Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome.

Background: Traditional approaches to mechanical ventilation use tidal volu mes of 10 to 15 ml per kilogram of body weight and may cause stretch-induce d lung injury in patients with acute lung injury and the acute respiratory distress syndrome. We therefore conducted a trial to determine whether vent ilation with lower tidal volumes would improve the clinical outcomes in the se patients. Methods: Patients with acute lung injury and the acute respiratory distress syndrome were enrolled in a multicenter, randomized trial. The trial compa red traditional ventilation treatment, which involved an initial tidal volu me of 12 ml per kilogram of predicted body weight and an airway pressure me asured after a 0.5-second pause at the end of inspiration (plateau pressure ) of 50 cm of water or less, with ventilation with a lower tidal volume, wh ich involved an initial tidal volume of 6 ml per kilogram of predicted body weight and a plateau pressure of 30 cm of water or less. The first primary outcome was death before a patient was discharged home and was breathing w ithout assistance. The second primary outcome was the number of days withou t ventilator use from day 1 to day 28. Results: The trial was stopped after the enrollment of 861 patients because mortality was lower in the group treated with lower tidal volumes than in the group treated with traditional tidal volumes (31.0 percent vs. 39.8 per cent, P=0.007), and the number of days without ventilator use during the fi rst 28 days after randomization was greater in this group (mean [+/-SD], 12 +/-11 vs. 10+/-11; P=0.007). The mean tidal volumes on days 1 to 3 were 6.2 +/-0.8 and 11.8+/-0.8 ml per kilogram of predicted body weight (P<0.001), r espectively, and the mean plateau pressures were 25+/-6 and 33+/-8 cm of wa ter (P<0.001), respectively. Conclusions: In patients with acute lung injury and the acute respiratory d istress syndrome, mechanical ventilation with a lower tidal volume than is traditionally used results in decreased mortality and increases the number of days without ventilator use. (N Engl J Med 2000;342:1301-8.) (C) 2000, M assachusetts Medical Society.