Effect of Continuous Prolonged Prone Position Versus Intermittent Daily Prone Position in ARDS (ePRONE)

May 14, 2026 updated by: Pontificia Universidad Catolica de Chile

Effect of Continuous Prolonged Prone Position Versus Intermittent Daily Prone Position on Mortality in ARDS Patients: A Multicenter Randomized Controlled Trial

Prone position (placing the patient on his abdomen) has been shown to be an effective intervention to decrease mortality in adults connected to mechanical ventilation for moderate to severe Acute Respiratory Distress Syndrome (ARDS). Patients may require one or more sessions of prone position. However, the optimal duration of prone sessions is unknown. The goal of this clinical trial is to learn if applying prone position in prolonged sessions (> 48 hours - prolonged prone position) is more effective than applying it in daily sessions (16 to 24 hours - intermittent prone position). The trial will also learn about the safety of prolonged prone position compared to intermittent prone position. The main questions it aims to answer are:

  • Does prolonged prone position increase survival compared to intermittent prone position in participants with moderate to severe ARDS ?
  • How does prolonged prone position compare to intermittent prone position in terms of medical problems associated to prone position ?

Researchers will compare prolonged versus intermittent prone position to see which approach is better to treat moderate to severe ARDS.

Participants will:

  • Receive prone position either in prolonged (> 48 hours) or daily (16 to 24 hours) sessions during the first 7 days
  • Be followed for up to 90 days to assess their clinical evolution

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Acute Respiratory Distress Syndrome (ARDS) is a severe condition with a 40% mortality rate. The management of ARDS still relies largely on supportive therapy. The cornerstone of this support is protective mechanical ventilation to prevent ventilator-induced lung injury (VILI). For patients with moderate-to- severe forms of ARDS, specifically mechanically ventilated patients with PaO2/FiO2 ratios below 150, the use of prone position has shown to be a fundamental intervention which became one of the most relevant pillars of the ICU management during the Covid-19 pandemics. Several studies have shown that prone position not only improves oxygenation, but can attenuate the mechanisms of VILI, which would explain its benefit in terms of mortality. The physiologic benefits of prone position are progressive along time, but they can be lost rapidly after returning to supìne position.

Since the publication of the landmark PROSEVA study (Guerin 2013), which showed that ventilating patients in prone position decreased mortality, the standard approach to prone position has been the use of daily sessions of 16 to 20 hours. With this approach most patients usually require 3 to 4 prone sessions (intermittent daily prone position). However, due to the excessive workload of ICU staff during the Covid-19 pandemics, several centers decided to extend the sessions beyond 24 hours to decrease the frequency of position changes in patients with Covid-19 associated ARDS. Several centers reported their experience with prolonged sessions showing that it was feasible and that the rate of adverse events appeared to be similar to those previously reported with the standard daily sessions. The largest experience reported up to now was a retrospective study which included 417 patients from 15 centers in Chile, where a continuous prolonged prone position was applied as a nationwide strategy (Cornejo 2022). Most patients required a single prone session of 4 (3-5) days. Although the study lacked a control group, the mortality and rate of adverse events was rather low compared to other series of patients with similar characteristics. A non-randomized controlled study from 3 hospital in US even showed that compared to patients treated with standard prone sessions (< 24 hours), patients treated with prolonged sessions had a lower risk of mortality (Okin 2023). However, other reports have shown conflicting results regarding the potential benefit associated to prolonging prone position sessions beyond 24 hours. Recent guidelines have acknowledged that the optimal duration of prone position sessions is unknown and must be further investigated (Grasselli 2023). Prolonging prone position sessions may ensure that this lung protective intervention is maintained throughout the acute phase of ARDS.

The goal of the present study is to compare the effects of a continuous prolonged prone position versus an intermittent daily prone position on mortality and other relevant outcomes, as well as on the incidence of adverse events potentially related to prone position, in mechanically ventilated patients with moderate-to-severe ARDS.

The study will be a randomized, multicenter, two-arm parallel-group, investigator-led clinical trial with allocation concealment and intention-to-treat analysis. Patients allocated to the experimental arm (prolonged prone position) will receive prone position sessions for a minimum of 48 hours, which will be further extended until PaO2/FiO2 is ≥ 200, or until reaching the maximum of 120 hours. Patients allocated to the control arm (intermittent prone position) will receive prone position sessions for a minimum of 16 hours and a maximum of 24 hours. In both groups prone sessions may be repeated if PaO2/FiO2 ratio falls below 150 after being returned to supine position during the first 7 days (intervention period).

