Effect of Ventilation Mode in the Pupillary Light Reflex: A Crossover Study (NCT07082569) | Clinical Trial Compass
Not Yet RecruitingNot Applicable
Effect of Ventilation Mode in the Pupillary Light Reflex: A Crossover Study
Greece36 participantsStarted 2025-07-15
Plain-language summary
The goal of this clinical trial is to explore whether different modes of mechanical ventilation affect pupillary constriction velocities in critically ill patients without brain injury. The study aims to determine whether the type of mechanical ventilation (volume control, pressure control, or pressure-regulated volume control) influences the maximum and mean constriction velocity measured by automated pupillometry. The trial also investigates whether changes in pupil dynamics reflect subtle alterations in brainstem-autonomic interaction induced by ventilation mode.
The comparison involves volume control, pressure control, and pressure-regulated volume control in a randomized crossover design to assess whether ventilation mode has a measurable effect on pupil response.
Eligible participants will be intubated ICU patients receiving assist control ventilation who are not yet ready for spontaneous breathing trials. Serial pupillometry measurements will be conducted while participants are ventilated with each mode for at least 15 minutes. Sedation and lighting conditions will remain consistent throughout the protocol. Participants with acute or chronic neurologic conditions or ventilator dyssynchrony will be excluded.
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
* Adult patients (≥18 years old)
* Receiving positive-pressure mechanical ventilation
* Under light or no sedation (e.g., RASS score between -2 and 0)
* Clinically assessed by the treating physician as not yet ready for weaning from mechanical ventilation
* Hemodynamically stable at the time of measurement
* Presence of an arterial catheter in place for blood gas analysis
* Written informed consent obtained from the patient's legal representative Exclusion Criteria
* Acute or chronic neurological disease affecting brainstem function or pupillary responses
* Dyssynchrony with the ventilator or need for high ventilatory support adjustments
* Facial injuries, edema, or conditions precluding accurate pupillometry
* Use of neuromuscular blocking agents within the prior 6 hours
* Severe metabolic or acid-base imbalances that may influence autonomic regulation
* Concurrent participation in another interventional study that could affect neurological or autonomic outcomes
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
Maximum Pupillary Constriction Velocity
Timeframe: At 30 minutes after each ventilation mode initiation (VC, PC, PRVC).