A 55-year-old man is hospitalized with severe community-acquired pneumonia, and the acute respiratory distress syndrome (ARDS) develops. The patient requires intubation and mechanical ventilation. An intensive care specialist recommends the use of a low-tidal-volume ventilation strategy, which may reduce the risk of ventilator-induced lung injury and is associated with better survival in patients with ARDS than conventional ventilation. A 55-year-old man is hospitalized with severe community-acquired pneumonia, and the acute respiratory distress syndrome develops. A low-tidal-volume ventilation strategy may reduce the risk of ventilator-induced lung injury and is associated with better survival than conventional ventilation. Foreword This Journal feature begins with a case vignette that includes a therapeutic recommendation. A discussion of the clinical problem and the mechanism of benefit of this form of therapy follows. Major clinical studies, the clinical use of this therapy, and potential adverse effects are reviewed. Relevant formal guidelines, if they exist, are presented. The article ends with the author's clinical recommendations. Stage A 55-year-old man who is 178 cm tall and weighs 95 kg is hospitalized with community-acquired pneumonia and progressively severe dyspnea. His arterial oxygen saturation while breathing 100% oxygen through a face mask is 76%; a chest radiograph shows diffuse alveolar infiltrates with air bronchograms. He is intubated and receives mechanical ventilation; ventilator settings include a tidal volume of 1000 ml, a positive end-expiratory pressure (PEEP) of 5 cm of water, and a fraction of inspired oxygen (FIO 2 ) of 0.8. With these settings, peak airway pressure is 50 to 60 cm of water, plateau airway pressure is . . .