What is the most common device used to deliver low concentrations and low flow of oxygen?

• A. Nasal cannula
• B. Face mask
• C. Venturi mask
• D. Oxygen therapy bag

Answer: (A)

The nasal cannula is the most common device used to deliver low concentrations and low flow of oxygen because it allows for a comfortable and non-intrusive way to provide supplemental oxygen. It consists of two small prongs that fit into the nostrils, allowing the patient to breathe oxygen while still being able to talk, eat, and drink. This flexibility makes it particularly suitable for patients who require low-flow oxygen, usually in the range of 1 to 6 liters per minute, which corresponds to oxygen concentrations of approximately 24% to 44% depending on the flow rate.

In contrast, a face mask typically delivers higher concentrations of oxygen and might not be ideal for prolonged use as it can be cumbersome and restricts patient movement. A Venturi mask is designed to deliver specific concentrations of oxygen and is generally used when more precise control of oxygen delivery is needed, often for patients with COPD. An oxygen therapy bag, or reservoir bag, is primarily used for delivering higher concentrations of oxygen and requires a higher flow rate, making it less applicable for low-flow situations. Thus, the nasal cannula stands out for its versatility and patient comfort in providing low concentrations of oxygen.