- Welcome to the home page for the Oklahoma Association of Nurse Anesthetists. We are over 240 nurse anesthetists (CRNAs) working in Oklahoma serving both urban and rural health care. CRNAs work with anesthesiologists, physicians such as surgeons, and administer approximately 65% of all anesthetics given each year. CRNAs work in every setting in which anesthesia is delivered: tertiary care ...www.oana.org