Although studies have started to investigate the efficacy of DAO in preventing desaturation during RSI, evidence is still lacking in the emergency department patient population. The primary question being asked is: does diffuse apneic oxygenation increase the average lowest arterial oxygen saturation during rapid sequence intubation when compared to usual care? Secondary question being asked is: does diffuse apneic oxygenation decrease the incidence of desaturation in general, as well as hypoxemia and severe hypoxemia? The third question being asked is: does diffuse apneic oxygenation increase the time to desaturation?