Study Type

Interventional

Enrollment (Estimated)

780

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Alejandro Bruhn, MD, PhD
  • Phone Number: +56223543292
  • Email: abruhn@uc.cl

Study Contact Backup

Study Locations

  • Argentina
      • Buenos Aires, Argentina
        • Recruiting
        • Sanatorio Güemes
        • Principal Investigator:
          • Ignacio Romero, MD
        • Contact:
      • Buenos Aires, Argentina
        • Recruiting
        • Hospital Britanico
        • Contact:
        • Principal Investigator:
          • Facundo Bianchini, MD
      • Buenos Aires, Argentina
        • Recruiting
        • Sanatorio Mitre
        • Contact:
        • Principal Investigator:
          • Maria Lucia Gimenez, MD
      • La Plata, Argentina
        • Recruiting
        • Hospital San Martin de la Plata, Argentina
        • Contact:
        • Principal Investigator:
          • Mauricio Gastón Nucciarone, MD
      • La Rioja, Argentina
        • Recruiting
        • Hospital Vera Barros
        • Contact:
        • Principal Investigator:
          • Evangelina Zamora, MD
      • Mar del Plata, Argentina
        • Recruiting
        • Hospital Privado de Comunidad
        • Contact:
        • Principal Investigator:
          • Mariano Esperatti, MD
  • Chile
      • Antofagasta, Chile
        • Recruiting
        • Hospital Leonardo Guzmán
        • Contact:
        • Principal Investigator:
          • Vinko Tomicic, MD
      • Chillan, Chile
        • Recruiting
        • Hospital Clínico Herminda Martín
        • Contact:
        • Principal Investigator:
          • Pablo Navarrete, MD
      • Concepción, Chile
        • Recruiting
        • Hospital Guillermo Grant Benavente
        • Contact:
        • Principal Investigator:
          • Paula Fernández, MD
      • Curicó, Chile
        • Recruiting
        • Hospital San Juan de Dios de Curicó
        • Contact:
        • Principal Investigator:
          • Nelson Perez, MD
      • Iquique, Chile
        • Recruiting
        • Hospital Regional Dr. Ernesto Torres Galdames
        • Contact:
        • Principal Investigator:
          • Roberto Galvez, MD
      • Los Ángeles, Chile
        • Recruiting
        • Complejo Asistencial Dr. Victor Ríos Ruiz
        • Contact:
        • Principal Investigator:
          • Fernando Tirapegui, MD
      • Osorno, Chile
        • Recruiting
        • Hospital Base San Jose de Osorno
        • Contact:
        • Principal Investigator:
          • Mario Grage, MD
      • Quilpué, Chile
        • Recruiting
        • Hospital de Quilpué
        • Contact:
        • Principal Investigator:
          • Mario Bruna, MD
      • Rancagua, Chile
      • Santiago, Chile
        • Recruiting
        • Hospital Clínico Universidad de Chile
        • Contact:
        • Principal Investigator:
          • Rodrigo Cornejo, MD
      • Santiago, Chile
        • Recruiting
        • Hospital Padre Hurtado
        • Contact:
        • Principal Investigator:
          • Sofia Leighton, MD
      • Santiago, Chile
        • Recruiting
        • Clinica Las Condes
        • Contact:
        • Principal Investigator:
          • Martin Benites, MD, PhD(c)
      • Santiago, Chile
        • Recruiting
        • Complejo Asistencial Dr. Sótero del Rio
        • Contact:
        • Principal Investigator:
          • Carolina Ruiz, MD
      • Santiago, Chile
        • Recruiting
        • Clinica Santa Maria
        • Contact:
        • Principal Investigator:
          • Tomas Regueira, MD
      • Santiago, Chile
        • Recruiting
        • Hospital Barros Luco
        • Contact:
        • Principal Investigator:
          • Juan Pablo Valdivia, MD
      • Santiago, Chile
        • Recruiting
        • Hospital Clínico UC Christus
        • Contact:
        • Principal Investigator:
          • Roque Basoalto, PT, PhD
      • Santiago, Chile
        • Recruiting
        • Clinica Universidad de Los Andes
        • Contact:
        • Principal Investigator:
          • Juan Castillo, MD
      • Santiago, Chile
        • Recruiting
        • Clinica San Carlos de Apoquindo
        • Contact:
        • Principal Investigator:
          • Rene Medina, PT
      • Santiago, Chile
        • Recruiting
        • Hospital Del Salvador Providencia
        • Contact:
        • Principal Investigator:
          • José Antonio Escalona, MD
      • Santiago, Chile
        • Recruiting
        • Hospital Dra. Eloisa Diaz
        • Contact:
        • Principal Investigator:
          • Eduardo Chinchón, MD
      • Santiago, Chile
        • Recruiting
        • Hospital Santiago Oriente Dr. Luis Tizné Brousse
        • Contact:
        • Principal Investigator:
          • Marco Antonio Merino, MD
      • Temuco, Chile
        • Recruiting
        • Hospital Dr. Hernán Henríquez Aravena
        • Contact:
        • Principal Investigator:
          • Jaime Contreras, MD
      • Valparaíso, Chile
        • Recruiting
        • Hospital Carlos Van Buren
        • Contact:
        • Principal Investigator:
          • Romyna Baghetti@gmail.com, MD
  • Colombia
      • Cundinamarca, Colombia
        • Recruiting
        • Clínica Universidad de La Sabana y Unisabana Center for Translational Science (UCTS) de la Universidad de La Sabana
        • Contact:
        • Principal Investigator:
          • Luis Felipe Reyes, MD
  • Ecuador
      • Quito, Ecuador
        • Recruiting
        • Hospital Eugenio Espejo
        • Contact:
        • Principal Investigator:
          • Manuel Jibaja, MD
  • Mexico
      • Guadalajara, Mexico
        • Recruiting
        • Hospital Civil Fray Antonio Alcalde
        • Contact:
        • Principal Investigator:
          • Miguel Ibarra, MD
      • Mexico City, Mexico
        • Recruiting
        • Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran
        • Contact:
        • Principal Investigator:
          • Silvio Antonio Ñamendys-Silva, MD
      • Mexico City, Mexico
        • Recruiting
        • Hospital Juárez de México
        • Contact:
        • Principal Investigator:
          • Jose Carlos Gasca, MD
      • Mexico City, Mexico
        • Recruiting
        • Instituto Nacional De Enfermedades Respiratorias
        • Contact:
        • Principal Investigator:
          • Irene Balam, MD
      • Querétaro, Mexico
        • Recruiting
        • Hospital General San Juan del Río
        • Contact:
        • Principal Investigator:
          • Orlando Orlando, MD
  • Uruguay
      • Montevideo, Uruguay
        • Recruiting
        • Hospital Español
        • Contact:
        • Principal Investigator:
          • Nicolas Nin, MD
      • Montevideo, Uruguay
        • Recruiting
        • Hospital Pasteur
        • Contact:
        • Principal Investigator:
          • Julio Pontet, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age ≥ 18 years
  • Endotracheal intubation and mechanical ventilation for less than 72 hours

