Acute Respiratory Distress SyndromeNCT05826847
Prone Positioning and Thoracoabdominal Binding on Lung and Muscle Protection in ARDS Patients During Spontaneous Breathing
A study testing Prone Positioning and Thoracoabdominal Binding in people with Acute Respiratory Distress Syndrome and Mechanical Ventilation Complication, run by University of Chile at 1 site in Chile.
Trial summary
Ventilator-induced diaphragmatic dysfunction and intensive care unit (ICU)-acquired weakness are two consequences of prolonged mechanical ventilation and critical illness in patients with acute respiratory distress syndrome (ARDS). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Acute Respiratory Distress Syndrome, Mechanical Ventilation Complication, ICU Acquired Weakness
- What is being tested?
- Prone Positioning and Thoracoabdominal Binding
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 14 participants
- Where
- 1 siteChile
- Study dates
- 6 Dec 2023to 28 Aug 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adult ARDS patients with moderate-severe ARDS on controlled protective mechanical ventilation for more than 2 days (modified from "more than 3 days" by the protocol amendment approved in May 2024)
- Stable hemodynamics
- Level of consciousness enough to initiate spontaneous breathing
Who cannot join
- Unstable hemodynamics
- Tracheostomy
- Abnormal level of consciousness
- Central nervous system injury
- Esophageal varices
- Pregnancy
Show all 13Show fewer
- Contraindications for installation of electrical impedance tomography or nasogastric catheter placement
- Contraindications for prone positioning and thoracoabdominal binding
- Chronic neuromuscular disorders
- Obstructive lung disease; intrinsic positive end-expiratory pressure (PEEP) ≥3 cmH₂O (measured without inspiratory effort);
- Recent-onset sepsis and moderate-to-severe metabolic acidosis;
- Multi-organ failure with high short-term mortality risk
- Clinical evidence of respiratory or hemodynamic instability
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effect of Prone Positioning and Thoracoabdominal Binding on Lung and Muscle Protection in ARDS Patients With ICU-acquired Weakness Transitioning From Controlled to Spontaneous Breathing
Ventilator-induced diaphragmatic dysfunction and intensive care unit (ICU)-acquired weakness are two consequences of prolonged mechanical ventilation and critical illness in patients with acute respiratory distress syndrome (ARDS). Both complicate the process of withdrawing mechanical ventilation, increase hospital mortality and cause chronic disability in survivors. During transition from controlled to spontaneous breathing, these complications of critical illness favor an abnormal respiratory pattern and recruit accessory respiratory muscles which may promote additional lung and muscle injury. The type of ventilatory support and positioning may affect the muscle dysfunction and patient-self-inflicted lung injury at spontaneous breathing onset. In that regard, ARDS patients with ventilator-induced diaphragmatic dysfunction and ICU-acquired weakness who are transitioning from controlled to partial ventilatory support probably present an abnormal respiratory pattern which exacerbates lung and muscle injury. Physiological-oriented ventilatory approaches based on prone positioning or semi recumbent positioning with abdominal binding at spontaneous breathing onset, could decrease lung and muscle injury by favoring a better neuromuscular efficiency, and preventing intense inspiratory efforts and high transpulmonary driving pressures, as well as high-magnitude pendelluft. In the current project, in addition to perform a multimodal description of the severity of ventilator-induced diaphragmatic dysfunction and ICU-acquired weakness in prolonged mechanically ventilated ARDS patients, prone positioning and supine plus thoracoabdominal binding at spontaneous breathing onset will be evaluated.
Read the detailed description
The study was designed in three phases: a multimodal physiological description, a randomized crossover trial, and a pilot randomized trial. The multimodal physiological description and the randomized crossover trial were conducted in the same cohort. The pilot randomized trial was not conducted.
