Pivotal Evaluation of Abdominal Neuromuscular Electrical Stimulation (VentFree) for Weaning From Mechanical Ventilation (PREVENT)

A Randomized, Sham Controlled, Double-blinded, Multi-center Trial to Evaluate the Efficacy of the VentFree Respiratory Muscle Stimulator to Assist Ventilator Weaning in Critically Ill Patients

The objective of this study is to evaluate the efficacy of the VentFree Respiratory Muscle Stimulator (VentFree) in critically ill adult patients who require invasive mechanical ventilation, when compared to sham.

Study Overview

• Status: Completed
• Conditions: Respiration, Artificial; Ventilators, Mechanical
• Intervention / Treatment: Device: Breath synchronized abdominal FES; Device: Sham breath synchronized abdominal FES

Detailed Description

Approximately 40% of patients who receive invasive ventilation require more than four days of ventilator support. Every additional day of mechanical ventilation results in increased patient morbidity and mortality and increased economic cost. Mechanically ventilated patients often develop expiratory muscle weakness, which has been linked to failed extubation and weaning.

Neuromuscular electrical stimulation (NMES) uses electrical pulses to induce a muscle contraction and has been shown to reduce or retard muscle atrophy. NMES applied to the abdominal wall muscles has been shown to improve respiratory function and assist ventilator weaning in spinal cord injury. Liberate Medical has previously shown that NMES applied to the abdominal wall muscles in synchrony with exhalation is feasible in patients receiving invasive mechanical ventilation. This study is a pivotal evaluation of the efficacy of exhalation synchronized abdominal NMES to assist ventilator weaning in critically ill patients.

• Study Type: Interventional
• Enrollment (Actual): 250
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Australia
  • Clayton, Australia
    • Monash Medical Centre
  • Kingswood, Australia
    • Nepean Hospital
  • Kogarah, Australia
    • St. George Hospital
  • Randwick, Australia
    • Prince of Wales Hospital
  • St Leonards, Australia
    • Royal North Shore Hospital
• France
  • Angers, France, 49933
    • Centre Hospitalier Universitaire d'Angers
  • Lyon, France, 69365
    • Hôpital Saint Joseph Saint Luc
  • Paris, France
    • Pitié-Salpêtrière University Hospital
• Netherlands
  • 's-Hertogenbosch, Netherlands
    • Jeroen Bosch Ziekenhuis (JBZ)
  • Nijmegen, Netherlands
    • Radboud University Medical Center
  • Nijmegen, Netherlands
    • Canisius Wilhelmina Ziekenhuis (CWZ)
  • Rotterdam, Netherlands
    • Erasmus Medical Center
• United States
  • California
    • Long Beach, California, United States, 90807
      • MemorialCare Long Beach Medical Center
  • Florida
    • Jacksonville, Florida, United States, 32206
      • University of Florida College of Medicine - Jacksonville
  • Illinois
    • Hines, Illinois, United States, 60141
      • Edward Hines, Jr. VA Hospital
    • Maywood, Illinois, United States, 60153
      • Loyola University
  • Kentucky
    • Louisville, Kentucky, United States, 40202
      • University of Louisville
  • Massachusetts
    • Boston, Massachusetts, United States, 02111
      • Tufts Medical Center
  • New York
    • New York, New York, United States, 10065
      • Weill Cornell Medicine / New York Presbyterian Hospital
  • Ohio
    • Cincinnati, Ohio, United States, 45221
      • University of Cincinnati
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15260
      • University of Pittsburgh
  • Tennessee
    • Nashville, Tennessee, United States, 37232
      • Vanderbilt University Medical Center
  • Texas
    • Houston, Texas, United States, 77030
      • Baylor College of Medicine
    • Houston, Texas, United States, 77030
      • Houston Methodist Hospital
    • Houston, Texas, United States, 77030
      • Memorial Hermann
    • Houston, Texas, United States, 077030
      • MD Anderson Cancer Center
  • Washington
    • Everett, Washington, United States, 98201
      • Providence Regional Medical Center

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Participant is ≥ 22 years of age.
2. Participant has been receiving invasive mechanical ventilation for ≥ 24 hours.

