[Respiratory physiology during water immersion (author's transl)].

In this review, the author recalls the essential modifications induced by water immersion up to the neck. The ventilatory mechanics show an important decrease of end expiratory level being able to bring a ventilation in closing volume. We notice an increase of cardiac output, of pulmonary artery pressure and central blood volume. After the age of 25, we notice an hypoxia likely due to ventilation at closing volume level.