Okla. Stat. tit. 59, § 353.1b

A certified registered nurse anesthetist has authority to order, select, obtain and administer drugs pursuant to rules adopted by the Oklahoma Board of Nursing, only when engaged in the preanesthetic preparation or evaluation; anesthesia induction, maintenance or emergence; or postanesthesia care practice of nurse anesthesia. A certified registered nurse anesthetist may order, select, obtain and administer drugs only during the perioperative or periobstetrical period.