Exclusion Criteria:

1. Participant has been receiving invasive mechanical ventilation for > 96 hours.
2. Participant is scheduled or expected to be disconnected from mechanical ventilation ≤ 24 hours after enrollment.
3. Participant was intubated for ≥ 24 hours during a prior episode of invasive mechanical ventilation during current hospitalization.
4. Participant has a BMI ≥ 40 Kg/m2.
5. Participant has no contraction of the abdominal wall muscles in response to abdominal FES as determined by ultrasound.
6. Participant has a pre-existing neuromuscular or muscular disorder that could affect the respiratory muscles (e.g., spinal cord injury or Guillain-Barré syndrome).
7. Participant has had open abdominal surgery ≤ 4 weeks prior to enrollment.
8. Participant has open or damaged skin at area of electrode placements.
9. Participant has a pacemaker and/or implanted electronic device.
10. Participant is known or expected to be pregnant. NOTE: A negative urine or blood pregnancy test will be documented during screening for women of child-bearing potential.
11. Participant is actively pharmacologically paralyzed at the time of enrollment. NOTE: Participants receiving neuromuscular blockers may be enrolled after a ≥ 12-hour washout period.
12. Participant is tracheostomized at the time of enrollment.
13. Participant is on home non-invasive ventilation (except for CPAP or BiPAP for obstructive sleep apnea).
14. Participant is receiving or expected to receive comfort measures (palliative, hospice, comfort care, etc.) at the time of screening or enrollment.

15. Participant is participating in any of the following:

    • A study with the same or similar primary endpoint
    • A study investigating electrical stimulation or respiratory muscle therapy
    • Any study in which the investigator determines may interfere with the results of this study
16. Participant is unable or unwilling to comply with protocol requirements, including assessments, tests, and follow-up visits.
17. Participant has any other medical condition which in the opinion of the Investigator will make participation medically unsafe or interfere with the study results.
18. Participant or legally authorized representative is unwilling to provide written informed consent.
19. Participant or legally authorized representative is unable to provide written informed consent.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Sham Comparator: Sham Respiratory Muscle Stimulator; In the sham group, abdominal functional electrical stimulation (FES) will be set to cause sensory stimulation but no muscle contraction. Abdominal FES will be applied with a frequency of 30 hertz (Hz), a pulse width of 350 µs and a stimulation amplitude that does not cause abdominal wall muscle contraction. The stimulation amplitude will initially be set at 10 mA and reduced in steps of 2 milliamp (mA) until no muscle contraction is seen.	Device: Sham breath synchronized abdominal FES; Sham abdominal stimulation will be applied for 30 minutes twice per day (minimum of four hours between stimulation sessions), for a minimum of five days per week, for 28 days or ICU discharge, whichever comes first.
Experimental: VentFree Respiratory Muscle Stimulator; In the VentFree treatment group, abdominal functional electrical stimulation (FES) will be applied with a frequency of 30 hertz (Hz) and a pulse width of 350µs to cause a strong visible or palpable muscle contraction. The stimulation amplitude will be set to 90% of the participant's maximum tolerable level Discomfort associated with the maximum tolerable level will be recorded on the VAS with pain ratings from zero (no pain) to ten (worst pain). In uncommunicative patients, the maximum tolerable level will be determined as the stimulation intensity that results in a BPS >4 or CPOT >2. The stimulation amplitude will be titrated for each participant and each stimulation session. The stimulation amplitude will be evaluated every 10 (± 2) minutes after the start of each stimulation session and adjusted as necessary to maintain a consistent level of visual contraction and to ensure that the stimulation intensity remains within the participant's maximum tolerable level.	Device: Breath synchronized abdominal FES; Active abdominal stimulation will be applied for 30 minutes twice per day (minimum of four hours between stimulation sessions), for a minimum of five days per week, for 28 days or ICU discharge, whichever comes first.; Other Names: VentFree Respiratory Muscle Stimulator

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time from first FES treatment administration to successful liberation during the treatment period of 28 days or until ICU discharge, whichever occurs first.	Successful liberation is defined as disconnection from mechanical ventilation that does not require invasive mechanical ventilation in the subsequent 7 days after disconnection, or until ICU discharge, or until live hospital discharge, whichever occurs first.	From first FES treatment to 28 days or ICU discharge, whichever occurs first

