What is a medical use for Helium (He)?

Helium (He) has a specific medical application in lung function testing, particularly as a wash-out gas. In pulmonary function tests, helium is utilized due to its low density and ability to easily diffuse through the alveolar membranes. This facilitates the assessment of lung volumes and helps in determining if there is any obstruction or restriction in airflow. When inhaled, helium mixes with the air in the lungs, and by measuring the concentration of helium after a certain period, clinicians can gauge how well the lungs are functioning.

The other options are less applicable to helium. While anesthetic agents typically include gases like nitrous oxide or volatile anesthetics, helium does not serve that purpose. Regarding oxygen delivery, helium does not directly provide oxygen; rather, it can be used to enhance the flow of oxygen, especially in cases of obstructive airway disease. Insufflation during surgery is generally performed using carbon dioxide or air, as these gases are better suited for that application due to their physiological properties and effects on the body.