Which oxygen delivery method requires the highest flow rate?

The non-rebreather mask is designed for providing the highest concentration of oxygen to a patient and thus requires a higher flow rate compared to other delivery methods. This mask features a reservoir bag and one-way valves that prevent the patient's exhaled air from re-entering the bag, allowing for a nearly pure oxygen supply when the patient inhales. The typical flow rate for a non-rebreather mask is usually set between 10 to 15 liters per minute to keep the reservoir bag inflated and to ensure that the patient receives a higher percentage of oxygen, often between 80 to 100%.

In contrast, the other methods of oxygen delivery have different flow rate requirements and efficiencies. A nasal cannula generally operates effectively at lower flow rates, typically around 1 to 6 liters per minute, and is suitable for patients who require less supplemental oxygen. A simple mask requires a moderate flow rate, usually between 6 to 10 liters per minute, to prevent the rebreathing of exhaled carbon dioxide while still delivering a decent level of oxygen. The bag-valve-mask is also used to deliver high concentrations of oxygen, particularly in an emergent situation; however, it relies on manual ventilation and fluctuates based on the effort of the person