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cough peak flow	Cough peak flow measurement	At 24 hours post-extubation
Maximum expiratory pressure	Maximum expiratory pressure measurement	At 24 hours post-extubation
Incidence of device-related adverse events	Number of device-related adverse events	From date of first FES treatment administration to date of hospital discharge or 90 days after treatment, whichever occurs first
Time from first FES treatment administration to ICU discharge	Duration of first FES treatment administration to ICU discharge	From date of first FES treatment administration to date of ICU discharge or 90 days after treatment, whichever occurs first
Time from first FES treatment administration to hospital discharge	Duration of first FES treatment administration to hospital discharge	From date of first FES treatment administration to date of hospital discharge or 90 days after treatment, whichever occurs first
Incidence of patients who were successfully liberated from mechanical ventilation	Number of of patients who were successfully liberated from mechanical ventilation	From date of first FES treatment administration to date of hospital discharge or 90 days after treatment, whichever occurs first
Incidence of re-intubations	Number of re-intubations	From date of first FES treatment administration to 90 days after treatment
Incidence of readmissions to the ICU	Number of readmissions to the ICU	From date of first FES treatment administration to 90 days after treatment
Incidence of readmissions to the hospital	Number of readmissions to the hospital	From date of first FES treatment administration to 90 days after treatment
Incidence of acute respiratory infections	Number of participants that had diagnosed acute respiratory infections	From date of first FES treatment administration to date of hospital discharge or 90 days after treatment, whichever occurs first
Incidence of hospital acquired infections	Number of participants that had diagnosed hospital acquired infections	From date of first FES treatment administration to date of hospital discharge or 90 days after treatment, whichever occurs first
Incidence of tracheostomy	Number of participants that underwent tracheostomies	From date of first FES treatment administration to date of ICU discharge or 90 days after treatment, whichever occurs first
Mortality	Number of Deaths	From Date of first FES treatment administration to date of hospital discharge or 90 days after treatment, whichever occurs first
Maximum inspiratory pressure	Maximum inspiratory pressure measurement	At 24 hours post-extubation
Mobility as assessed by the ICU Mobility Scale	Mobility assessment score from 0 (participant is unable to move) - 10 (participant is able to walk independently)	Date of ICU discharge or 90 days after treatment, whichever occurs first
Quality of life as assessed by EQ-5D (Quality of Life Survey)	Five (5) level Quality of Life assessment ranging from Level 1 (indicating no problem) to Level 5 (indicating unable to/extreme problems)	At 90 days after treatment

Collaborators and Investigators

• Sponsor: Liberate Medical
• Collaborators: United States Department of Defense
• Investigators: Study Director: Angus Mclachlan, PhD, Liberate Medical

Publications and helpful links

General Publications

• McCaughey EJ, McLachlan AJ, Cai J, Cohen Freue G, Demoule A, Gotur DB, Hill NS, Dimatteo C, Oliva SP, Patel MB, Girard TD, Heunks L. Randomised, sham-controlled, double-blinded, multicentre international trial to evaluate the efficacy of the Ventfree Respiratory Muscle Stimulator to assist ventilator weaning in critically ill patients: a study protocol of a randomised controlled trial. BMJ Open. 2026 Apr 21;16(4):e113540. doi: 10.1136/bmjopen-2025-113540.

Study record dates

Study Major Dates

• Study Start (Actual): February 15, 2024
• Primary Completion (Actual): February 15, 2026
• Study Completion (Actual): May 1, 2026

Study Registration Dates

• First Submitted: January 16, 2023
• First Submitted That Met QC Criteria: February 24, 2023
• First Posted (Actual): March 8, 2023

Study Record Updates

• Last Update Posted (Actual): June 2, 2026
• Last Update Submitted That Met QC Criteria: May 29, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Mechanical Ventilation; Respiratory Muscle Stimulation
• Additional Relevant MeSH Terms: Pathologic Processes; Respiratory Tract Diseases; Respiration Disorders; Pathological Conditions, Signs and Symptoms; Respiratory Aspiration
• Other Study ID Numbers: LM-VF-P3; CDMRP - PR21220 (Other Grant/Funding Number: Department of Defense)

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: Yes
• product manufactured in and exported from the U.S.: Yes