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Acute Respiratory Distress SyndromeNCT06181539

Evaluate the Effect of Prone Ventilation on Ventilated-blood Flow Ratio in Patients With ARDS by EIT

An observational study of Acute Respiratory Distress Syndrome and Electrical Impedance Tomography, run by Union Hospital, Tongji Medical College, Huazhong University of Science and Technology at 1 site in China.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

Patients with ARDS often suffer a gravity-dependent alveolar collapse, resulting in a reduction of tidal volume, residual alveolar excessive distension, and ventilator-related lung injury(VILI) induced by unreasonable ventilator setting.Prone ventilation (PPV) improves the gravity-dependent alveolar ventilation and… Read more about this study

Who is it for?
Ages 18 years and older
How many people
94 participants
Where
1 siteChina
Study dates
30 Dec 2023to 1 Jul 2025
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 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Study population: Patients who met inclusion exclusion criteria will implement EIT monitoring at the time of before the prone position, prone position for 16 hours and prone position ending 8h.

Who may be able to join

  • 1. Age ≥18 years. 2. Patients diagnosed with ARDS according to the Berlin definition and need to endotracheal intubated and mechanical ventilated in prone position within 48 hours of endotracheal intubation 3. PaO2/FiO2 < 150 mmHg with positive end-expiratory pressure (PEEP) ≥ 5 cmH2O according to the Berlin definition.

Who cannot join

  • 1. Contraindications of EIT such as chest wound dressing, installation of pacemaker, defibrillator, etc.
  • 2. Unstable vertebral fracture 3. Within 15 days after severe facial trauma or facial surgery 4 within 15 days after tracheal surgery or sternotomy 5. Hemodynamic instability or recent cardiac arrest 6. Increased intraocular pressure. 7. Unstable femoral or pelvic fractures and pelvic external fixation. 8 He had severe chest wall disease and unstable rib fractures. 9 Recent cardiothoracic surgery. 10. Pneumothorax 11. Chronic lung disease: severe obstructive pulmonary disease, severe asthma, interstitial lung disease.
  • 12. Maternal 13. Extracorporeal membrane oxygenation(ECMO) had been administered on admission to the ICU.
  • 14. Intracranial hypertension 15. Pulmonary embolism, acute or chronic right heart failure 16. Severe cardiac dysfunction (New York Heart Association class III or IV, acute coronary syndrome, or sustained ventricular tachyarrhythmia), cardiogenic shock; 17. No informed consent was obtained

Trial locations and contacts

1 site in 1 country.

China1 site

  • Union Hospital, Tongji Medical College, Huazhong University of Science and Technology

    Wuhan, Hubei, 430000

Other trials in China

About this study

Official title: Evaluate the Effect of Prone Ventilation on Ventilated-blood Flow Ratio in Patients With Acute Respiratory Distress Syndrome by Electrical Impedance Tomography

Patients with ARDS often suffer a gravity-dependent alveolar collapse, resulting in a reduction of tidal volume, residual alveolar excessive distension, and ventilator-related lung injury(VILI) induced by unreasonable ventilator setting.Prone ventilation (PPV) improves the gravity-dependent alveolar ventilation and promotes lung recruitment in the gravity-dependent area and improves lung compliance. Previous studies showed that prolonged PPV combined with low tidal volume(LTV) lung protected ventilation can significantly reduce the mortality of patients with moderate to severe ARDS.Although more than 60% of patients with moderate to severe ARDS due to COVID-19 has been widely implemented PPV,studies showed an improvement in oxygenation in patients with ARDS(the P/F radio improved by more than 20% before and after PPV) was 9-77%, that is, That is, some patients are unresponsive to PPV. In addition, some patients showed CO2 responsiveness after PPV(ventilation rate (VR) decreased significantly after PPV).The tools for monitoring the effects of PPV on ventilation and blood flow at bedside are still lacking, Electrical impedance tomography (EIT) is a non-invasive, non-radiative, real-time bedside lung imaging technique that can monitor local lung ventilation distribution. This study intends to use EIT to evaluate pulmonary ventilation, blood flow distribution and local V/Q ratio before and after PPV, as well as to monitor the changes in pulmonary physiology before and after PPV, explore the mechanism of PPV improving oxygenation by combined with the changes in oxygenation, and explore the factors that predict and affect PPV responsiveness.

