What is the primary function of soda lime in a xenon administration unit?

The primary function of soda lime in a xenon administration unit is to absorb carbon dioxide. Soda lime is a chemical mixture of sodium hydroxide and calcium hydroxide, specifically designed to remove carbon dioxide from a closed system, such as the equipment used during xenon inhalation studies. When patients inhale xenon, it is necessary to maintain a suitable concentration of this inhaled agent while preventing the buildup of carbon dioxide produced by their respiratory process. By effectively trapping carbon dioxide, soda lime helps to ensure that the xenon remains effective and that the patient can breathe in a controlled environment.

Other options focus on functions not served by soda lime in this context, such as absorbing moisture or xenon itself, which are not relevant to the usage of soda lime in this specific application.