ARDSNCT06823804
Electrical Impedance Tomography-Derived Dorsal Recruitment-to-Inflation Ratio Identifies PEEP Responsiveness and Risk Phenotypes in ARDS
An observational study of ARDS, run by Ruijin Hospital at 1 site in China.
Trial summary
In the treatment of critically ill patients, mechanical ventilation is a key link, and appropriate mechanical ventilation strategies can open the alveoli and improve oxygenation, while inappropriate mechanical ventilation can increase lung injury and seriously affect the prognosis. Read more about this study
- Who is it for?
- Ages 18 to 90 years
- Conditions the study is for
- ARDS
- What is being tested?
- Electrical Impedance tomography Monitoring
- How many people
- 120 participants
- Where
- 1 siteChina
- Study dates
- 1 Dec 2022to 31 Dec 2024
- How long will I take part?
- 30 Days
- Phase
- Observational
- 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 to 90 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: This study included adult patients (≥18 years) with moderate-to-severe acute respiratory distress syndrome (ARDS) who were receiving invasive mechanical ventilation in the intensive care unit (ICU) of Ruijin Hospital. All enrolled patients met the Berlin definition of ARDS and had a PaO₂/FiO₂ ratio ≤200 mmHg within 6 hours of screening. A total of 120 patients were consecutively enrolled from December 2022 to December 2024. Patients were stratified by airway closure status for subgroup analyses.
Who may be able to join
- Patients who meet the Berlin definition of ARDS and have been treated with mechanical ventilation (clinical diagnosis of ARDS by the attending ICU physician)
- PaO₂/FiO₂ ≤200 mmHg
Who cannot join
- Age< 18 or >90 years
- Pneumothorax, pneumomediastinum
- Hemodynamic instability (rising vasopressor need in <6h)
- Contraindications to RM or EIT
Trial locations and contacts
1 site in 1 country.
China1 site
Department of Critical Care Medicine，Ruijin Hospital，Shanghai Jiao Tong University School of Medicine，Shanghai，China.
Shanghai, Shanghai Municipality, 200025
About this study
In the treatment of critically ill patients, mechanical ventilation is a key link, and appropriate mechanical ventilation strategies can open the alveoli and improve oxygenation, while inappropriate mechanical ventilation can increase lung injury and seriously affect the prognosis. Ventilator-related lung injury is mainly concentrated in barotrauma, volumetric injury, shear injury, and biological injury, and the monitoring of respiratory ventilation to the level of local ventilation can help to better assess the state of alveolar opening and alveolar collapse, and help to understand the uniformity of gas distribution in the lungs, which is closely related to lung injury. However, how to achieve simple, bedside and real-time lung ventilation and lung volume assessment in clinical work has always been a difficult problem to be overcome. This study intends to explore the changes of local ventilation and blood flow in the lungs during PEEP trail in patients with ARDS monitored by EIT.
Read the detailed description
- Background and Rationale ARDS is associated with heterogeneous lung collapse. The recruitment-to inflation (R/I) ratio has emerged as an index of recruitability, but is usually assessed globally. Electrical impedance tomography (EIT) enables regional assessment of ventilation and may provide more precise determinations of recruitable lung regions, particularly dorsal areas.
- Objectives Primary objective: To compare the predictive value of regional (dorsal and ventral) versus global R/I for recruitment success in moderate-severe ARDS. Secondary objectives: To classify recruitment phenotypes and evaluate associations with oxygenation, compliance improvement, ventilator-free days, ICU length of stay, and 28-day mortality.
- Study Design Prospective, single-centre observational cohort study in ICU patients with moderate-severe ARDS. All eligible patients undergo standardised recruitment maneuver and EIT monitoring.
- Study Setting Ruijin Hospital, Shanghai Jiao Tong University School of Medicine ICU, December 2022 - December 2024.
