and the tidal volume and the volume breathed by the patient at each respiration in three phases:

1. during pressure support ventilation with 5/5,
2. during pressure support ventilation with 8/0,
3. during t-tube or pressure support ventilation with 0/0. All of these phases are ventilatory modalities widely used during weaning from mechanical ventilation.

The investigators will evaluate whether VVI can predict accurately the weaning outcome.

Study Overview

• Status: Recruiting
• Conditions: Weaning Mechanical Ventilation

• Study Type: Observational
• Enrollment (Estimated): 100

Contacts and Locations

• Study Contact: Name: Apostolos - Alkiviadis Menis, MD, PhD; Phone Number: +30 2413501280; Email: menis.ap.alk@gmail.com
• Study Contact Backup: Name: Demosthenes Makris; Phone Number: +30 2413501280; Email: dimomakris@med.uth.gr

Study Locations

• Greece
  • Larissa, Greece, 41110
    • Recruiting
    • General University Hospital Of Larissa
    • Contact: Apostolos - Alkiviadis Menis; Phone Number: +30 2413501280; Email: menis.ap.alk@gmail.com
    • Principal Investigator: Apostolos Alkiviadis Menis
  • Thessaloniki, Greece, 57010
    • Not yet recruiting
    • General Hospital of Thessaloniki "G. Papanikolaou"
    • Contact: Christos Karachristos; Phone Number: +30 2313307268; Email: christosk2004@yahoo.gr
    • Principal Investigator: Christos Karachristos
  • Thessaloniki, Greece, 54636
    • Not yet recruiting
    • AHEPA - University General Hospital
    • Contact: Anna Gkiouliava; Phone Number: +30 2310 993 262; Email: annagkio@gmail.com
    • Principal Investigator: Anna Gkiouliava

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Critical Care patients undergoing weaning from mechanical ventilation

Description

Inclusion Criteria:

• Mechanically ventilated patients for more than 48h
• First Spontaneous breathing trial
• Deemed as ready to undergo weaning by the treating physician, according to published readiness criteria (DOI: 10.1183/09031936.00010206)

Exclusion Criteria:

• pregnant patients
• preexisting diaphragmatic disease or injury
• tracheostomy

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Patients undergoing weaning

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Weaning outcome	Validate the predictive capability of VVI for weaning outcome	From the start of the spontaneous breathing trial to failure or success at 48 hours after exubation.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
VVI for SBT or extubation	Comparison of the capability of VVI to predict SBT or extubation failure	From the start of the spontaneous breathing trial to failure or success at 48 hours after exubation.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
VVI vs RSBI	Comparison of the predictive capability of VVI with RSBI for weaning outcome	From the start of the spontaneous breathing trial to failure or success at 48 hours after exubation.
Predictive capability of VVI between long or short ventilation time	Comparison of the redictive capability of VVI between patients ventilated for more than 7 days with patients ventilated for less than 7 days	From the start of the spontaneous breathing trial to failure or success at 48 hours after exubation.
VVI in various SBT modalities	Compare the ability of VVI to predict the weaning outcome in various SBT modalities, namely Pressure Support 8/0 and Pressure Support 5/5 versus t-tube or Pressure Support 0/0	From the start of the spontaneous breathing trial to failure or success at 48 hours after exubation.
Relationship of VVI with MIP and MRC	evaluate the relationship of VVI with indices of strength status such as the maximal inspiratory pressure, for the respiratory muscles, and the medical research council score, for the ICU acquired weakness.	From the start of the spontaneous breathing trial to failure or success at 48 hours after exubation.

Collaborators and Investigators

• Sponsor: University of Thessaly
• Investigators: Principal Investigator: Apostolos - Alkiviadis Menis, General University Hospital Of Larissa; Study Director: Demosthenes Makris, University of Thessaly

Study record dates

Study Major Dates

• Study Start (Actual): December 28, 2025
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): September 1, 2026

Study Registration Dates

• First Submitted: January 19, 2026
• First Submitted That Met QC Criteria: January 19, 2026
• First Posted (Actual): January 28, 2026

Study Record Updates

• Last Update Posted (Actual): February 11, 2026
• Last Update Submitted That Met QC Criteria: February 8, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: mechanical ventilation; ultrasound; weaning
• Other Study ID Numbers: 23/17/16-12-25

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No