High-flow nasal oxygen therapy

Abstract

### Key points High-flow nasal oxygen therapy (HFNOT) is increasingly used as part of both ward-based and critical care management of respiratory failure. Respiratory failure is distressing for patients and treatment modalities currently in use may be associated with discomfort from upper airway drying, tightly fitting facemasks, and resultant complications such as skin breakdown. Invasive ventilation is also associated with a number of complications including ventilator-associated pneumonia. The ability of nasal cannulae to provide positive pressure to the airways was first noted in neonates, and it is in this patient group that this therapeutic effect was first used. A similar continuous positive airway pressure (CPAP) effect, with higher flows, was noted in adults1 and from here, HFNOT was developed.2 HFNOT provides warmed, humidified gases at flows of up to 60 litre min−1, with inspired oxygen concentrations of up to 100%. The use of HFNOT is well validated in neonatal populations and the body of evidence for its use in adults is rapidly growing. There are several different devices available for the provision of high flow, humidified oxygen via nasal cannulae. The devices consist of nasal cannulae with standard sized or wide-bore prongs connected to an oxygen flow meter with an air–oxygen gas blender and gas analyser. They offer maximum gas flow …