- Intervention Standardized PEEP step maneuver from 5 → 15 cmH₂O, maintained for 3 minutes. Continuous EIT monitoring of regional compliance, oxygenation, hemodynamics. Dynamic strain cutoff (>0.6) or adverse events terminate the maneuver. Ventilation mode: volume control, tidal volume 4-6 mL/kg predicted body weight, plateau ≤28-30 cmH₂O, FiO₂ titrated for SpO₂ 88-92%.
- Measurements EIT-derived ΔEELI in dorsal and ventral regions Regional and global compliance (Crec and Crs) R/I calculated: Crec/Crs at baseline PEEP Airway opening pressure by low-flow inflation method Primary outcome: recruitment success (≥10% compliance improvement + ≥20 mmHg PaO₂/FiO₂ increase) Secondary: ventilator-free days, ICU LOS, 28-day mortality, dynamic strain
- Statistical Analysis Plan Distribution check by Shapiro-Wilk. Paired tests for within-patient comparisons. ROC curves and Youden index for cut-off selection. Multivariate regression for mortality risk factors. Bonferroni correction for multiple comparisons.
- Safety Monitoring Terminate RM if: MAP <65 mmHg, SpO₂ <88%, arrhythmia onset, dynamic strain >0.6.
- Conditions
- ARDS
- Being tested
- Electrical Impedance tomography Monitoring
- Keywords
- ventilation/perfusion ratio, Electrical impedance tomography, Acute Respiratory Distress Syndrome
- Medical subject headings
- Respiratory Aspiration, Respiratory Distress Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Electrical Impedance tomography MonitoringDiagnostic test
Standardized PEEP step maneuver from 5 → 15 cmH₂O, maintained for 3 minutes. Continuous EIT monitoring of regional compliance, oxygenation, hemodynamics. Dynamic strain cutoff (>0.6) or adverse events terminate the maneuver.
Ventilation mode: volume control, tidal volume 4-6 mL/kg predicted body weight, plateau ≤28-30 cmH₂O, FiO₂ titrated for SpO₂ 88-92%.
| Study group | Role | What they receive |
|---|---|---|
| evaluate the feasibility of using EIT to calculate regional recruitment-to-inflation (R/I) ratios | Regional R/I ratios were computed for the global lung, dorsal (dependent), and ventral (non-dependent) regions of interest (ROIs), which were defined as 50% of the ventro-dorsal lung diameter based on EIT imaging.compare the predictive value of regional (dorsal and ventral) versus global R/I for recruitment success in moderate-severe ARDS. Receives: Diagnostic Test: Electrical Impedance tomography Monitoring |
What is being measured
The primary outcome is the main question the study is designed to answer.
recruitment success percent
recruitment( ≥10% compliance improvement ) and Re-check the blood gas ≥20 mmHg PaO₂/FiO₂ increase mean success
Measured: From enrollment to the end of treatment at 7 days
Secondary outcomes (4)
28-day mortality
Statistical analysis of 28-day mortality
Measured: From enrollment to the end of treatment at 28 days
Ventilator-free days at Day 28
Number of days alive and free from mechanical Ventilation with in the first days after enrollment
Measured: From enrollment to the end of treatment at 28 days
Length of ICU stay
Length of ICU stay in days
Measured: From enrollment to the end of treatment at 7 days
Change in Sequential Organ Failure Assessment (SOFA) score from baseline to day 7
Change in Sequential Organ Failure Assessment (SOFA) score from baseline to day 7
Measured: From enrollment to the end of treatment at 7 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Feb 2025
- Study start1 Dec 2022
- Primary completion31 Dec 2024
- Study completion31 Dec 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ARDSStudies of the same condition, open and under way.
- More trials run by Ruijin HospitalThe sponsor's other registered studies.
