High flow nasal cannula (HFNC) and standard nasal cannula are both methods of delivering oxygen to patients, but they differ in several key aspects:
1. Flow Rate: The most significant difference between high flow nasal cannula and standard nasal cannula is the flow rate of oxygen delivered. Standard nasal cannula typically delivers oxygen at a flow rate of up to 6 liters per minute (LPM), while high flow nasal cannula can deliver significantly higher flow rates, usually ranging from 20 to 60 LPM. The higher flow rate of HFNC allows for better oxygenation and ventilation.
2. Humidification: High flow nasal cannula provides heated and humidified oxygen, which helps to prevent the drying of the airways. In contrast, standard nasal cannula does not provide humidification, which can lead to dryness and discomfort in the nasal passages.
3. Fraction of Inspired Oxygen (FiO2): High flow nasal cannula can deliver a higher fraction of inspired oxygen (FiO2) compared to standard nasal cannula. The FiO2 provided by HFNC can be adjusted to meet the patient’s specific oxygen needs, ranging from 21% (room air) up to 100%. Standard nasal cannula typically delivers a fixed FiO2 of around 24-44%.
4. Positive End-Expiratory Pressure (PEEP) Effect: High flow nasal cannula can provide a positive end-expiratory pressure (PEEP) effect, which helps to keep the airways open during exhalation. This can improve oxygen exchange in the lungs and reduce the work of breathing. Standard nasal cannula does not provide PEEP.
5. Applications: Standard nasal cannula is commonly used for patients who require low to moderate levels of supplemental oxygen, such as those with mild respiratory conditions or during post-operative recovery. High flow nasal cannula is typically reserved for patients who require higher flow rates of oxygen and/or additional respiratory support, such as those with acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD), or congestive heart failure (CHF).
