Which of the following gases is NOT commonly used in healthcare?

Helium is not commonly used in healthcare compared to the other gases listed. While oxygen is essential for patient respiration, nitrous oxide is widely used as an anesthetic and analgesic agent, and carbon dioxide plays a role in medical procedures like insufflation during laparoscopic surgeries and can be used in respiratory therapies.

Helium, although it has specific applications, such as in some respiratory treatments for conditions like asthma or in specialized diagnostic procedures, is not a primary gas utilized in typical medical practices. In general settings, hospitals and healthcare facilities emphasize the use of oxygen, nitrous oxide, and carbon dioxide much more frequently, making these gases integral to various therapeutic and anesthetic protocols.