The practice of respiratory care includes the following: Professional application of techniques, equipment, and procedures involved in the administration of respiratory care such as: (a) Therapeutic and diagnostic gases (excluding general anesthesia), ...
(COMAR 10.32.11.09B(7)(a)).
As long as the oxygen set-up does not involve any sort of clinical assessment, a respiratory therapist does not have to be involved in the delivery or set-up of oxygen.