Multimodal Physiological Description Phase: a multimodal physiological description was performed to characterize ICU acquired weakness and ventilator-induced diaphragm dysfunction in prolonged mechanically ventilated ARDS patients at spontaneous breathing onset, in pressure support ventilation mode. The assessments included conventional electromyography (cEMG); electrical activity of the diaphragm; respiratory muscle ultrasound; respiratory flow; tidal volume; airway, esophageal and gastric pressures; and hemodynamic and electrical impedance tomography monitoring. Diaphragm ultrasound and cEMG were performed after the crossover trial, to avoid reducing PEEP and PS to the standardized low values required for diaphragm ultrasound (PEEP and PS of 6 cmH2O) before the crossover conditions, which could alter respiratory mechanics at protocol entry; cEMG findings were not expected to change over this timeframe (amendment approved by IRB No. 45/2024; May 15, 2024).
Randomized Crossover Trial Phase: Patients were asigened in random order to three 60-minute conditions on pressure support ventilation mode: A.- Control group: semi-recumbent position at 45º (previously described as supine at 45º), B.- Thoracoabdominal binding: semi-recumbent position at 45º plus thoracoabdominal binding, C.- Prone positioning (without thoracoabdominal binding). These strategies were performed under individualized PEEP (obtained at the lowest combination of collapse and overdistension according to electrical impedance tomography), with 15-minute washout periods of in assisted/controlled ventilation between conditions.
Pilot Randomized Trial Phase: This phase was designed to randomize patients to one of the three strategies under standard PEEP (ARDSNet strategy), with PET/CT imaging and biomarker analysis. The originally registered enrollment (n = 36) corresponded to this phase. A protocol amendment approved by the local ethics committee in May 2024 established that patients enrolled in this phase were not required to have completed the multimodal description and crossover phases, and reduced the planned sample size to 12 patients due to budgetary and logistical constraints. The phase was ultimately not conducted; the decision not to conduct it was reported to the local ethics committee and approved by the national funding agency.
Enrollment: The target enrollment for the crossover phase (24 patients) was established in the May 2024 protocol amendment. Recruitment was closed after 14 patients had been enrolled.
- Conditions
- Acute Respiratory Distress Syndrome, Mechanical Ventilation Complication, ICU Acquired Weakness
- Being tested
- Prone Positioning, Thoracoabdominal Binding, Control
- Medical subject headings
- Respiratory Distress Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Prone PositioningProcedure or surgery
Prone positioning will be performed according to ICU local protocol with trained provider teams.
Thoracoabdominal BindingProcedure or surgery
Thoracoabdominal binding will be used in semi-recumbent position (at 45º) and titrated to obtain a approximately 20% decrease in chest wall compliance and 1-3 cm H2O increase in end-expiratory gastric pressure during steady-state breathing
ControlProcedure or surgery
ARDS patients at spontaneous breathing onset on pressure support ventilation mode in supine position at 45º degrees, performed under standard PEEP according to ARDSNet strategy and individualized PEEP applied in random order.
| Study group | Role | What they receive |
|---|---|---|
| Control Group | Active comparator | ARDS patients at spontaneous breathing onset on pressure support ventilation mode in semi-recumbent position at 45º degrees, performed under individualized PEEP applied in random order. Receives: Procedure: Control |
| Prone Positioning | Experimental | ARDS patients at spontaneous breathing onset on pressure support ventilation mode in prone position, performed under individualized PEEP applied in random order. Receives: Procedure: Prone Positioning |
| Thoracoabdominal Binding | Experimental | ARDS patients at spontaneous breathing onset on pressure support ventilation mode in semi-recumbent position at 45º degrees using thoracoabdominal binding with the binder's upper edge above the costal margin, performed under individualized PEEP applied in random order. Receives: Procedure: Thoracoabdominal Binding |
What is being measured
The primary outcome is the main question the study is designed to answer.
