Validation of the Apnea Test Performed by High-flow Oxygen Therapy in Patients With Clinical Brain Death

NCT ID: NCT05950178

Last Updated: 2024-08-02

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

15 participants

Study Classification

INTERVENTIONAL

Study Start Date

2023-07-10

Study Completion Date

2024-04-07

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

Brain death is a clinical and paraclinical diagnosis established in a known etiological context. It involves the irreversible destruction of cerebral functions in a beating-heart individual.

In the context of organ and tissue donation from a critically ill patient, the clinical diagnosis of brain death is confirmed through a mandatory apnea test. This test is conducted by disconnecting the patient from the ventilator for a duration of 8 to 10 minutes. The test is considered validated when there is no spontaneous respiratory movement and the presence of hypercapnia. Hypercapnia is defined as a PaCO2 (carbon dioxide partial pressure) greater than 60 mmHg or an increase of more than 20 mmHg compared to the pre-ventilator disconnection capnia. These thresholds are meant to provide a strong stimulus to the respiratory centers, objectively confirming the absence of spontaneous ventilation.

In practice, the apnea test is performed under CPAP (Continuous Positive Airway Pressure) or by administering oxygen at 6-10L/min through the endotracheal tube.

High-flow oxygenation could be a simple alternative for the apnea test during the validation of the clinical diagnosis of brain death while reducing the risk of lung derecruitment and compromising organ viability and/or lung donation.

However, due to the high gas flow used (60 L/min), high-flow oxygenation can lead to a "washout" effect in the anatomical dead space, which may lower the carbon dioxide partial pressure. Consequently, even in a patient in a state of brain death, where spontaneous ventilation is absent by definition, it is not certain that the carbon dioxide partial pressure will increase to the threshold of 60 mmHg or more than 20 mmHg in 10 minutes during an apnea test conducted with high-flow oxygenation.

The purpose of this study is, therefore, to examine the feasibility of clinically diagnosing brain death through an apnea test performed with high-flow oxygenation.

To determine whether the validation criterion which involves observing an arterial capnia \> 60 mmHg or an increase \> 20 mmHg (compared to the capnia at the beginning of the test) after 10 minutes can be achieved during an apnea test conducted under high-flow oxygen therapy in patients with clinically confirmed brain death by standard apnea test (under standard oxygen therapy)

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

The protocol is based on performing two consecutive apnea tests on a patient in clinical brain death in intensive care unit. The first apnea test will be conducted under standard oxygen therapy and confirms clinical brain death (standard procedure). The second apnea test (for the study) will be conducted under high-flow oxygen therapy. Only patients whose apnea test is initially validated under standard oxygen therapy will have the second apnea test under high-flow oxygen therapy.

After a standardized preoxygenation, the 1st apnea test will be performed under standard oxygen therapy through the endotracheal tube (flow at 8L/min) for 10 minutes. An arterial blood gas sampling will be sampled every 2 minutes during the1st apnea test.

The confirmation of clinical brain death by validating the apnea test under standard oxygen therapy will be done if the following two conditions are met: 1) absence of a spontaneous respiratory movements AND 2) an arterial capnia \> 60 mmHg or an increase \> 20 mmHg (compared to the capnia at the end of preoxygenation).

Then the patient will be reconnected to the ventilator for 15 minutes. A second standardized preoxygenation will be performed before the 2nd apnea test. The second apnea test will be performed under high-flow oxygen therapy through the endotracheal tube (flow at 50L/min, FiO2 100%) for 10 minutes. An arterial blood gas sampling will be sampled every 2 minutes during the1st apnea test.

Then the patient will be reconnected to the ventilator with the same settings before the start of the study.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Brain Death

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

NA

Intervention Model

SINGLE_GROUP

Non-randomized controlled single-center trial.
Primary Study Purpose

DIAGNOSTIC

Blinding Strategy

NONE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Clinical brain death

The protocol is based on performing two consecutive apnea tests on a patient in clinical brain death in intensive care unit. The first apnea test will be conducted under standard oxygen therapy and confirms clinical brain death (standard procedure). The second apnea test (for the study) will be conducted under high-flow oxygen therapy. Only patients whose apnea test is initially validated under standard oxygen therapy will have the second apnea test under high-flow oxygen therapy.

Group Type OTHER

Apnea test under high-flow oxygenation

Intervention Type DIAGNOSTIC_TEST

Apnea test under high-flow oxygenation in patients with a confirmed clinical brain death by a standard apnea test (under standard oxygen therapy)

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

Apnea test under high-flow oxygenation

Apnea test under high-flow oxygenation in patients with a confirmed clinical brain death by a standard apnea test (under standard oxygen therapy)

Intervention Type DIAGNOSTIC_TEST

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

* All patients in critical care with clinical brain death and potential organ and tissue donors for whom an apnea test is indicated.

Exclusion Criteria

* Minor patients.
* Person under guardianship
* Protected Majors
* Not affiliated to French social security
* Pregnant women.
* Patients with a history of Chronic Obstructive Pulmonary Disease with a GOLD score of III or IV.
* Patients with at least one absolute contraindication to organ donation.
* Patients whose relatives have spontaneously expressed the patient's refusal to donate organs for therapeutic purposes.
* Patients on VA ECMO and, in general, any patient with a contraindication to performing the apnea test (DV, significant hemodynamic instability...).
* Patients whose relatives have refused the patient's participation in the study.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

Centre Hospitalier Régional d'Orléans

OTHER

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

Responsibility Role SPONSOR

Principal Investigators

Learn about the lead researchers overseeing the trial and their institutional affiliations.

