Why give high flow oxygen to type 2 respiratory failure?

High-Flow Nasal Cannula (HFNC) oxygen therapy is commonly used in the management of type 2 respiratory failure, particularly in patients with underlying chronic respiratory conditions such as chronic obstructive pulmonary disease (COPD) or acute exacerbations of asthma. Here are the reasons why high-flow oxygen is beneficial in type 2 respiratory failure:

1. Improved Oxygenation: HFNC delivers a high flow of humidified oxygen directly to the patient's airway through nasal cannulae at flow rates ranging from 30 to 60 liters per minute. This high flow of oxygen helps to wash out carbon dioxide (CO2) from the airway and improve oxygenation. By increasing the partial pressure of oxygen (PaO2) and decreasing the partial pressure of carbon dioxide (PaCO2), HFNC can help correct respiratory acidosis and improve gas exchange.

2. Non-Invasive Ventilation: HFNC provides respiratory support without the need for invasive mechanical ventilation, which can be especially beneficial for patients with type 2 respiratory failure who may be anxious or claustrophobic. HFNC allows patients to maintain spontaneous breathing efforts while receiving controlled oxygen delivery and respiratory support.

3. Reduced Work of Breathing: HFNC can reduce the work of breathing by providing positive airway pressure (PAP). The high flow of oxygen creates mild airway distending pressure, which helps to splint open the airways and reduce the resistance to airflow. This reduced work of breathing can improve respiratory muscle function and decrease the feeling of dyspnea.

4. Improved Mucociliary Clearance: The humidified oxygen delivered through HFNC helps to hydrate the airway secretions, making them thinner and easier to clear. Improved mucociliary clearance facilitates the removal of mucus plugs and secretions from the airways, reducing the risk of respiratory infections and promoting overall lung health.

5. Patient Comfort and Tolerance: HFNC is generally well-tolerated by patients compared to other forms of non-invasive ventilation. The nasal cannula is less intrusive and more comfortable than a face mask or mouthpiece, and it allows patients to talk, eat, and drink without significant interruption.

6. Early Intervention and Prevention: In patients with acute respiratory failure, HFNC can be used as an early intervention to prevent the need for more invasive mechanical ventilation. By providing timely respiratory support and improving gas exchange, HFNC can help stabilize the patient's condition and reduce the risk of complications.

It's important to note that while HFNC can provide significant benefits in type 2 respiratory failure, it should be used under the guidance and monitoring of a healthcare professional. The specific settings and flow rates of HFNC should be adjusted based on the patient's individual needs and response to therapy.