HFOV is a mechanical ventilation method that pumps small amounts of air into the lungs at a constant high rate. Because the increments of air are small the likelihood of experiencing overdistension and developing VALI may be reduced. While HFOV is an effective, commonly used ventilation method, there have been no studies that demonstrate the efficacy of HFOV in comparison to the efficacy of conventional mechanical ventilation methods. This study will compare two different HFOV techniques: the HFOV-Hi method, which uses higher airway pressure, and the HFOV-Lo method, which uses lower airway pressure. The purpose of this study is to compare the safety and efficacy of HFOV-Hi, HFOV-Lo, and standard mechanical ventilation methods in individuals with ARDS.