Toward a better ventilation strategy for patients with acute lung injury

Ventilator-induced lung injury is a major outcome determinant of the acute respiratory distress syndrome (ARDS). Ventilatory strategies that limit ventilator-induced lung injury should improve outcome from ARDS. The ARDSnet trial showed improved survival in subjects ventilated with a lower tidal volume. Although this trial developed and tested a rigorous clinical protocol, it did not define the limits to which tidal volume reduction would benefit outcome. It is also not at all clear if it is the reduction in tidal volume or the reduction in plateau airway pressure that confers this benefit. Finally, ventilator-induced lung injury occurs more commonly from repetitive collapse and re-expansion of injured lung units rather than from the overdistention of persistently aerated lung units. This was not addressed in the trial design. Thus, further study using targeted open-lung strategies are also needed.