High-Flow Nasal Oxygen Safety and Efficacy

Guideline Recommendations

The British Thoracic Society recommends oxygen delivery at ≥2 L/min via nasal cannulae during endoscopy to maintain SpO2 >90%, but emphasizes oxygen should only be given to correct hypoxemia, not routinely, particularly in patients at risk of hypercapnia 1, 2
The American Gastroenterological Association notes that while supplemental oxygen reduces desaturation magnitude, there is "little evidence that this practice reduces significant cardiopulmonary complications" and warns that oxygen may delay recognition of apnea and respiratory failure 3, 4
The Difficult Airway Society recommends HFNO as the technique of choice for procedural oxygenation when available, noting reported desaturation rates of 12-16% with low-flow oxygen versus 0-1.5% with HFNO 5

For patients at risk of hypercapnia, exercise caution with any supplemental oxygen, target lower SpO2 88-92%, and consider transcutaneous CO2 monitoring 1, 2
Continuous pulse oximetry is mandatory regardless of oxygen delivery method, and oxygen may delay recognition of hypoventilation, so clinical assessment and consideration of capnography remain essential 1, 2, 3

The use of HFNO provides multiple mechanisms that explain its superior safety profile, including delivering warm, humidified oxygen, providing modest positive end-expiratory pressure, reducing anatomical dead space, and improving pulmonary compliance, with better patient comfort compared to masks 5

High-flow nasal oxygen delivers warm and humidified oxygen at high flow rates (up to 60 L/min), provides modest positive end-expiratory pressure, improves pulmonary compliance, reduces anatomical dead space through washout effect, and reduces work of breathing during the procedure, as noted by the American Thoracic Society 6

High-flow nasal oxygen reduces patient discomfort compared to other oxygen delivery methods, as recommended by the European Respiratory Society 7

The use of high-flow nasal oxygen can be cost-effective, as it may reduce procedural complications and interruptions, thereby offsetting the higher initial costs of the equipment, according to the European Respiratory Society 8

High-flow nasal oxygen may require additional equipment and training compared to conventional oxygen therapy, and there is limited evidence specifically for certain types of endoscopic procedures, as noted by the American College of Physicians 9
The use of high-flow nasal oxygen may increase ICU length of stay in some contexts, though this is likely due to institutional policies rather than clinical necessity, as reported by the European Respiratory Society 7