An interventional study of APRV ventilation with low-level spontaneous breathing and APRV ventilation with high-level spontaneous breathing in Acute Respiratory Distress Syndrome, sponsored by Union Hospital, Tongji Medical College, Huazhong University of Science and Technology. Not yet recruiting at 1 site in China. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-09-01.
Sponsored by Union Hospital, Tongji Medical College, Huazhong University of Science and Technology · Not applicable, Interventional, and Treatment
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Among 146 studies in Respiratory Distress Syndrome with a site in China — 54 open to participants now, 55 under way, 6 of them phase 3. Respiratory Distress Syndrome · China.
Among the 146 studies in Respiratory Distress Syndrome with a site in China, this one is the 76th largest by planned enrollment of the 81 interventional ones that give a count, is one of 14 that started in 2026, is one of 52 with no phase, reaches primary completion later than 26 of the 54 other live ones, and was the 143rd registered.
1,387 studies on the registry are indexed under Respiratory Distress Syndrome; 282 are open to participants now.
Browse Respiratory Distress Syndrome studies →54 of the 146 studies in Respiratory Distress Syndrome with a site in China are open now. Recruiting first, the newest first:
Southeast University, China · Sites in China
Ruijin Hospital · Sites in China
Ages 18+
Southeast University, China · Sites in China
Ages 18+
Southeast University, China · Sites in China
Ages 18+
Bin Du · Sites in China
Ages 18+
A study can be open while its sites in China have not opened yet or have stopped. Only those recruiting at a site in China →
Of the 193 Respiratory Distress Syndrome studies recruiting now, 117 (61%) set no upper age limit and 48 (25%) stop at 75 or younger; 50 take children under 18; 9 take healthy volunteers.
This study: 18 Years to 80 Years · all sexes · no healthy volunteers.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
146 studies; the count open now beside each. This study's row is marked.
A study in two phases is counted once above. Listed by phase, each with its combined phases: Phase 1 10 · Phase 2 16 · Phase 3 7 · Phase 4 5
First in 2006; this study’s year is marked. 14 started in 2026.
By drug class, each counting the studies that test any of its medicines:
This study's planned enrollment of 15 is below the median of 60 across 822 interventional studies indexed under Respiratory Distress Syndrome.
Median enrollment 100 across the 81 interventional studies, 139 across the 65 observational. Of the 52 that completed or were terminated, 3 (6%) have results posted.
This tab as a report to print or save as PDF → With an account.
11 of 146 have an industry lead sponsor. The 10 most frequent:
Union Hospital, Tongji Medical College, Huazhong University of Science and Technology is the lead sponsor of 182 studies on the registry; 145 are open to participants now.
Union Hospital, Tongji Medical College, Huazhong University of Science and Technology has 3 studies filed under Respiratory Distress Syndrome — fewer than ten, so there is no comparison to draw.
17 of the studies in Respiratory Distress Syndrome with a site in China that are under way reach primary completion within a year, 2 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT07342205Phase 3Shanghai University of Traditional Chinese MedicineA Study on the Treatment of Patients With Acute Lung Injury Caused by Sepsis Through Microbiota Transplantation | 2027-06 |
| NCT05624450Phase 3AstraZenecaEfficacy and Safety of Tozorakimab in Patients Hospitalised for Viral Lung Infection Requiring Supplemental Oxygen | 2027-11-04 |
| NCT07798154Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyEffect of Spontaneous Breathing in APRV Mode on Respiratory Physiology of ARDS Patients | 2026-11 |
| NCT07413094Shanghai Yidian Pharmaceutical Technology Development Co., Ltd.Efficacy and Safety of YD0743 Treatment for Sepsis-Associated ARDS | 2026-12 |
| NCT06430554Zhongda HospitalPersonalized Ventilation Based on Ventilation-perfusion Mismatch and Lung Recruitability | 2026-12-30 |
Add all 17 to your calendar (.ics) → With an account.
Among the 146 studies in Respiratory Distress Syndrome with a site in China, from their registry updates:
This tab as a report to print or save as PDF → With an account.
