Early EIT-Guided PEEP Titration on Pulmonary Physiology in Patients With Moderate-to-Severe ARDS Undergoing Prone Positioning (EIT-PEEP-PRONE) (EIT-PEEP-PRONE)

August 26, 2026 updated by: XIE MIN

A Randomized Controlled Trial of Early EIT-Guided PEEP Titration on Pulmonary Physiology in Moderate-to-Severe ARDS Patients Undergoing Prone Positioning

Background: Electrical impedance tomography (EIT)-guided PEEP titration has been shown to improve regional ventilation distribution, increase respiratory system compliance, and reduce mechanical power in patients with acute respiratory distress syndrome (ARDS), but its effect on mortality remains unproven. In patients with moderate-to-severe ARDS, prone positioning for 4 hours allows pulmonary ventilation and perfusion to reach a new steady state, with optimization of ventilation-perfusion (V/Q) matching and other pulmonary physiological parameters. However, whether dynamic PEEP titration guided by EIT at this time point can further optimize V/Q matching and other pulmonary physiological parameters compared with conventional methods has not been reported.

Objective: To investigate whether EIT-guided PEEP titration performed at 4 hours after prone positioning initiation can further optimize V/Q matching and other pulmonary physiological parameters in patients with moderate-to-severe ARDS undergoing prone positioning.

Methods: This is a prospective, single-center, randomized, open-label, parallel-controlled physiological study. A total of 40 patients with moderate-to-severe ARDS (Berlin definition, PaO₂/FiO₂ < 150 mmHg) will be enrolled and randomized in a 1:1 ratio to either the EIT-guided group or the control group. PEEP intervention will be performed at 4 hours after prone positioning initiation (T1) in both groups: the EIT group receives EIT-guided PEEP titration, while the control group receives PEEP set according to the ARDSNet/PEEP-FiO₂ table. The primary outcome is V/Q matching percentage assessed by EIT at 18 hours of prone positioning (T2) and 6 hours after supine repositioning (T3). Secondary outcomes include respiratory mechanics, EIT-derived parameters (regional ventilation distribution, global inhomogeneity index, center of ventilation), oxygenation indices, echocardiographic measures of cardiac function, and clinical outcomes (28-day mortality, ventilator-free days, ICU length of stay, etc.).

Conclusion: This study will provide physiological evidence for early EIT-guided PEEP titration in patients with moderate-to-severe ARDS undergoing prone positioning, and will lay the foundation for future large-scale clinical trials.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

40

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: Min Xie, MD, PhD
  • Phone Number: +86-27-83665204
  • Email: Xie_m@126.com

Study Contact Backup

Study Locations

  • China
    • Hubei
      • Wuhan, Hubei, China, 430030
        • Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology
        • Contact:

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:

  1. Diagnosis of moderate-to-severe ARDS according to the Berlin definition, with a PaO₂/FiO₂ ratio < 150 mmHg on optimal mechanical ventilation.
  2. Clinical decision has been made to place a central venous catheter (internal jugular or subclavian vein) for clinical management.

Exclusion Criteria:

  1. Pregnancy or postpartum state.
  2. BMI > 35 kg/m².
  3. Duration of invasive mechanical ventilation > 48 hours at enrollment.
  4. Severe hemodynamic instability (mean arterial pressure < 65 mmHg on norepinephrine ≥ 0.5 μg/kg/min).
  5. Immediate need for veno-venous extracorporeal membrane oxygenation (VV-ECMO) at enrollment.
  6. Contraindications to prone positioning or EIT monitoring, including but not limited to: facial or cervical trauma; unstable spinal, femoral, pelvic, or rib fractures; recent cardiac surgery; pneumothorax; elevated intracranial pressure; pacemaker or implantable cardioverter-defibrillator; severe chronic lung disease (e.g., severe COPD, asthma, interstitial lung disease); severe cardiac dysfunction (New York Heart Association Class III or IV, acute coronary syndrome, sustained ventricular tachyarrhythmia, or cardiogenic shock).
  7. Lack of informed consent from legally authorized representative.

