Not Yet RecruitingNot Applicable

Efficacy of High-Flow Humidified Oxygen (HFHO) in Apneic Oxygenation for Apnea Testing: A Comparison With Continuous Positive Airway Pressure (CPAP)

France28 participantsStarted 2026-09-15

Plain-language summary

Brain death (BD) is characterized by a severe brain injury resulting in irreversible loss of all brain and brainstem functions, while other organs may remain viable. The diagnosis of BD is based on the presence of coma, absence of brainstem reflexes, and absence of spontaneous breathing confirmed by an apnea test. In France, the apnea test is mandatory prior to organ procurement. The apnea test aims to demonstrate that hypercapnia, a strong ventilatory stimulus, does not induce any respiratory movements. In current practice, the apnea test is performed by disconnecting the patient from mechanical ventilation for 8-10 minutes while administering oxygen. Oxygenation strategies during apnea vary across French centers. Although the use of continuous positive airway pressure (CPAP) is recommended, a substantial proportion of tests are still performed without positive end-expiratory pressure (PEEP) effect, using either an open T-piece or an intratracheal oxygen catheter. These methods are associated with a higher risk of complications, such as hypoxemia, and potential adverse effects on organ function, which is particularly relevant in the context of organ donation. Humidified high-flow oxygen (HHFO), delivered via a specialized device connected to the endotracheal tube, provides high flow rates (up to 60 L/min), allows precise adjustment of the fraction of inspired oxygen (FiO₂ up to 1.0), and generates a minimal PEEP effect. HHFO is routinely used in intensive care units. While its feasibility during apnea testing has been reported, its efficacy during BD diagnosis has not been well evaluated. Preliminary observations in intensive care patients with clinical brain death suggest that HHFO can be safely used during the apnea test, allowing achievement of hypercapnia and confirmation of absence of spontaneous respiration while maintaining better oxygenation compared with conventional oxygen delivery via an open T-piece. This study aims to evaluate the efficacy of HHFO for apneic oxygenation during the apnea test, in comparison with the recommended method using CPAP.

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 intensive care unit patients * fulfilling all criteria for clinical brain death, for whom confirmation of the absence of spontaneous breathing requires performance of an apnea test * And for whom consent to participate in the study was sought from a trusted person or a family member Exclusion Criteria: * History of chronic obstructive pulmonary disease (COPD) classified as GOLD stage III or IV. * Current extracorporeal life support, including veno-arterial (VA) or veno-venous (VV) extracorporeal membrane oxygenation (ECMO). * PaO₂/FiO₂ ratio ≤ 150 on the most recent arterial blood gas analysis, obtained within 24 hours prior to the screening visit. * Presence of at least one clear or absolute contraindication to the procurement of at least one organ. * Presence of a high cervical spinal cord injury. * Patient in the prone position and/or with a contraindication to placement in the supine position at 30°. * Minor patient. * Protected adult under legal guardianship or curatorship. * Individual under judicial protection (safeguard of justice). * Individuals deprived of liberty. * Individual not covered by a social security or health insurance system. * Pregnant or breastfeeding woman.

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.

1This trial is studying apnea testing for brain death — can you explain what an apnea test is and why it would be relevant to my or my loved one's situation right now?
2Since this trial compares two methods of delivering oxygen during the apnea test — high-flow humidified oxygen and CPAP — can you walk me through how each method works and whether one might be safer or more appropriate given the patient's current condition?
3The trial is listed as 'not yet recruiting,' which means it isn't open yet — are there other centers already doing this comparison, or is the standard apnea test method what would be used right now?
4The primary outcome is measuring oxygen levels in the blood at the beginning and end of the apnea test — can you explain what those oxygen changes mean clinically, and how they affect the conclusions drawn from the test?
5Since this is a Phase NA study focused on a diagnostic procedure rather than a treatment, what would participation actually involve for the patient, and does it change how the brain death evaluation is conducted in any meaningful way?

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

Change in PaO₂ (mmHg) between the beginning and the end of an apnea test under HHFO and CPAP

Timeframe: From ventilator disconnection to 10th minute of the apnea test

Trial details

NCT IDNCT07640009

SponsorCentre Hospitalier Régional d'Orléans

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2028-09-15

View on ClinicalTrials.gov More Death, Brain trials