This is a single-center, prospective, randomized, three-period crossover physiological study in adult patients with moderate-to-severe acute respiratory distress syndrome (ARDS, PaO₂/FiO₂ ≤150 mmHg). Each enrolled subject will receive all three APRV ventilation conditions in random sequence: low-level spontaneous breathing (spontaneous minute-ventilation proportion 10%-30%), high-level spontaneous breathing (31%-50%), and fully suppressed spontaneous breathing as control. A 30-minute wash-out period is set between each condition to restore unified physiological baseline. Primary outcome is ventilation-perfusion mismatch percentage (mismatch%) measured by Electrical Impedance Tomography (EIT). Secondary outcomes include EIT-derived pulmonary parameters, respiratory mechanics, hemodynamics, diaphragmatic function and safety profiles. Only short-term, reversible ventilator and sedation adjustments will be performed; routine clinical management remains unchanged throughout the trial.
Acute respiratory distress syndrome (ARDS) is a life-threatening critical respiratory illness characterized by heterogeneous pulmonary injury and severe ventilation-perfusion mismatch. Airway Pressure Release Ventilation (APRV) permits spontaneous breathing throughout the whole respiratory cycle, which may improve regional ventilation-perfusion matching and hemodynamic status. Nevertheless, excessive spontaneous breathing effort may trigger pendelluft phenomenon, augment regional lung strain and precipitate patient-self-inflicted lung injury (P-SILI). To date, the safe intensity range of spontaneous breathing during APRV for moderate-to-severe ARDS patients has not been well defined.
This single-center, randomized 3-period crossover self-controlled physiological trial enrolls ICU adult patients aged 18-80 years, diagnosed with moderate-to-severe ARDS (PaO₂/FiO₂ ≤ 150 mmHg) within 48-hours of invasive mechanical ventilation. After written informed consent obtained from legal surrogates, subjects will first receive a 60-minute baseline ventilation period following ARDSnet low-tidal-volume pressure-control ventilation strategy under deep sedation without spontaneous breathing. Subsequently, every participant will undergo three APRV intervention states in computer-generated random order: Condition A: APRV with low-intensity spontaneous breathing (spontaneous-contributed minute ventilation 10%-30%); Condition B: APRV with high-intensity spontaneous breathing (31%-50%); Condition C: APRV with fully suppressed spontaneous breathing via deep sedation (RASS -4 to -5). Each intervention maintains target spontaneous-breathing intensity for 30-minute stabilization before data collection. A mandatory 30-minute wash-out phase will be implemented between successive interventions to revert subjects back to baseline pressure-control ventilation and sedation status.
Primary endpoint is the comparison of ventilation-perfusion mismatch percentage (mismatch%, calculated as sum of dead-space fraction and shunt fraction) among three states measured by bedside EIT. Secondary endpoints contain multiple EIT quantitative indices, respiratory mechanics parameters (including esophageal-pressure-derived transpulmonary pressure), hemodynamic and right-ventricular function, diaphragmatic ultrasound indices, arterial blood gas variables. Adverse events related to respiratory, circulatory and operational procedures are closely monitored as safety outcomes.
Planned sample size is 14-16 enrolled participants to achieve 12 evaluable subjects completing all three intervention sequences considering dropout rate. All ventilator and sedation modifications are short-term and reversible; standard clinical therapeutic regimens will not be altered except for study-related procedures. After finishing all three intervention periods, ventilator and sedation settings will be returned to clinical team's discretion. Linear mixed-effect models will be applied for statistical analysis of crossover-design data.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
1. Age ≥18 and ≤80 years old. 2. Diagnosed with moderate-to-severe ARDS according to the 2023 global ARDS definition.
3. Within 48 hours of invasive mechanical ventilation. After 1-hour low-tidal-volume pressure-controlled ventilation following ARDSnet strategy, arterial blood gas shows PaO₂/FiO₂ ≤ 150 mmHg.
4. Written is obtained from the patient or their legal surrogate decision-maker after full explanation of the study by the principal investigator or authorized study physician.
Exclusion Criteria:
1. shock defined as persistent hyperlactatemia and/or prolonged capillary refill time, fluid-resistant, requiring norepinephrine ≥ 0.5 μg/kg/min.
2. Severe chronic medical conditions severely affecting cardiopulmonary function: severe , interstitial lung disease, pulmonary embolism, right-heart failure, pulmonary hypertension, or severe arrhythmia.