Read the detailed description

Acute respiratory distress syndrome (ARDS) is presented as acute hypoxemia and pulmonary edema due to the increased permeability of alveolar capillaries. Endothelial damage injury and swelling, microthrombosis, and hypoxic pulmonary vasoconstriction can lead to low pulmonary blood vessels perfusion and even occlusion, while patients with ARDS often suffer a gravity-dependent alveolar collapse, resulting in a reduction of tidal volume, residual alveolar excessive distension, and ventilator-related lung injury(VILI) induced by unreasonable ventilator setting.Prone ventilation (PPV) improves the gravity-dependent alveolar ventilation and promotes lung recruitment in the gravity-dependent area and improves lung compliance. Besides, pulmonary blood perfusion is less affected by gravity distribution, thus the improvement of gravity-dependent alveolar ventilation can significantly reduce shunt, and lung heterogeneity and improve V/Q radio. Previous studies showed that prolonged PPV combined with low tidal volume lung protected ventilation can significantly reduce the mortality of patients with moderate to severe ARDS.Although more than 60% of patients with moderate to severe ARDS due to COVID-19 has been widely implemented PPV,studies showed an improvement in oxygenation in patients with ARDS(the P/F radio improved by more than 20% before and after PPV) was 9-77%, that is, That is, some patients are unresponsive to PPV. In addition, some patients showed CO2 responsiveness after PPV (ventilation rate (VR) decreased significantly after PPV).The tools for monitoring the effects of PPV on ventilation and blood flow at bedside are still lacking, Electrical impedance tomography (EIT) is a non-invasive, non-radiative, real-time bedside lung imaging technique that can monitor local lung ventilation distribution. By injecting hypertonic saline through a central vein catheter, we can obtain lung perfusion images to indicate local lung blood flow distribution. In addition, combined with lung ventilation images, we can evaluate the pulmonary shunt, dead space, V/Q ratio, to better clarify the physiological and pathological status of lung.This study intends to use EIT to evaluate pulmonary ventilation, blood flow distribution and local V/Q ratio before and after PPV, as well as to monitor the changes in pulmonary physiology before and after PPV, explore the mechanism of PPV improving oxygenation by combined with the changes in oxygenation, and explore the factors that predict and affect PPV responsiveness.

Keywords
Acute Respiratory Distress Syndrome, Electrical impedance tomography, prone position ventilation
Medical subject headings
Respiratory Distress Syndrome

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Pulmonary ventilation perfusion(V/Q) ratio after 16 hours of PPV monitored by EIT

    the V/Q radio were monitored by EIT after patients were implemented prone position ventilation(PPV) for 16h. The images of ventilation distribution were collected by EIT, and the images of perfusion distribution were collected by injected 10ml of 10% hypertonic saline through a central vein catheter during inspiratory hold or expiratory hold. The ventilation and perfusion images were analysed by specialized software to obtain the data of V/Q radio.

    Measured: 16 hours after prone position ventilation

Secondary outcomes (18)

  1. Pulmonary ventilation perfusion(V/Q) ratio before PPV monitored by EIT before PPV

    The V/Q radio were monitored by EIT before patients were implemented prone position ventilation(PPV). The images of ventilation distribution were collected by EIT, and the data of perfusion distribution were collected by injected 10ml of 10% hypertonic saline through a central vein catheter during inspiratory hold or expiratory hold. The ventilation and perfusion images were analysed by specialized software to obtain the data of V/Q radio.

    Measured: within 1 hour before preparing PPV

  2. Pulmonary ventilation perfusion(V/Q) ratio after PPV ending 8h monitored by EIT

    the V/Q radio were monitored by EIT 8 hours after prone position ventilation ending.The images of ventilation distribution were collected by EIT, and the data of perfusion distribution were collected by injected 10ml of 10% hypertonic saline through a central vein catheter during inspiratory hold or expiratory hold. The ventilation and perfusion images were analysed by specialized software to obtain the data of V/Q radio.

