Sudden death in ambulatory is a major public health issue: only few survivors, severe brain damage, high socio-economic cost. To improve survival and neurological recovery of these patients, an early therapeutic moderate hypothermia could be promising, as strongly suggested by previous preclinical studies on small animals through hypothermic total liquid ventilation (TLV) with perfluorocarbons (PFC) that maintain normal gas exchanges, and where lungs act as a heat exchanger (INSERM U955-E3, partner and pioneer of this project).

Before translation of hypothermic TLV to humans, studies on large animals are necessary. The project ABYSS concerns the development and validation of a total liquid ventilator prototype suitable for large animals (no suitable devices exist on the market). ABYSS involves a consortium of 4 partners: an industrial company (Bertin Technologies) and three academic laboratories (INSERM U955-E3, INSERM U955-E13 and IR4M CNRS UMR8081).

The study, which lasted three years, has led to: 1) Realize a prototype of total liquid ventilator for ventilating and cooling large animals, 2) Study the cooling on large animals with TLV, both on beating heart and under external cardiac massage, 3) Study another therapeutic indication: organ preservation of dead patients, 4) Compare three PFC already used as medical devices and analyze the impact of using PFCs with quite unusual physical properties on respiratory flows and airway resistance, 5) Study the miniaturization of the ventilator to enable its use in mobile intensive care unit.

The next task will be to improve the understanding of the broncho-alveolar response (at various scales from organ to pulmonary cells) under total liquid ventilation on large animals, in order to get knowledge to improve and to optimize the tolerance of the respiratory system to liquid ventilation with PFC.