Lung-Protective ventilation for all? (Cardiogenic oedema, pulmonary embolism, asthma, COPD)

Mechanical ventilation is an essential support in critical care; its modalities can modify the evolution of the patient. Animal and clinical studies during acute respiratory distress syndrome (ARDS) have shown the deleterious role of tidal volume (Vt) >= 12 mL/kg ideal body weight (IBW). These works have led to the concept of ventilator-induced lung injury (VILI) whose main determinants are volotrauma, barotrauma and atelectrauma. It seems that the adequacy between administered Vt and available pulmonary volume monitored by the driving pressure is an essential determinant of VILI. These mechanisms of lung injury are additive and can be considered as a mechanical energy delivered to the lung. During ARDS, protective ventilation using Vt of 6 mL/kg IBW and positive expiratory pressure (PEEP) was evaluated. The positive results of these studies led to extrapolate this concept to anaesthesia and to all critical patients without ARDS criteria receiving ventilation. Cohort studies conducted in patients without ARDS suggest that a Vt decrease combined with protective ventilation strategies are associated with a lower incidence of ARDS and in some studies with improved prognosis. However, the results of several randomised trials underway will make progress on the modalities of this protective ventilation applied to all ventilated patients. Protective ventilation seems to be preferred but need to be integrated into the global management of the pathology concerned.