  • Moderate-severe ARDS defined as:

    1. Within 1 week of a known clinical insult or new or worsening respiratory symptoms
    2. Bilateral infiltrates not fully explained by effusions, lobar/lung collapse, or nodules
    3. Respiratory failure not fully explained by cardiac failure or fluid overload
    4. PaO2/FiO2 < 150 mmHg in supine position
  • Prone positioning has been indicated by the attending physician, OR has already been initiated within the last 16 hours

Exclusion Criteria:

  • Contraindications for prone positioning such as intracranial pressure > 20 mmHg, massive hemoptysis, recent tracheal surgery or sternotomy or abdominal surgery with an open wound, recent facial trauma or facial surgery, unstable spine, femur, or pelvic fractures, or a single anterior chest tube with air leaks
  • Patient on extracorporeal membrane oxygenation (ECMO) before randomization
  • Chronic respiratory failure requiring oxygen therapy or non-invasive ventilation (NIV)
  • Known pregnancy
  • Anticipating withdrawal of life support or shift to palliative care

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Intermittent Prone Position
This arm will receive prone position sessions as applied in the PROSEVA trial (Guerin 2013)
Procedure: Daily prone position sessions
Prone position sessions will be extended at least 16 hours, but no longer than 24 hours. Prone sessions will be repeated if PaO2/FiO2 ratio decreases to < 150 after returning to supine position within the first 7 days after randomization. The extension of repeated prone sessions will follow the same criteria.
Experimental: Prolonged Prone Position
This arm will receive prone position sessions as applied in a previous multicenter study during the COVID-19 pandemics (Cornejo 2022)
Procedure: Prolonged prone position sessions
Prone position sessions will be extended at least 48 hours AND until PaO2/FiO2 ratio is ≥ 200, but no longer than 120 hours. Prone sessions will be repeated if PaO2/FiO2 ratio decreases to < 150 after returning to supine position within the first 7 days after randomization. The extension of repeated prone sessions will follow the same criteria.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
28-day mortality
Time Frame: 28 days
All-cause mortality
28 days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
90-day mortality
Time Frame: 90 days
All-cause mortality
90 days
Ventilator-free days
Time Frame: 28 days
Days-free from mechanical ventilation and alive up to day 28
28 days
Hospital-free days at day 28
Time Frame: 28 days
Days-free from Hospital and alive up to day 28
28 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Pontificia Universidad Catolica de Chile

Collaborators

Hospital do Coracao
Fundacion Clinica Valle del Lili
Fondo Nacional de Desarrollo Científico y Tecnológico, Chile

Investigators

  • Principal Investigator: Alejandro Bruhn, MD, PhD, Pontificia Universidad Catolica de Chile
  • Study Director: Rodrigo Cornejo, MD, MBA, University of Chile

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 7, 2025

Primary Completion (Estimated)

October 1, 2027

Study Completion (Estimated)

January 1, 2028

Study Registration Dates

First Submitted

January 21, 2025

First Submitted That Met QC Criteria

February 25, 2025

First Posted (Actual)

March 3, 2025

Study Record Updates

Last Update Posted (Actual)

May 18, 2026

Last Update Submitted That Met QC Criteria

May 14, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 230606007

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

anonymized data will be shared among reasonable request to the corresponding author.

IPD Sharing Time Frame

will become available after the main paper is published, for 10 years.

IPD Sharing Access Criteria

among reasonable request to the principal investigator

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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