    Measured: 8 hours hours after prone position ventilation ending

  3. Pulmonary ventilation distribution before PPV, PPV for 16h and 8h after PPV ending

    Pulmonary ventilation distribution were monitored by EIT before PPV, PPV for 16h and 8h after PPV ending. The images of ventilation distribution were collected by EIT and analysed by specialized software to obtain the data.

    Measured: within 1hour before preparing PPV, 16 hours after and 8 hours after PPV ending

  4. Pulmonary perfusion distribution before PPV, PPV for 16h and 8h after PPV ending

    The pulmonary perfusion distribution were monitored by EIT before PPV, PPV for 16h and 8h after PPV ending. The images of perfusion distribution were collected by injected 10ml of 10% hypertonic saline through a central vein catheter during inspiratory hold or expiratory hold. The perfusion images were analysed by specialized software to obtain the data of pulmonary perfusion distribution.

    Measured: within 1 hour before preparing PPV, 16 hours after and 8 hours after PPV ending

  5. Pulmonary shunt percentage before PPV, PPV for 16h and 8h after PPV ending

    The ventilation and perfusion images were analysed by specialized software to obtain the data of pulmonary shunt percentage.

    Measured: within 1 hour before preparing PPV, 16 hours after and 8 hours after PPV ending

  6. Pulmonary dead space percentage before PPV, PPV for 16h and 8h after PPV ending

    The ventilation and perfusion images were analysed by specialized software to obtain the data of pulmonary dead space percentage.

    Measured: within 1 hour before preparing PPV, 16 hours after and 8 hours after PPV ending

  7. Peak pressure before PPV, PPV for 16h and 8h after PPV ending

    Peak pressure data were obtained from ventilators

    Measured: Within 1 hour before preparing PPV, 16 hours after and 8 hours after PPV ending

  8. Plat pressure before PPV, PPV for 16h and 8h after PPV ending

    Plat pressure data were obtained from ventilators

    Measured: Within 1 hour before preparing PPV, 16 hours after and 8 hours after PPV ending

  9. Tidal volume before PPV, PPV for 16h and 8h after PPV ending

    Tidal volume data were obtained from ventilators

    Measured: within 1 hour before preparing PPV, 16 hours after and 8 hours after PPV ending

  10. Driving pressure before PPV, PPV for 16h and 8h after PPV ending

    Driving pressure(DP) data were obtained from ventilators

    Measured: within 1 hour before preparing PPV, 16 hours after and 8 hours after PPV ending

  11. Static compliance(Cs) before PPV, PPV for 16h and 8h after PPV ending

    Cs is equal to tidal volume divided by DP

    Measured: within 1 hour before preparing PPV, 16 hours after and 8 hours after PPV ending

  12. P/F ratio before PPV, PPV for 16h and 8h after PPV ending

    P/F ratio data were obtain from arterial blood gas analysis

    Measured: within 1 hour before preparing PPV, 16 hours after and 8 hours after PPV ending

  13. Carbon dioxide partial pressure(PaCO2) before PPV, PPV for 16h and 8h after PPV ending

    PaCO2 data were obtain from arterial blood gas analysis

    Measured: within 1 hour before preparing PPV, 16 hours after and 8 hours after PPV ending

  14. Ventilatory ratio(VR) before PPV, PPV for 16h and 8h after PPV ending

    VR=[minute ventilation (ml/min)×arterial partial tension of carbon dioxide (mmHg)] / [predicted body weight×100×37.5

    Measured: within 1 hour before preparing PPV, 16 hours after and 8 hours after PPV ending

  15. 28 days mortality

    Mortality of from the day of enrollment to day 28

    Measured: From the day of enrollment to day 28

  16. Ventilator free days(VFD) within 28 days

    The number of ventilator free days for patients from enrollment day to day 28, if patients died within 28 days,VFD was equal to zero.

