Up until recently, a tight-fitting mask was one of the only ways to deliver non-invasive positive-pressure ventilation.
High-flow nasal cannulas (HFNC) have been adapted from use in neonates to adults to deliver continuous positive airway pressure (CPAP).
HFNC provides continuous, high-flow (up to 60 liters), and humidified-oxygen via nasal cannula providing positive pressure to the pharynx and hypopharynx. Patients tolerate it well and it is less claustrophobic than tight-fitting masks.
HFNC does not generate the same amount of pressure as CPAP so it may be best utilized as an intermediate step between low-flow oxygen (i.e., traditional nasal cannula) and non-invasive positive pressure ventilation with tight-fitting masks.
Check with your respiratory department if these devices are locally available.
Kernick, j. What is the evidence for the use of high flow nasal cannula oxygen in adult patients admitted to critical care units? A systematic review. Aust Crit Care. 2010 May;23(2):53-70. Epub 2010 Mar 5.
Parke, R. A preliminary randomized controlled trial to assess effectiveness of nasal high-flow oxygen in intensive care patients. Respir Care. 2011 Mar;56(3):265-70. Epub 2011 Jan 21.