In November 1999, the Network began a new trial as a follow-on to the ventilator trial that has been named the "Assessment of Low Tidal Volume and Elevated End-Expiratory Pressure to Obviate Lung Injury" (ALVEOLI). This trial was a prospective, randomized, controlled multicenter trial that included 549 patients and compared two groups of patients. Patients were randomized to receive mechanical ventilation with either lower or higher PEEP, which were set according to different tables of predetermined combinations of PEEP and fraction of inspired oxygen. The primary end point was mortality at 60 days. Secondary endpoints included ventilator-free days and organ failure-free days. The trial has ended and results were published in the July 22, 2004, issue of the New England Journal of Medicine. The results suggest that in patients with acute lung injury and ARDS who receive mechanical ventilation with a tidal-volume goal of 6 ml per kilogram of predicted body weight and an end-inspiratory plateau-pressure limit of 30 centimeters of water, clinical outcomes are similar whether lower or higher PEEP levels are used.