(Randomized Crossover Trial Phase) Pendelluft Magnitude
Pendelluft magnitude monitored by electrical impedance tomography, analyzed as a continuous variable. Title corrected in September 2026 from "High-Magnitude Pendelluft", as no threshold was prespecified and the sample size calculation was based on a continuous outcome, according to the protocol amendment approved in May 2024.
Measured: One hour on each ventilatory strategy
(Randomized Crossover Trial Phase) Neuromechanical Coupling of the Diaphragm
Ratio between transdiaphragmatic pressure and electrical activity of the diaphragm, measured by an esophageal/gastric catheter. Co-primary outcome with pendelluft magnitude. Prespecified as primary in the ethics-approved protocol and described in the Brief Summary and as a secondary outcome of the Pilot Randomized Trial Phase, but omitted in error from the Crossover Phase outcomes in the original registration. Added in September 2026.
Measured: One hour on each ventilatory strategy
Secondary outcomes (1)
(Randomized Crossover Trial Phase) Respiratory Mechanics Variables
Esophageal pressure swing, gastric pressure, transdiaphragmatic pressure and transpulmonary driving pressure measured by a esophageal/gastric catheter
Measured: One hour on each ventilatory strategy
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Apr 2023
- Study start6 Dec 2023
- Primary completion28 Aug 2025
- Study completion28 Aug 2025
Why it stopped: Recruitment closed before reaching the target sample size (24) due to budgetary and logistical constraints. The planned pilot randomized phase was not conducted for the same reasons.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Acute Respiratory Distress SyndromeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Randomized crossover design. Each patient received three 60-minute conditions under pressure support ventilation (control, thoracoabdominal binding and prone positioning) in random order, under individualized PEEP guided by electrical impedance tomography, with 15-minute washout periods between conditions. A multimodal physiological description was performed in the same cohort. A pilot randomized trial phase with an independent cohort was originally planned but was not conducted.
- Masking
- None (open label)
- Enrolment
- 14 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Chile
- Sponsor type
- University, hospital or other
- Collaborators
- Fondo Nacional de Desarrollo Científico y Tecnológico, Chile
- Responsible party
- Principal investigator, Rodrigo Cornejo, University of Chile
- Investigators
- Rodrigo Cornejo, Principal investigator, University of Chile
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05826847
- Sponsor's protocol ID
- 1221829
- Status last verified
- Sep 2026
- First submitted
- 6 Mar 2023
- Last updated
- 28 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data underlying the published results will be available upon reasonable request to the principal investigator, subject to approval by the local ethics committee and a data use agreement.
Study at a glance
From the registry record, last updated by the sponsor on 28 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Prone Positioning and Thoracoabdominal Binding on Lung and Muscle Protection in ARDS Patients With ICU-acquired Weakness Transitioning From Controlled to Spontaneous Breathing
- ClinicalTrials.gov ID
- NCT05826847
- Acronym / sponsor ID
- 1221829
- Conditions
- Acute Respiratory Distress Syndrome, Mechanical Ventilation Complication, ICU Acquired Weakness
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Recruitment closed before reaching the target sample size (24) due to budgetary and logistical constraints. The planned pilot randomized phase was not conducted for the same reasons.
