Prone Positioning and Thoracoabdominal Binding on Lung and Muscle Protection in ARDS Patients During Spontaneous Breathing

NCT05826847 | Terminated

• 1 other identifier: 1221829
• Study Type: interventional
• Target: 14
• Locations: 1 country
• Sites: 1

Brief 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). 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.

Conditions

Acute Respiratory Distress Syndrome; ICU Acquired Weakness; Mechanical Ventilation Complication

Outcome Measures

Primary Outcomes (2)

• (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.

  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.

  One hour on each ventilatory strategy

Secondary Outcomes (1)

• (Randomized Crossover Trial Phase) Respiratory Mechanics Variables

  One hour on each ventilatory strategy

Study Arms (3)

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.

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.

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.

Procedure: Thoracoabdominal Binding

Interventions

Prone Positioning PROCEDURE

Prone positioning will be performed according to ICU local protocol with trained provider teams.

Prone Positioning

Thoracoabdominal Binding PROCEDURE

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

Thoracoabdominal Binding

Control PROCEDURE

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.

Control Group

Eligibility Criteria

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

You may qualify if:

• 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

You may not qualify if:

• Unstable hemodynamics
• Tracheostomy
• Abnormal level of consciousness
• Central nervous system injury
• Esophageal varices
• Pregnancy
• 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

Sponsors & Collaborators

• University of Chile: lead
• Fondo Nacional de Desarrollo Científico y Tecnológico, Chile: collaborator

Study Sites (1)

Hospital Clínico Universidad de Chile

Independencia, Chile

Location

MeSH Terms

Conditions

Respiratory Distress Syndrome

Interventions

Prone Position

Condition Hierarchy (Ancestors)

Lung Diseases; Respiratory Tract Diseases; Respiration Disorders

Intervention Hierarchy (Ancestors)

Posture; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Study Officials

• Rodrigo Cornejo

  University of Chile

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: Masking of participants, care providers and investigators was not feasible due to the nature of the interventions (body positioning and thoracoabdominal binding). In the multimodal physiological description, diaphragm ultrasound and conventional electromyography were performed by assessors unaware of the results of the other physiological assessments.
• Purpose: SUPPORTIVE CARE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Full Professor

Model Details: 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.

Study Record Dates

• First Submitted: March 6, 2023
• First Posted: April 24, 2023
• Study Start: December 6, 2023
• Primary Completion: August 28, 2025
• Study Completion: August 28, 2025
• Last Updated: September 28, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL
• Time Frame: Beginning after publication, for 5 years.
• Access Criteria: Researchers with a methodologically sound proposal, after ethics committee approval.

Locations

CL (1)