Which medical gas is primarily used to treat hypoxemia?

Oxygen is primarily used to treat hypoxemia, which is a condition characterized by insufficient oxygen levels in the blood. When patients experience hypoxemia, their tissues and organs may not receive adequate oxygen, leading to various health complications. Supplementing oxygen helps to increase blood oxygen saturation levels, thereby improving cellular respiration and overall body function. Administering oxygen can be essential in various clinical settings, including in patients with respiratory disorders, chronic obstructive pulmonary disease (COPD), or acute conditions that impair oxygen absorption.

The other gases listed do not serve this primary function. Nitrous oxide is mainly used for its anesthetic and analgesic properties, carbon dioxide is typically not administered for oxygenation purposes and is more associated with respiratory function and metabolic processes, and argon is an inert gas with minimal physiological effects concerning oxygen delivery and treatment of hypoxemia.