3. Radiologically confirmed bronchopleural fistula, status post lobectomy, or other major thoracic surgery.
4. to electrical impedance tomography (EIT): extensive chest skin injury or infection, implanted cardiac pacemaker or defibrillator, etc.
5. Contraindications for esophageal manometry placement: esophageal obstruction, perforation, severe esophageal varices, etc.
6. Diaphragmatic hernia, severe chest wall deformity, or significant pulmonary bullae.
7. Significant coagulation abnormalities (PT or prolonged ≥2 times , or INR>2.0) with active bleeding risk.
8. Severe intracranial hypertension (>20 mmHg), severe traumatic brain injury (GCS ≤8), or neuromuscular disorders.
9. Pregnant or breastfeeding women. 10. Patients already receiving ECMO therapy. 11. Expected survival time \<24 hours judged by attending physician. 12. (BMI) >35 kg/m². 13. Previously enrolled in this study or participating in other interventional clinical trials.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Relapsed and refractory
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
APRV ventilation with spontaneous-contributed minute-ventilation proportion maintained at 10%-30%. A stabilization period of 30 minutes is performed before data collection
Device: APRV ventilation with low-level spontaneous breathing
APRV ventilation with spontaneous-contributed minute-ventilation proportion maintained at 31%-50%. A stabilization period of 30 minutes is performed before data collection.
Device: APRV ventilation with high-level spontaneous breathing
APRV ventilation with spontaneous breathing completely suppressed by deep sedation (RASS-4 to -5). A stabilization period of 30 minutes is performed before data collection.
Device: APRV ventilation with fully suppressed spontaneous breathing
APRV ventilation mode, spontaneous-contributed minute-ventilation proportion maintained at 10%-30%. 30-minute stabilization before outcome measurement.
APRV ventilation mode, spontaneous-contributed minute-ventilation proportion maintained at 31%-50%. 30-minute stabilization before outcome measurement.
APRV ventilation mode, spontaneous breathing fully suppressed by deep sedation (RASS-4 to -5). 30-minute stabilization before outcome measurement.
Ventilation-perfusion mismatch percentage (Mismatch%)
Ventilation-perfusion mismatch percentage (Mismatch%), calculated as the sum of dead-space percentage and shunt percentage measured by electrical impedance tomography (EIT). A composite index reflecting overall ventilation-perfusion mismatch, assessed at baseline and under three APRV experimental conditions. Unit: %
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Match percentage(match%)
Match percentage derived from electrical impedance tomography (EIT). Unit: %.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Pendelluft amplitude
Pendelluft amplitude derived from electrical impedance tomography (EIT). Unit: %.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Dead-space percentage
Dead-space percentage derived from electrical impedance tomography (EIT), assessed at baseline and under three APRV experimental conditions. Unit: %.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Shunt percentage
Intrapulmonary shunt percentage derived from electrical impedance tomography (EIT), assessed at baseline and under three APRV experimental conditions. Unit: %.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Global inhomogeneity index (GI)
Global inhomogeneity index (GI) derived from electrical impedance tomography (EIT). Unit: unitless.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period
Center of ventilation (CoV)
Center of ventilation (CoV) derived from electrical impedance tomography (EIT), assessed at baseline and under three APRV experimental conditions. Unit: %.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Tidal recruitment-derecruitment
Tidal recruitment-derecruitment (Tidal R/D) derived from electrical impedance tomography (EIT), assessed at baseline and under three APRV experimental conditions. Unit: %.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Ventilation distribution
Regional ventilation distribution derived from electrical impedance tomography (EIT), assessed at baseline and under three APRV experimental conditions. Unit: %.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Perfusion distribution
Regional pulmonary perfusion distribution derived from electrical impedance tomography (EIT), assessed at baseline and under three APRV experimental conditions. Unit: %.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Peak airway pressure (Ppeak)
Airway peak pressure (Ppeak) measured by mechanical ventilator, assessed at baseline and under three APRV experimental conditions. Unit: cmH₂O
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Plateau pressure (Pplat)
Airway plateau pressure (Pplat) obtained from end-inspiratory hold maneuver, assessed at baseline and under three APRV experimental conditions. Unit: cmH₂O.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Driving pressure (ΔP)
Driving pressure (ΔP) derived from mechanical ventilator measurements. Unit: cmH₂O.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Static respiratory system compliance (Cstat)
Static respiratory system compliance (Cstat), assessed at baseline and under three APRV experimental conditions. Unit: mL/cmH₂O.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
End-inspiratory esophageal pressure (PesI)