- Enrolment
- 14 participants (actual)
- Lead sponsor
- University of ChileUniversity, hospital or other
- Collaborators
- Fondo Nacional de Desarrollo Científico y Tecnológico, Chile
- Study start
- 6 Dec 2023 (actual)
- Primary completion
- 28 Aug 2025 (actual)
- Study completion
- 28 Aug 2025 (actual)
- First posted
- 24 Apr 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Ventilator-induced diaphragmatic dysfunction and intensive care unit (ICU)-acquired weakness are two consequences of prolonged mechanical ventilation and critical illness in patients with acute respiratory distress syndrome (ARDS). Both complicate the process of withdrawing mechanical ventilation, increase hospital mortality and cause chronic disability in survivors. During transition from controlled to spontaneous breathing, these complications of critical illness favor an abnormal respiratory pattern and recruit accessory respiratory muscles which may promote additional lung and muscle injury. The type of ventilatory support and positioning may affect the muscle dysfunction and patient-self-inflicted lung injury at spontaneous breathing onset. In that regard, ARDS patients with ventilator-induced diaphragmatic dysfunction and ICU-acquired weakness who are transitioning from controlled to partial ventilatory support probably present an abnormal respiratory pattern which exacerbates lung and muscle injury. Physiological-oriented ventilatory approaches based on prone positioning or semi recumbent positioning with abdominal binding at spontaneous breathing onset, could decrease lung and muscle injury by favoring a better neuromuscular efficiency, and preventing intense inspiratory efforts and high transpulmonary driving pressures, as well as high-magnitude pendelluft. In the current project, in addition to perform a multimodal description of the severity of ventilator-induced diaphragmatic dysfunction and ICU-acquired weakness in prolonged mechanically ventilated ARDS patients, prone positioning and supine plus thoracoabdominal binding at spontaneous breathing onset will be evaluated.
Detailed description
The study was designed in three phases: a multimodal physiological description, a randomized crossover trial, and a pilot randomized trial. The multimodal physiological description and the randomized crossover trial were conducted in the same cohort. The pilot randomized trial was not conducted.
Multimodal Physiological Description Phase: a multimodal physiological description was performed to characterize ICU acquired weakness and ventilator-induced diaphragm dysfunction in prolonged mechanically ventilated ARDS patients at spontaneous breathing onset, in pressure support ventilation mode. The assessments included conventional electromyography (cEMG); electrical activity of the diaphragm; respiratory muscle ultrasound; respiratory flow; tidal volume; airway, esophageal and gastric pressures; and hemodynamic and electrical impedance tomography monitoring. Diaphragm ultrasound and cEMG were performed after the crossover trial, to avoid reducing PEEP and PS to the standardized low values required for diaphragm ultrasound (PEEP and PS of 6 cmH2O) before the crossover conditions, which could alter respiratory mechanics at protocol entry; cEMG findings were not expected to change over this timeframe (amendment approved by IRB No. 45/2024; May 15, 2024).
Randomized Crossover Trial Phase: Patients were asigened in random order to three 60-minute conditions on pressure support ventilation mode: A.- Control group: semi-recumbent position at 45º (previously described as supine at 45º), B.- Thoracoabdominal binding: semi-recumbent position at 45º plus thoracoabdominal binding, C.- Prone positioning (without thoracoabdominal binding). These strategies were performed under individualized PEEP (obtained at the lowest combination of collapse and overdistension according to electrical impedance tomography), with 15-minute washout periods of in assisted/controlled ventilation between conditions.
Pilot Randomized Trial Phase: This phase was designed to randomize patients to one of the three strategies under standard PEEP (ARDSNet strategy), with PET/CT imaging and biomarker analysis. The originally registered enrollment (n = 36) corresponded to this phase. A protocol amendment approved by the local ethics committee in May 2024 established that patients enrolled in this phase were not required to have completed the multimodal description and crossover phases, and reduced the planned sample size to 12 patients due to budgetary and logistical constraints. The phase was ultimately not conducted; the decision not to conduct it was reported to the local ethics committee and approved by the national funding agency.
Enrollment: The target enrollment for the crossover phase (24 patients) was established in the May 2024 protocol amendment. Recruitment was closed after 14 patients had been enrolled.