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: Supportive Care
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: EIT-Guided PEEP Titration Group
PEEP will be titrated using EIT monitoring at 4 hours after prone positioning initiation (T1). The optimal PEEP will be determined at the intersection of the cumulative collapse and overdistension curves, or at the lowest global inhomogeneity index if the intersection occurs between two PEEP levels.
Other: EIT-Guided PEEP Titration Group
PEEP titration is performed during mechanical ventilation to optimize respiratory mechanics and ventilation-perfusion matching in patients with ARDS.
Active Comparator: ARDSNet/PEEP-FiO₂ Table Group
PEEP will be set according to the ARDSNet/PEEP-FiO₂ table at 4 hours after prone positioning initiation (T1).
Other: ARDSNet/PEEP-FiO₂ Table
PEEP will be set according to the ARDSNet/PEEP-FiO₂ table at 4 hours after prone positioning initiation (T1).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Ventilation-Perfusion (V/Q) Matching Percentage
Time Frame: At 18 hours of prone positioning (T2) and at 6 hours after supine repositioning (T3)
V/Q matching percentage assessed by electrical impedance tomography (EIT) using the EIT Evaluation Tool (SDMI) V2.7.1. V/Q matching reflects the efficiency of pulmonary gas exchange and is calculated from regional ventilation and perfusion distribution maps.
At 18 hours of prone positioning (T2) and at 6 hours after supine repositioning (T3)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Respiratory System Compliance
Time Frame: Baseline, T2 (18h prone), and T3 (6h post-supine)
Respiratory system compliance (Crs) calculated as tidal volume divided by driving pressure (plateau pressure minus PEEP), measured under volume-controlled ventilation.
Baseline, T2 (18h prone), and T3 (6h post-supine)
Driving Pressure
Time Frame: At baseline (T0), at 18 hours of prone positioning (T2), and at 6 hours after supine repositioning (T3)
Driving pressure (DP) calculated as plateau pressure (Pplat) minus PEEP, measured under volume-controlled ventilation.
At baseline (T0), at 18 hours of prone positioning (T2), and at 6 hours after supine repositioning (T3)
EIT-Derived Regional Ventilation Distribution
Time Frame: At baseline (T0), at 18 hours of prone positioning (T2), and at 6 hours after supine repositioning (T3)
Regional ventilation distribution assessed by EIT, expressed as percentage of tidal impedance variation in four regions of interest (ROIs): ventral (ROI 1), mid-ventral (ROI 2), mid-dorsal (ROI 3), and dorsal (ROI 4), each corresponding to 25% of the anteroposterior diameter, Center of Ventilation (CoV), Global Inhomogeneity Index (GI), Shunt, Dead Space.
At baseline (T0), at 18 hours of prone positioning (T2), and at 6 hours after supine repositioning (T3)
RVEDA/LVEDA
Time Frame: At baseline (T0) and at 6 hours after supine repositioning (T3)
Right Ventricular End-Diastolic Area to Left Ventricular End-Diastolic Area Ratio
At baseline (T0) and at 6 hours after supine repositioning (T3)
RVFAC
Time Frame: Baseline and 6h post-supine repositioning (T3)
Right Ventricular Fractional Area Change（%）
Baseline and 6h post-supine repositioning (T3)
TAPSE
Time Frame: Baseline and 6h post-supine repositioning (T3)
Tricuspid Annular Plane Systolic Excursion (mm)
Baseline and 6h post-supine repositioning (T3)
TRVmax
Time Frame: Baseline and 6h post-supine repositioning (T3)
Maximal Tricuspid Regurgitation Velocity (m/s)
Baseline and 6h post-supine repositioning (T3)
LVEF
Time Frame: At baseline (T0) and at 6 hours after supine repositioning (T3)
Left Ventricular Ejection Fraction（%）
At baseline (T0) and at 6 hours after supine repositioning (T3)
SV
Time Frame: Baseline and 6h post-supine repositioning (T3)
Stroke Volume（ml）
Baseline and 6h post-supine repositioning (T3)
CO
Time Frame: Baseline and 6h post-supine repositioning (T3)
Cardiac Output (L/min)
Baseline and 6h post-supine repositioning (T3)
28-Day Mortality
Time Frame: At 28 days after enrollment
All-cause mortality within 28 days after enrollment.
At 28 days after enrollment
Ventilator-Free Days at 28 Days
Time Frame: At 28 days after enrollment
Number of days alive and free from invasive mechanical ventilation during the first 28 days after enrollment.
At 28 days after enrollment
ICU Length of Stay
Time Frame: From enrollment through ICU discharge, assessed up to 28 days
Total duration of ICU stay (in days) from enrollment to ICU discharge or death.
From enrollment through ICU discharge, assessed up to 28 days
Incidence of ECMO Use
Time Frame: During the ICU stay, assessed up to 28 days
Proportion of patients requiring veno-venous extracorporeal membrane oxygenation (VV-ECMO) during the ICU stay.
During the ICU stay, assessed up to 28 days
Incidence of Tracheostomy
Time Frame: During the ICU stay, assessed up to 28 days.
Proportion of patients undergoing tracheostomy during the ICU stay.
During the ICU stay, assessed up to 28 days.

Collaborators and Investigators

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

Sponsor

XIE MIN

Investigators

  • Principal Investigator: Min Xie, Tongji hospital

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 (Estimated)

August 31, 2026

Primary Completion (Estimated)

May 20, 2027

Study Completion (Estimated)

June 30, 2027

Study Registration Dates

First Submitted

August 20, 2026

First Submitted That Met QC Criteria

August 26, 2026

First Posted (Actual)

August 28, 2026

Study Record Updates

Last Update Posted (Actual)

August 28, 2026

Last Update Submitted That Met QC Criteria

August 26, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • TJ-IRB202605019

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

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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