    Measured: From the day of enrollment to day 28

  17. Mortality in the ICU

    Mortality in the ICU of all participants

    Measured: From the day of enrollment to the day of transfer from the ICU or death，up to 90 days

  18. Length of stay(LOS)

    LOS(length of stay) of hospital

    Measured: From the day of to the day of admitting to hospital to depart from the hospital or death，up to 90 days

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted26 Dec 2023
  2. Study start30 Dec 2023
  3. Primary completion1 Jun 2025
  4. Study completion1 Jul 2025

Resources

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
Cohort
Time perspective
Prospective
Enrolment
94 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06181539
Sponsor's protocol ID
PPVEIT20230502
Status last verified
Sep 2025
First submitted
13 Dec 2023
Last updated
9 Sep 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No

Publications

  • Fan E, Brodie D, Slutsky AS. Acute Respiratory Distress Syndrome: Advances in Diagnosis and Treatment. JAMA. 2018 Feb 20;319(7):698-710. doi: 10.1001/jama.2017.21907.

    PubMed 29466596

  • Gierhardt M, Pak O, Walmrath D, Seeger W, Grimminger F, Ghofrani HA, Weissmann N, Hecker M, Sommer N. Impairment of hypoxic pulmonary vasoconstriction in acute respiratory distress syndrome. Eur Respir Rev. 2021 Sep 15;30(161):210059. doi: 10.1183/16000617.0059-2021. Print 2021 Sep 30.

    PubMed 34526314

  • Guerin C, Albert RK, Beitler J, Gattinoni L, Jaber S, Marini JJ, Munshi L, Papazian L, Pesenti A, Vieillard-Baron A, Mancebo J. Prone position in ARDS patients: why, when, how and for whom. Intensive Care Med. 2020 Dec;46(12):2385-2396. doi: 10.1007/s00134-020-06306-w. Epub 2020 Nov 10.

    PubMed 33169218

  • Guerin C, Reignier J, Richard JC, Beuret P, Gacouin A, Boulain T, Mercier E, Badet M, Mercat A, Baudin O, Clavel M, Chatellier D, Jaber S, Rosselli S, Mancebo J, Sirodot M, Hilbert G, Bengler C, Richecoeur J, Gainnier M, Bayle F, Bourdin G, Leray V, Girard R, Baboi L, Ayzac L; PROSEVA Study Group. Prone positioning in severe acute respiratory distress syndrome. N Engl J Med. 2013 Jun 6;368(23):2159-68. doi: 10.1056/NEJMoa1214103. Epub 2013 May 20.

    PubMed 23688302

  • Kharat A, Simon M, Guerin C. Prone position in COVID 19-associated acute respiratory failure. Curr Opin Crit Care. 2022 Feb 1;28(1):57-65. doi: 10.1097/MCC.0000000000000900.

    PubMed 34750322

  • Scaramuzzo G, Gamberini L, Tonetti T, Zani G, Ottaviani I, Mazzoli CA, Capozzi C, Giampalma E, Bacchi Reggiani ML, Bertellini E, Castelli A, Cavalli I, Colombo D, Crimaldi F, Damiani F, Fusari M, Gamberini E, Gordini G, Laici C, Lanza MC, Leo M, Marudi A, Nardi G, Papa R, Potalivo A, Russo E, Taddei S, Consales G, Cappellini I, Ranieri VM, Volta CA, Guerin C, Spadaro S; ICU-RER COVID-19 Collaboration. Sustained oxygenation improvement after first prone positioning is associated with liberation from mechanical ventilation and mortality in critically ill COVID-19 patients: a cohort study. Ann Intensive Care. 2021 Apr 26;11(1):63. doi: 10.1186/s13613-021-00853-1.

    PubMed 33900484

  • Lee HY, Cho J, Kwak N, Choi SM, Lee J, Park YS, Lee CH, Yoo CG, Kim YW, Lee SM. Improved Oxygenation After Prone Positioning May Be a Predictor of Survival in Patients With Acute Respiratory Distress Syndrome. Crit Care Med. 2020 Dec;48(12):1729-1736. doi: 10.1097/CCM.0000000000004611.