Study design
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 3
- Model description
- Randomized crossover design. Each patient received three 60-minute conditions under pressure support ventilation (control, thoracoabdominal binding and prone positioning) in random order, under individualized PEEP guided by electrical impedance tomography, with 15-minute washout periods between conditions. A multimodal physiological description was performed in the same cohort. A pilot randomized trial phase with an independent cohort was originally planned but was not conducted.
| Arm | Type | Receives |
|---|---|---|
| Control Group | Active comparator | Procedure: ControlARDS patients at spontaneous breathing onset on pressure support ventilation mode in semi-recumbent position at 45º degrees, performed under individualized PEEP applied in random order. |
| Prone Positioning | Experimental | Procedure: Prone PositioningARDS patients at spontaneous breathing onset on pressure support ventilation mode in prone position, performed under individualized PEEP applied in random order. |
| Thoracoabdominal Binding | Experimental | Procedure: Thoracoabdominal BindingARDS patients at spontaneous breathing onset on pressure support ventilation mode in semi-recumbent position at 45º degrees using thoracoabdominal binding with the binder's upper edge above the costal margin, performed under individualized PEEP applied in random order. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Adult ARDS patients with moderate-severe ARDS on controlled protective mechanical ventilation for more than 2 days (modified from "more than 3 days" by the protocol amendment approved in May 2024)
- Stable hemodynamics
- Level of consciousness enough to initiate spontaneous breathing
Key exclusion criteria (13 listed)
- Unstable hemodynamics
- Tracheostomy
- Abnormal level of consciousness
- Central nervous system injury
- Esophageal varices
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Prone PositioningProne positioning will be performed according to ICU local protocol with trained provider teams. | Procedure or surgery | Prone Positioning |
| Thoracoabdominal BindingThoracoabdominal binding will be used in semi-recumbent position (at 45º) and titrated to obtain a approximately 20% decrease in chest wall compliance and 1-3 cm H2O increase in end-expiratory gastric pressure during steady-state breathing | Procedure or surgery | Thoracoabdominal Binding |
| ControlARDS patients at spontaneous breathing onset on pressure support ventilation mode in supine position at 45º degrees, performed under standard PEEP according to ARDSNet strategy and individualized PEEP applied in random order. | Procedure or surgery | Control Group |
Primary outcome
(Randomized Crossover Trial Phase) Pendelluft Magnitude
Time frame: One hour on each ventilatory strategy
Pendelluft magnitude monitored by electrical impedance tomography, analyzed as a continuous variable. Title corrected in September 2026 from "High-Magnitude Pendelluft", as no threshold was prespecified and the sample size calculation was based on a continuous outcome, according to the protocol amendment approved in May 2024.
(Randomized Crossover Trial Phase) Neuromechanical Coupling of the Diaphragm
Time frame: One hour on each ventilatory strategy
Ratio between transdiaphragmatic pressure and electrical activity of the diaphragm, measured by an esophageal/gastric catheter. Co-primary outcome with pendelluft magnitude. Prespecified as primary in the ethics-approved protocol and described in the Brief Summary and as a secondary outcome of the Pilot Randomized Trial Phase, but omitted in error from the Crossover Phase outcomes in the original registration. Added in September 2026.
1 secondary outcome
(Randomized Crossover Trial Phase) Respiratory Mechanics Variables
Time frame: One hour on each ventilatory strategy
Results and safety
The study was stopped early (reason given: Recruitment closed before reaching the target sample size (24) due to budgetary and logistical constraints. The planned pilot randomized phase was not conducted for the same reasons.). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Sep 2026.
- Individual participant dataSharing planned: Yes. De-identified individual participant data underlying the published results will be available upon reasonable request to the principal investigator, subject to approval by the local ethics committee and a data use agreement.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Rodrigo Cornejo principal investigator
University of Chile
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Prone Positioning and Thoracoabdominal Binding in people with Acute Respiratory Distress Syndrome and Mechanical Ventilation Complication, run by University of Chile at 1 site in Chile.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 28 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Chile. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was stopped early (reason given: Recruitment closed before reaching the target sample size (24) due to budgetary and logistical constraints. The planned pilot randomized phase was not conducted for the same reasons.). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
(Randomized Crossover Trial Phase) Pendelluft Magnitude (time frame: One hour on each ventilatory strategy). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Sep 2026.