COMPARISON OF LUNG RECRUITABILITY ASSESSMENT BY HYSTERESIS RATIO AND RECRUITMENT-TO-INFLATION RAT… (NCT07713420) | Clinical Trial Compass
Not Yet RecruitingNot Applicable
COMPARISON OF LUNG RECRUITABILITY ASSESSMENT BY HYSTERESIS RATIO AND RECRUITMENT-TO-INFLATION RATIO, AND PEEP TITRATION IN ARDS.
30 participantsStarted 2026-07
Plain-language summary
This multicenter, single-blind physiological study aims to compare two bedside methods for assessing lung recruitability in mechanically ventilated patients with acute respiratory distress syndrome (ARDS): the recruitment-to-inflation (R/I) ratio and the pressure-volume (PV) loop hysteresis ratio. Lung recruitability will be defined according to the reduction in lung collapse measured by electrical impedance tomography (EIT) during a standardized lung recruitment maneuver.
Following baseline measurements, participants will undergo sequential physiological assessments, including lung recruitability evaluation using both the R/I ratio and a low-flow PV loop, a standardized lung recruitment maneuver with a decremental PEEP trial, and a second PV loop performed at a lower maximum inflation pressure. The order of the R/I ratio assessment and the PV loop maneuver will be randomized.
In a final crossover phase, four different PEEP titration strategies will be evaluated in randomized order. Each strategy will be applied for 15 minutes and separated by a washout period at the patient's baseline clinical PEEP. Respiratory mechanics, gas exchange, ventilation/perfusion distribution, and hemodynamic variables will be assessed throughout the protocol.
The primary objective is to determine the agreement between the hysteresis ratio and the R/I ratio for identifying lung recruitability. Secondary objectives include evaluating whether a PV loop performed with a lower maximum pressure provides similar information on recruitability and comparing the physiological effects of different PEEP titration strategies. Approximately 30 patients with moderate-to-severe ARDS receiving invasive mechanical ventilation will be enrolled.
Who can participate
Age range
18 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* Intubated patients with acute respiratory distress syndrome (ARDS): PaO2/FiO2 ratio \<200, with bilateral infiltrates of non-cardiogenic origin, with a PEEP of at least 5 cmH2O.
* The patient is receiving mechanical ventilation and continuous sedation.
* The patient has an esophageal balloon.
* Written informed consent signed and dated by the patient or one relative in case the patient is unable to consent, after a full explanation of the study by the investigator and prior to study participation
Exclusion Criteria:
* Patients with\< 18 years old
* Pregnant woman
* Lung recruitment maneuvers are deemed unsafe by the medical team
* Unable to fit EIT belt due to patient size
* Contraindications to EIT monitoring (e.g. burns, pacemaker, thoracic wounds limiting electrode placement)
* Hemodynamic instability (Systolic BP \< 75 mmHg or MAP \< 60 mmHg despite vasopressors and/or heart rate \< 55 bpm)
* Hypernatremia (Na+ \>145mEq/L)
* The formalized ethical decision to withhold or withdraw life support
* Patient under guardianship
* Patients deprived of liberties
* Impossibility to give informed consent by both patient and family (i.e. language barrier)
* Patient was already enrolled in the present study in a previous episode of acute respiratory failure.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Agreement between the hysteresis ratio and the recruitment-to-inflation (R/I) ratio for assessing lung recruitability
Timeframe: During the study procedure (approximately within 2-3 hours after enrollment).