Death, Brain

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.

APICES trial is an investigator-initiated, multicenter, multicenter, randomized, double-blind, placebo-controlled clinical trial that plans to enroll 396 patients with a 1-year follow-up, including a neurovascular imaging examination \[digital subtraction angiography (DSA), CT angiography (CTA) or magnetic resonance angiography (MRA)\] at 6 months after index treatment. It was designed in compliance with the Declaration of Helsinki and the International Conference on Harmonization Good Clinical Practice guidelines. The study was approved by the Ethics Committee of Zhujiang Hospital of South Medical University (2024-KY-032-02) and registered at ClinicalTrials.gov (NCT06308952). The participants will be recruited from twelve advanced stroke centers in China.

Solid organ transplantation is the treatment of choice for end stage organ failure to improve patients' quality of life and survival. Each year, more than 5,000 solid organ transplants are performed in France, mainly from brain death donors (BDD). Approximately 1,500 BDD donors have one or more organs removed each year. Despite the growing demand for transplanted organs, the number of organs available from deceased donors has remained stable over the past few decades. This highlights the need to optimize the management of potential BDD, in order to increase both the quality and number of transplanted organs. Several studies have found an association between the characteristics and management of BDD donors and the number of organs, or even the function of transplanted organs. Data suggest that hemodynamic, respiratory, and metabolic therapeutic targets during BDD management prior to multi-organ procurement were associated with a higher number of transplanted organs compared to standard care. However, this has never been confirmed in a French population. Furthermore, while the impact of these therapeutic goals has been studied after the donor is in a state of brain death, the events occurring in the ICU before reaching brain death status and their impact on the number of organs retrieved have not been investigated. Lastly, the intensity of the therapeutic interventions used to achieve these goals, and certain management delays, have only been partially studied. Our hypothesis is that achieving a bundle of therapeutic goals, and the intensity of the interventions used to reach these goals, both before and after BDD, are associated with a greater number of organs retrieved.