Thirteen studies (n=19,676) were included in the review. Four studies (n=19,188) were retrospective or observational studies. Nine studies (n=488) were prospective RCTs.
RCTs (nine RCTs). Two RCTs reported that lung-protective mechanical ventilation with lower tidal volumes was associated with a shorter duration of intubation, a lower incidence of pulmonary infection or a reduction of postoperative mechanical ventilation for patients without ALI/ARDS compared to controls with larger tidal volumes. Four RCTs reported the harmful effects of mechanical ventilation with large tidal volumes in patients without ALI/ARDS, but three RCTs did not show any effect of the use of large tidal volumes on ventilator-associated lung injury. Most of the RCT differences were in biochemical surrogate outcomes.
Retrospective/observational studies (four studies). Three studies showed that the development of ALI/ARDS was associated with mechanical ventilation using large tidal volumes for longer than 12 hours in patients without ALI/ARDS at the onset of ventilation. One study suggested similar harmful effects of the use of large tidal volumes for several hours ventilation in patients without ALI/ARDS.