New modalities of mechanical ventilation in the adult

Mechanical ventilation is the most important life-saving procedure used for the treatment of acute respiratory failure. A large body of experimental a nd clinical research has been conducted over these last years to better und erstand and improve patient-ventilator interactions and synchrony. In the f ield of the acute respiratory distress syndrome (ARDS), much attention has been paid to the potential harm to the lung generated by high pressure, hig h volume ventilation, as commonly used for ventilating the lungs of these p atients. Because of impressive experimental studies and and of the fear of inducing an excess in mortality because of barotrauma or the so-called "vol utrauma", new targets for alveolar pressure have been defined without payin g too much attention to normalizing alveolar ventilation. Ventilating patie nts with permissive hypercapnia. because of reduced end-inspiratory pressur es and elevated end-expiratory pressure, have been shown to impact on morta lity, although the precise settings and targets are still a matter of debat e among the various clinical trials. This modality have been associated wit h the use of other symptomatic Cools, to reduce hypercapnia, Like dead-spac er washout by tracheal insufflation of gas, or to improve oxygenation, like ventilating the patients in prone position. In the Geld or assisted ventil ation, much knowledge has been gained concerning the determinants of patien t's effort to breathe under partial assisted ventilatory support. Pressure supported ventilation has been used extensively because of its ability to d eliver sufficient peak flow at the early beginning of the breath. A new eme rging modality is called proportional assist ventilation and it drastically differs from all previous modes, in that neither the volume the pressure, or any timing, need to be set on the ventilator. It aims at delivering a su pport directly proportional to the needs of the patient. Lastly, acute deco mpensation of chronic obstructive pulmonary diseases are now treated routin ely without endotracheal intubation, by delivering a ventilatory support th rough a facial or nasal mask. This approach has, allowed to markedly; reduc e the need for: endotracheal intubation, and therefore to reduce complicati ons, length of star and even mortality in this disease.