A Fresh Look at the Physiologic Effects of High-Flow Nasal Cannulae and the Role They Play in Patient Care

Treatment strategies to address oxygenation prob-lems in critically ill patients with hypoxemic respira-tory failure commonly fall into 3 categories: use of simple oxygen equipment, use of noninvasive ventila-tion, or use of invasive ventilation. These categories typically represent a stepwise approach to the man-agement of patients with increased levels of oxygen demands. High-flow nasal cannula (HFNC), nasal high-flow oxygen therapy, and high-flow therapy are terms used to describe flows of 6 L/min delivered through nasal cannula. Most often these high flows are delivered through an air/oxygen blender and heated humidifier. What makes this therapy unique is that it not only pro-vides oxygen therapy similar to other simple oxyge