End-inspiratory esophageal pressure (PesI) measured by esophageal manometry, assessed at baseline and under three APRV experimental conditions. Unit: cmH₂O.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
End-expiratory esophageal pressure (PesE)
End-expiratory esophageal pressure (PesE) measured by esophageal manometry, assessed at baseline and under three APRV experimental conditions. Unit: cmH₂O
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Esophageal pressure swing (ΔPes)
Esophageal pressure swing (ΔPes) measured by esophageal manometry, assessed at baseline and under three APRV experimental conditions. Unit: cmH₂O.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
End-inspiratory transpulmonary pressure (PtpI)
End-inspiratory transpulmonary pressure (PtpI) derived from airway and esophageal pressure measurements. Unit: cmH₂O.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Transpulmonary driving pressure (ΔPtp)
Transpulmonary driving pressure (ΔPtp) derived from airway and esophageal pressure measurements. Unit: cmH₂O.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
End-expiratory transpulmonary pressure (PtpE)
End-expiratory transpulmonary pressure (PtpE) derived from airway and esophageal pressure, assessed at baseline and under three APRV experimental conditions. Unit: cmH₂O.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Esophageal pressure-time product per minute (PTPes/min)
Esophageal pressure-time product per minute (PTPes/min) read directly from the ventilator interface. Unit: cmH₂O·s/min.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Dynamic transpulmonary driving pressure (ΔPL,dyn)
Dynamic transpulmonary driving pressure (ΔPL,dyn) obtained from ventilator measurements; only measured in the presence of spontaneous breathing effort. Unit: cmH₂O.
Time frame: At the end of each 30-minute APRV experimental condition (after stabilization)
Inspiratory muscle pressure (Pmus)
Inspiratory muscle pressure (Pmus) obtained from ventilator measurements; only measured in the presence of spontaneous breathing effort. Unit: cmH₂O
Time frame: At the end of each 30-minute APRV experimental condition (after stabilization)
End-expiratory occlusion pressure (ΔPocc)
End-expiratory occlusion pressure (ΔPocc) obtained from ventilator measurements; only measured in the presence of spontaneous breathing effort. Unit: cmH₂O
Time frame: At the end of each 30-minute APRV experimental condition (after stabilization)
Airway occlusion pressure (P0.1)
Airway occlusion pressure (P0.1) obtained from ventilator measurements; only measured in the presence of spontaneous breathing effort. Unit: cmH₂O
Time frame: At the end of each 30-minute APRV experimental condition (after stabilization)
Muscular pressure index (PMI)
Muscular pressure index (PMI) obtained from ventilator measurements; only measured in the presence of spontaneous breathing effort. Unit: cmH₂O
Time frame: At the end of each 30-minute APRV experimental condition (after stabilization)
Negative inspiratory force (NIF)
Negative inspiratory force (NIF) obtained from ventilator measurements; only measured in the presence of spontaneous breathing effort. Unit: cmH₂O
Time frame: At the end of each 30-minute APRV experimental condition (after stabilization)
Heart rate
Heart rate from continuous bedside monitoring, assessed at baseline and under three APRV experimental conditions. Unit: beats per minute.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Mean arterial pressure (MAP)
Mean arterial pressure (MAP) measured via invasive arterial catheter, assessed at baseline and under three APRV experimental conditions. Unit: mmHg.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Vasopressor dosage (μg/kg/min)
Dosage of vasoactive medications, assessed at baseline and under three APRV experimental conditions. Unit: μg/kg/min
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Central venous pressure (CVP)
Central venous pressure (CVP), assessed at baseline and under three APRV experimental conditions. Unit: mmHg.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Right-ventricular fractional area change
Right-ventricular fractional area change measured by transthoracic echocardiography, assessed at baseline and under three APRV experimental conditions. Unit: %.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Velocity-time-integral (VTI)
Velocity-time-integral (VTI) measured by transthoracic echocardiography, assessed at baseline and under three APRV experimental conditions. Unit: cm.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Tricuspid annular plane systolic excursion (TAPSE)
Tricuspid annular plane systolic excursion (TAPSE) measured by transthoracic echocardiography, assessed at baseline and under three APRV experimental conditions. Unit: mm.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Cardiac output (CO)
Cardiac output (CO) calculated from velocity-time integral (VTI) measured by transthoracic echocardiography, assessed at baseline and under three APRV experimental conditions. Unit: L/min.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Stroke volume (SV)
Stroke volume (SV) calculated from velocity-time-integral (VTI) measured by transthoracic echocardiography, assessed at baseline and under three APRV experimental conditions. Unit: mL.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Diaphragm displacement
Diaphragm displacement measured by bedside diaphragm ultrasound, assessed in two out of the three APRV experimental conditions only when spontaneous breathing was present. Unit: mm.
