Non-invasive oxygenation strategies include standard oxygen therapy, non-invasive ventilation, and high-flow nasal oxygen. Non-invasive ventilation in turn may be delivered via a helmet or a face-mask interface. When deployed for the treatment of acute hypoxemic respiratory failure, on average, all these strategies reduce the risk of intubation and may reduce the risk of all-cause mortality. In addition, when used upon extubation, they appear to reduce the risk of re-intubation in adult critically ill patients. In this setting, it may be especially useful to use both high flow nasal oxygen and non-invasive ventilation. This talk will not describe the use of non-invasive ventilation for classic indications such as acute exacerbation of chronic obstructive pulmonary disease or congestive heart failure.