Damien BARRIER

Role: PRINCIPAL_INVESTIGATOR

CHR d'Orléans

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

CHR d'ORLEANS

Orléans, , France

Site Status

Countries

Review the countries where the study has at least one active or historical site.

France

References

Explore related publications, articles, or registry entries linked to this study.

Greer DM, Shemie SD, Lewis A, Torrance S, Varelas P, Goldenberg FD, Bernat JL, Souter M, Topcuoglu MA, Alexandrov AW, Baldisseri M, Bleck T, Citerio G, Dawson R, Hoppe A, Jacobe S, Manara A, Nakagawa TA, Pope TM, Silvester W, Thomson D, Al Rahma H, Badenes R, Baker AJ, Cerny V, Chang C, Chang TR, Gnedovskaya E, Han MK, Honeybul S, Jimenez E, Kuroda Y, Liu G, Mallick UK, Marquevich V, Mejia-Mantilla J, Piradov M, Quayyum S, Shrestha GS, Su YY, Timmons SD, Teitelbaum J, Videtta W, Zirpe K, Sung G. Determination of Brain Death/Death by Neurologic Criteria: The World Brain Death Project. JAMA. 2020 Sep 15;324(11):1078-1097. doi: 10.1001/jama.2020.11586.

Reference Type BACKGROUND
PMID: 32761206 (View on PubMed)

Levesque S, Lessard MR, Nicole PC, Langevin S, LeBlanc F, Lauzier F, Brochu JG. Efficacy of a T-piece system and a continuous positive airway pressure system for apnea testing in the diagnosis of brain death. Crit Care Med. 2006 Aug;34(8):2213-6. doi: 10.1097/01.CCM.0000215114.46127.DA.

Reference Type BACKGROUND
PMID: 16540953 (View on PubMed)

Lyons C, Callaghan M. Apnoeic oxygenation with high-flow nasal oxygen for laryngeal surgery: a case series. Anaesthesia. 2017 Nov;72(11):1379-1387. doi: 10.1111/anae.14036.

Reference Type BACKGROUND
PMID: 29047136 (View on PubMed)

Fossat G, Nay MA, Jacquier S, Desmalles E, Boulain T. High-flow oxygen during spontaneous breathing trial for patients at high risk of weaning failure. Intensive Care Med. 2021 Aug;47(8):916-917. doi: 10.1007/s00134-021-06450-x. Epub 2021 Jun 14. No abstract available.

Reference Type BACKGROUND
PMID: 34128122 (View on PubMed)

Vogelmeier CF, Criner GJ, Martinez FJ, Anzueto A, Barnes PJ, Bourbeau J, Celli BR, Chen R, Decramer M, Fabbri LM, Frith P, Halpin DM, Lopez Varela MV, Nishimura M, Roche N, Rodriguez-Roisin R, Sin DD, Singh D, Stockley R, Vestbo J, Wedzicha JA, Agusti A. Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease 2017 Report. GOLD Executive Summary. Am J Respir Crit Care Med. 2017 Mar 1;195(5):557-582. doi: 10.1164/rccm.201701-0218PP.

Reference Type BACKGROUND
PMID: 28128970 (View on PubMed)

Wijdicks EF, Manno EM, Holets SR. Ventilator self-cycling may falsely suggest patient effort during brain death determination. Neurology. 2005 Sep 13;65(5):774. doi: 10.1212/01.wnl.0000174626.94197.62. No abstract available.

Reference Type BACKGROUND
PMID: 16157923 (View on PubMed)

Shapiro BA. The apnea-PaCO2 relationship: some clinical and medico-legal considerations. J Clin Anesth. 1989;1(5):323-7. doi: 10.1016/0952-8180(89)90069-x. No abstract available.

Reference Type BACKGROUND
PMID: 2516731 (View on PubMed)

Birks EJ, Burton PB, Owen VJ, Latif N, Nyawo B, Yacoub MH. Molecular and cellular mechanisms of donor heart dysfunction. Transplant Proc. 2001 Aug;33(5):2749-51. doi: 10.1016/s0041-1345(01)02178-9. No abstract available.

Reference Type BACKGROUND
PMID: 11498147 (View on PubMed)

Barrier D, Vanacker L, Muller G, Szychowiak P, Bretagnol A, Levebvre I, Narcisse E, Pascot L, Boulain T, Nay MA. Feasibility of High-Flow Oxygen Therapy in Apnea Testing for Brain Death Diagnosis. Crit Care Med. 2025 Jul 1;53(7):e1449-e1456. doi: 10.1097/CCM.0000000000006717. Epub 2025 May 19.

Reference Type DERIVED
PMID: 40387463 (View on PubMed)

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

CHRO-2022-10

Identifier Type: -

Identifier Source: org_study_id

More Related Trials

Additional clinical trials that may be relevant based on similarity analysis.

Cardiac Arrest Bundle of CARE Trial
NCT05917717 RECRUITING NA