Time frame: At the end of 30-minute APRV experimental conditions with spontaneous breathing effort (after stabilization)
Diaphragm thickening fraction
Diaphragm thickening fraction measured by bedside diaphragm ultrasound, assessed in two out of the three APRV experimental conditions only when spontaneous breathing was present. Unit: %.
Time frame: At the end of 30-minute APRV experimental conditions with spontaneous breathing effort (after stabilization)
Lung 12-zone ultrasound score
Lung ultrasound score based on 12-zone lung ultrasound assessment, assessed at baseline and under three APRV experimental conditions. Unit: unitless.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Overdistension (OD) pixel count
Pixel count of lung overdistension (OD), exported directly from electrical impedance tomography (EIT) software basic module, averaged over complete respiratory cycles within selected time interval, measured at baseline (prior to intervention, after stabilization) and at the end of each 30-minute APRV experimental condition (after stabilization). Unit: pixels.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Overdistension (OD) proportion
Proportion of lung overdistension (OD) relative to total lung-region pixels, exported directly from electrical impedance tomography (EIT) software basic module, averaged over complete respiratory cycles within selected time interval, measured at baseline (prior to intervention, after stabilization) and at the end of each 30-minute APRV experimental condition (after stabilization). Unit: %.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Recruitment (CR) pixel count
Pixel count of lung recruitment (CR), exported directly from electrical impedance tomography (EIT) software basic module, averaged over complete respiratory cycles within selected time interval, measured at baseline (prior to intervention, after stabilization) and at the end of each 30-minute APRV experimental condition (after stabilization). Unit: pixels.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Recruitment (CR) proportion
Proportion of lung recruitment (CR) relative to total lung-region pixels, exported directly from electrical impedance tomography (EIT) software basic module, averaged over complete respiratory cycles within selected time interval, measured at baseline (prior to intervention, after stabilization) and at the end of each 30-minute APRV experimental condition (after stabilization). Unit: %.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Atelectasis (AT) pixel count
Pixel count of lung atelectasis (AT), exported directly from electrical impedance tomography (EIT) software basic module, averaged over complete respiratory cycles within selected time interval, measured at baseline (prior to intervention, after stabilization) and at the end of each 30-minute APRV experimental condition (after stabilization). Unit: pixels.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Atelectasis (AT) proportion
Proportion of lung atelectasis (AT) relative to total lung-region pixels, exported directly from electrical impedance tomography (EIT) software basic module, averaged over complete respiratory cycles within selected time interval, measured at baseline (prior to intervention, after stabilization) and at the end of each 30-minute APRV experimental condition (after stabilization). Unit: %.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Incidence and severity of adverse events
Incidence and severity of adverse events during study interventions, focusing on respiratory events, circulatory events and procedure-related adverse events. Unit: unitless.
Time frame: During each APRV experimental intervention period
Rate of premature intervention discontinuation for safety concerns
Rate of premature discontinuation of study interventions due to safety-related reasons. Unit: %.
