High flow nasal oxygen therapy in adult anaesthesia

High flow nasal oxygen (flow rates of 20-70 L/min) is a relatively new addition to the therapeutic armamentarium of the modern physician. It consists of warmed, humidified mixture of oxygen and air that is delivered at flow rates of typically 20-70 L/min via purpose-built nasal cannulae. This review will focus on important implications of high flow nasal oxygen therapy in adult anaesthesia. We review the development history and current evidence of physiological benefits which are described, as well as recent developments in its uses for adult anaesthesia, including pre-oxygenation and intubation, post-extubation and procedural oxygenation. With new applications for this technology being regularly discovered, it is quickly becoming an essential piece of equipment in modern anaesthetic practice.