['The purpose of the ventilatory management of acute respiratory distress syndrome (ARDS) is to avoid any barotrauma to the lungs by decreasing the tidal volume at the expense of permissive hypercapnia. This hypercapnia is extremely dangerous for severe head trauma patients because it increases intracranial pressure. The solution could be the use of tracheal gas which insufflation (TGI) allows the reduction of arterial carbon dioxide tension (PaCO(2)) while controlling airway pressures.', "We report the cases of two patients with ARDS and severe head trauma. The decrease of tidal volume ( by 60 and 25% respectively) in association with tracheal gas insufflation allowed to reduce plateau airway pressure (<35 cm d'H(2)O) and PaCO(2) (in the first case by 23% and in the second case, by 11% for the second hour then by 24%), while intracranial pressure remained constant or was lowered (in the second case by 39% for the second hour). TGI consisted in insufflating fresh gas via a small catheter placed in the trachea (0(2) at 6 L*min(-1) in the first patient and 4 L*min(-1) in the second case)."] Does [ Tracheal gas insufflation avoid hypercapnia in patients with severe head trauma and acute lung injury ]?