Which gas is commonly mixed with oxygen to improve patient comfort during long-term therapy?

The gas commonly mixed with oxygen to enhance patient comfort during long-term therapy is air. By blending oxygen with a certain amount of air, which is primarily composed of nitrogen and oxygen at a natural atmospheric ratio, the oxygen concentration can be adjusted to ensure that patients feel more comfortable and maintain normal physiological function.

Using air in this context helps to reduce the sensation of oxygen toxicity and can alleviate discomfort associated with delivering high concentrations of oxygen. It allows patients to receive the necessary oxygenation without experiencing side effects that high levels of supplemental oxygen might cause. This method is particularly beneficial in long-term therapy situations where comfort and compliance are essential for treatment success.

Other gases listed tend to serve different purposes or are used in different medical contexts, but air is specifically known for aiding comfort during oxygen therapy.