    PubMed 33003079

  • Clarke J, Geoghegan P, McEvoy N, Boylan M, Ni Choileain O, Mulligan M, Hogan G, Keogh A, McElvaney OJ, McElvaney OF, Bourke J, McNicholas B, Laffey JG, McElvaney NG, Curley GF. Prone positioning improves oxygenation and lung recruitment in patients with SARS-CoV-2 acute respiratory distress syndrome; a single centre cohort study of 20 consecutive patients. BMC Res Notes. 2021 Jan 9;14(1):20. doi: 10.1186/s13104-020-05426-2.

    PubMed 33422143

  • Bachmann MC, Morais C, Bugedo G, Bruhn A, Morales A, Borges JB, Costa E, Retamal J. Electrical impedance tomography in acute respiratory distress syndrome. Crit Care. 2018 Oct 25;22(1):263. doi: 10.1186/s13054-018-2195-6.

    PubMed 30360753

  • Wang YX, Zhong M, Dong MH, Song JQ, Zheng YJ, Wu W, Tao JL, Zhu L, Zheng X. Prone positioning improves ventilation-perfusion matching assessed by electrical impedance tomography in patients with ARDS: a prospective physiological study. Crit Care. 2022 May 27;26(1):154. doi: 10.1186/s13054-022-04021-0.

    PubMed 35624489

  • Fan E, Del Sorbo L, Goligher EC, Hodgson CL, Munshi L, Walkey AJ, Adhikari NKJ, Amato MBP, Branson R, Brower RG, Ferguson ND, Gajic O, Gattinoni L, Hess D, Mancebo J, Meade MO, McAuley DF, Pesenti A, Ranieri VM, Rubenfeld GD, Rubin E, Seckel M, Slutsky AS, Talmor D, Thompson BT, Wunsch H, Uleryk E, Brozek J, Brochard LJ; American Thoracic Society, European Society of Intensive Care Medicine, and Society of Critical Care Medicine. An Official American Thoracic Society/European Society of Intensive Care Medicine/Society of Critical Care Medicine Clinical Practice Guideline: Mechanical Ventilation in Adult Patients with Acute Respiratory Distress Syndrome. Am J Respir Crit Care Med. 2017 May 1;195(9):1253-1263. doi: 10.1164/rccm.201703-0548ST.

    PubMed 28459336

  • Bellani G, Laffey JG, Pham T, Fan E, Brochard L, Esteban A, Gattinoni L, van Haren F, Larsson A, McAuley DF, Ranieri M, Rubenfeld G, Thompson BT, Wrigge H, Slutsky AS, Pesenti A; LUNG SAFE Investigators; ESICM Trials Group. Epidemiology, Patterns of Care, and Mortality for Patients With Acute Respiratory Distress Syndrome in Intensive Care Units in 50 Countries. JAMA. 2016 Feb 23;315(8):788-800. doi: 10.1001/jama.2016.0291.

    PubMed 26903337

  • Langer T, Brioni M, Guzzardella A, Carlesso E, Cabrini L, Castelli G, Dalla Corte F, De Robertis E, Favarato M, Forastieri A, Forlini C, Girardis M, Grieco DL, Mirabella L, Noseda V, Previtali P, Protti A, Rona R, Tardini F, Tonetti T, Zannoni F, Antonelli M, Foti G, Ranieri M, Pesenti A, Fumagalli R, Grasselli G; PRONA-COVID Group. Prone position in intubated, mechanically ventilated patients with COVID-19: a multi-centric study of more than 1000 patients. Crit Care. 2021 Apr 6;25(1):128. doi: 10.1186/s13054-021-03552-2.

    PubMed 33823862

Questions about this trial

What is this clinical trial studying?

An observational study of Acute Respiratory Distress Syndrome and Electrical Impedance Tomography, run by Union Hospital, Tongji Medical College, Huazhong University of Science and Technology 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 1 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 9 Sep 2025. 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?

Pulmonary ventilation perfusion(V/Q) ratio after 16 hours of PPV monitored by EIT (time frame: 16 hours after prone position ventilation). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT06181539, which also lists 13 linked publications.

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 9 Sep 2025.

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