Time frame: During each APRV experimental intervention period
Inspired oxygen fraction (FiO₂)
Set inspired oxygen fraction, obtained directly from ventilator readings, recorded at baseline (prior to intervention, after stabilization) and at the end of each 30-minute APRV experimental condition (after stabilization). Unit: %.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Arterial pH
Arterial blood pH measured from arterial blood gas analysis, measured at baseline (prior to intervention, after stabilization) and at the end of each 30-minute APRV experimental condition (after stabilization). Unit: unitless.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Arterial partial pressure of oxygen (PaO₂)
Arterial partial pressure of oxygen measured from arterial blood gas analysis, measured at baseline (prior to intervention, after stabilization) and at the end of each 30-minute APRV experimental condition (after stabilization). Unit: mmHg.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Arterial partial pressure of carbon dioxide (PaCO₂)
Arterial partial pressure of carbon dioxide measured from arterial blood gas analysis, measured at baseline (prior to intervention, after stabilization) and at the end of each 30-minute APRV experimental condition (after stabilization). Unit: mmHg.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Arterial oxygen saturation (SaO₂)
Arterial oxygen saturation measured from arterial blood gas analysis, measured at baseline (prior to intervention, after stabilization) and at the end of each 30-minute APRV experimental condition (after stabilization). Unit: %.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Bicarbonate (HCO₃-)
Serum bicarbonate (HCO₃-) measured from arterial blood gas analysis, measured at baseline (prior to intervention, after stabilization) and at the end of each 30-minute APRV experimental condition (after stabilization). Unit: mmol/L.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Base excess (BE)
Base excess (BE) measured from arterial blood gas analysis, measured at baseline (prior to intervention, after stabilization) and at the end of each 30-minute APRV experimental condition (after stabilization). Unit: mmol/L.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Arterial lactate (Lac)
Arterial lactate (Lac) measured from arterial blood gas analysis, measured at baseline (prior to intervention, after stabilization) and at the end of each 30-minute APRV experimental condition (after stabilization). Unit: mmol/L.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
PaO₂/FiO₂ ratio
PaO₂/FiO₂ ratio calculated from arterial blood gas analysis, measured at baseline (prior to intervention, after stabilization) and at the end of each 30-minute APRV experimental condition (after stabilization). Unit: unitless.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Alveolar-arterial oxygen difference (A-aDO₂)
Alveolar-arterial oxygen difference calculated from arterial blood gas analysis, measured at baseline (prior to intervention, after stabilization) and at the end of each 30-minute APRV experimental condition (after stabilization). Unit: mmHg.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Correlation analysis among multiple respiratory-hemodynamic-diaphragm parameters
Explore the correlations among EIT parameters, respiratory mechanics, blood gas analysis, hemodynamics and diaphragm function across three study conditions.
Time frame: Corresponding study time points
Ventilatory ratio (VR)
Ventilatory ratio (VR), a calculated index reflecting pulmonary dead-space and lung injury severity, is computed from minute ventilation and arterial CO₂ values assessed at baseline and under three APRV experimental conditions. Unit: unitless.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Expired tidal volume (VTe)
Expired tidal volume assessed at baseline and under three APRV experimental conditions. Unit: mL.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Total respiratory rate
Total respiratory rate assessed at baseline and under three APRV experimental conditions. Unit: breaths/min.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Total minute ventilation
Total minute ventilation assessed at baseline and under three APRV experimental conditions. Unit: L/min.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Spontaneous minute ventilation
Spontaneous component of minute ventilation assessed under two APRV experimental conditions only when spontaneous breathing was present, derived directly from ventilator readings. Unit: L/min.
Time frame: At the end of 30-minute APRV experimental conditions with spontaneous breathing effort (after stabilization)
Proportion of spontaneous minute ventilation
Proportion of spontaneous minute ventilation relative to total minute ventilation, calculated under two APRV experimental conditions only when spontaneous breathing was present. Unit: %.
Time frame: At the end of 30-minute APRV experimental conditions with spontaneous breathing effort (after stabilization)
Mechanical power (MP)
Mechanical power of ventilation as an indicator of ventilator-induced lung injury (VILI) risk, obtained directly from ventilator readings at baseline and under three APRV experimental conditions. Unit: J/min.
Time frame: Baseline and at the end of each 30-minute experimental condition during the study intervention period.
Plan to share: No
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Start is estimated for Oct 2026; primary completion for Nov 2026, 1 month later.
Of 264 non-industry interventional studies with no phase under Respiratory Distress Syndrome, half reached primary completion within 24 months of starting (the median), counting those still running; a quarter within 12 and three quarters within 42. This study's planned 1 month is below that.
Counting every sponsor, half of 271 studies reached it within 24 months; a quarter within 12 and three quarters within 42.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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Respiratory Distress Syndrome →
Union Hospital, Tongji Medical College, Huazhong University of Science and Technology →