- 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
- Observational
- Observational model
- Case only
- Time perspective
- Prospective
- Enrolment
- 120 participants (actual)
- Target duration
- 30 Days
Sponsor and investigators
- Lead sponsor
- Ruijin Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Hongping Qu, Study chair, Department of Critical Care Medicine，Ruijin Hospital，Shanghai Jiao Tong University School of MedicineJialin Liu, Principal investigator, Department of Geriatrics，Ruijin Hospital，Shanghai Jiao Tong University School of Medicinerui zhang, Study director, Department of Critical Care Medicine，Ruijin Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06823804
- Sponsor's protocol ID
- 2022325
- Status last verified
- Dec 2024
- First submitted
- 25 Dec 2024
- Last updated
- 23 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Electrical Impedance Tomography-Derived Dorsal Recruitment-to-Inflation Ratio Identifies PEEP Responsiveness and Risk Phenotypes in ARDS
- ClinicalTrials.gov ID
- NCT06823804
- Acronym / sponsor ID
- 2022325
- Conditions
- ARDS
- Keywords
- ventilation/perfusion ratio, Electrical impedance tomography, Acute Respiratory Distress Syndrome
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 120 participants (actual)
- Lead sponsor
- Ruijin HospitalUniversity, hospital or other
- Study start
- 1 Dec 2022 (actual)
- Primary completion
- 31 Dec 2024 (actual)
- Study completion
- 31 Dec 2024 (actual)
- First posted
- 12 Feb 2025 (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.
In the treatment of critically ill patients, mechanical ventilation is a key link, and appropriate mechanical ventilation strategies can open the alveoli and improve oxygenation, while inappropriate mechanical ventilation can increase lung injury and seriously affect the prognosis. Ventilator-related lung injury is mainly concentrated in barotrauma, volumetric injury, shear injury, and biological injury, and the monitoring of respiratory ventilation to the level of local ventilation can help to better assess the state of alveolar opening and alveolar collapse, and help to understand the uniformity of gas distribution in the lungs, which is closely related to lung injury. However, how to achieve simple, bedside and real-time lung ventilation and lung volume assessment in clinical work has always been a difficult problem to be overcome. This study intends to explore the changes of local ventilation and blood flow in the lungs during PEEP trail in patients with ARDS monitored by EIT.
Detailed description
- Background and Rationale ARDS is associated with heterogeneous lung collapse. The recruitment-to inflation (R/I) ratio has emerged as an index of recruitability, but is usually assessed globally. Electrical impedance tomography (EIT) enables regional assessment of ventilation and may provide more precise determinations of recruitable lung regions, particularly dorsal areas.
- Objectives Primary objective: To compare the predictive value of regional (dorsal and ventral) versus global R/I for recruitment success in moderate-severe ARDS. Secondary objectives: To classify recruitment phenotypes and evaluate associations with oxygenation, compliance improvement, ventilator-free days, ICU length of stay, and 28-day mortality.
- Study Design Prospective, single-centre observational cohort study in ICU patients with moderate-severe ARDS. All eligible patients undergo standardised recruitment maneuver and EIT monitoring.
- Study Setting Ruijin Hospital, Shanghai Jiao Tong University School of Medicine ICU, December 2022 - December 2024.
- Intervention Standardized PEEP step maneuver from 5 → 15 cmH₂O, maintained for 3 minutes. Continuous EIT monitoring of regional compliance, oxygenation, hemodynamics. Dynamic strain cutoff (>0.6) or adverse events terminate the maneuver. Ventilation mode: volume control, tidal volume 4-6 mL/kg predicted body weight, plateau ≤28-30 cmH₂O, FiO₂ titrated for SpO₂ 88-92%.
- Measurements EIT-derived ΔEELI in dorsal and ventral regions Regional and global compliance (Crec and Crs) R/I calculated: Crec/Crs at baseline PEEP Airway opening pressure by low-flow inflation method Primary outcome: recruitment success (≥10% compliance improvement + ≥20 mmHg PaO₂/FiO₂ increase) Secondary: ventilator-free days, ICU LOS, 28-day mortality, dynamic strain
- Statistical Analysis Plan Distribution check by Shapiro-Wilk. Paired tests for within-patient comparisons. ROC curves and Youden index for cut-off selection. Multivariate regression for mortality risk factors. Bonferroni correction for multiple comparisons.
