Question
What is high flow oxygen?
Answer
- High flow oxygen systems include those that can supply a flow that meets or exceed the patient’s peak inspiratory flow.
- These systems use air-entrainment or blending systems to create precise Fi02.
For oxygen devices, there are high-flow, low-flow, and reservoir systems. Many times, the terms high-flow and high liter flow all get mixed. When by definition, they are quite different. A high-flow oxygen therapy system includes those that supply a flow that meets or exceeds the patient's inspiratory flow demand. Many of these terms are used synonymously when they are very different. You might have learned the magic box or some other formula to calculate the total flow of an oxygen device. When we are talking about total flow, that is how we get a true high-flow device.
Although they can get to higher liter flows, traditional oxygen delivery devices are often diluted by room air, so the patient is breathing oxygen and room air. The FiO2 then becomes variable. These devices cannot meet the definition of true high-flow because they do not bring any additional flow from another source to increase the total flow of the device. Systems that do meet this are high-flow air entrainment and blending systems. An entrainment system, for example, would be a venturi mask. A blending system would be just like it sounds-- a machine that has a blender built inside of it so it can create a precise FiO2.
This Ask the Expert is an edited excerpt from the course, High Flow Nasal Oxygen: What’s What!, presented by Jessica Fino, EdD, RRT.
