The overall objective of this study is to determine if Vapotherm high flow nasal cannula therapy (HFT), when used to treat respiratory failure in the ED, is at least equivalent to the current standard of care for non-invasive ventilatory support, non-invasive positive pressure mask ventilation (NIPPV). Moreover, this study will investigate the potential that HFT has possible advantages over NIPPV, such as decreased time to patient stability from respiratory failure, and the ease of use as a first line intervention for respiratory failure in the ED environment.