- Safety Monitoring Terminate RM if: MAP <65 mmHg, SpO₂ <88%, arrhythmia onset, dynamic strain >0.6.
Study design
- Observational model
- Case only
- Time perspective
- Prospective
- Target follow-up
- 30 Days
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| evaluate the feasibility of using EIT to calculate regional recruitment-to-inflation (R/I) ratios | – | Diagnostic Test: Electrical Impedance tomography MonitoringRegional R/I ratios were computed for the global lung, dorsal (dependent), and ventral (non-dependent) regions of interest (ROIs), which were defined as 50% of the ventro-dorsal lung diameter based on EIT imaging.compare the predictive value of regional (dorsal and ventral) versus global R/I for recruitment success in moderate-severe ARDS. |
Who may qualify
- Ages
- 18 to 90 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- This study included adult patients (≥18 years) with moderate-to-severe acute respiratory distress syndrome (ARDS) who were receiving invasive mechanical ventilation in the intensive care unit (ICU) of Ruijin Hospital. All enrolled patients met the Berlin definition of ARDS and had a PaO₂/FiO₂ ratio ≤200 mmHg within 6 hours of screening. A total of 120 patients were consecutively enrolled from December 2022 to December 2024. Patients were stratified by airway closure status for subgroup analyses.
Key inclusion criteria (2 listed)
- Patients who meet the Berlin definition of ARDS and have been treated with mechanical ventilation (clinical diagnosis of ARDS by the attending ICU physician)
- PaO₂/FiO₂ ≤200 mmHg
Key exclusion criteria (4 listed)
- Age< 18 or >90 years
- Pneumothorax, pneumomediastinum
- Hemodynamic instability (rising vasopressor need in <6h)
- Contraindications to RM or EIT
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 |
|---|---|---|
| Electrical Impedance tomography MonitoringStandardized PEEP step maneuver from 5 → 15 cmH₂O, maintained for 3 minutes. Continuous EIT monitoring of regional compliance, oxygenation, hemodynamics. Dynamic strain cutoff (>0.6) or adverse events terminate the maneuver. Ventilation mode: volume control, tidal volume 4-6 mL/kg predicted body weight, plateau ≤28-30 cmH₂O, FiO₂ titrated for SpO₂ 88-92%. | Diagnostic test | evaluate the feasibility of using EIT to calculate regional recruitment-to-inflation (R/I) ratios |
Primary outcome
recruitment success percent
Time frame: From enrollment to the end of treatment at 7 days
recruitment( ≥10% compliance improvement ) and Re-check the blood gas ≥20 mmHg PaO₂/FiO₂ increase mean success
4 secondary outcomes
28-day mortality
Time frame: From enrollment to the end of treatment at 28 days
Ventilator-free days at Day 28
Time frame: From enrollment to the end of treatment at 28 days
Length of ICU stay
Time frame: From enrollment to the end of treatment at 7 days
Change in Sequential Organ Failure Assessment (SOFA) score from baseline to day 7
Time frame: From enrollment to the end of treatment at 7 days
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Apr 2026.
- Individual participant dataSharing planned: No
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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.
Hongping Qu study chair
Department of Critical Care Medicine，Ruijin Hospital，Shanghai Jiao Tong University School of Medicine
Jialin Liu principal investigator
Department of Geriatrics，Ruijin Hospital，Shanghai Jiao Tong University School of Medicine
rui zhang study director
Department of Critical Care Medicine，Ruijin Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of ARDS, run by Ruijin Hospital at 1 site in China.
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 2 inclusion and 4 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: finished, as of the sponsor's last update on 23 Apr 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 China. 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 is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
recruitment success percent (time frame: From enrollment to the end of treatment at 7 days). 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 23 Apr 2026.