[The hypotensive pneumothorax syndrome].

In the light of a further case of hypotensive pneumothorax, an account is given of the physiopathology of the syndrome with special reference to the importance of endothoracic pressure imbalance as a cause of functional insufficiency of the lung on the healthy side. Support is given to the therapeutic principles, i.e. emergency normalisation of pressure values in the pleural cavity on the impaired side, and resolutive toilet of tracheobronchial trunk.