(a) A person is dead when, according to ordinary standards of medical practice, there is irreversible cessation of the person's spontaneous respiratory and circulatory functions.
(b) If artificial means of support preclude a determination that a person's spontaneous respiratory and circulatory functions have ceased, the person is dead when, in the announced opinion of a physician, according to ordinary standards of medical practice, there is irreversible cessation of all spontaneous brain function. Death occurs when the relevant functions cease.
(c) Death must be pronounced before artificial means of supporting a person's respiratory and circulatory functions are terminated.
(d) A registered nurse, including an advanced practice registered nurse, or physician assistant may determine and pronounce a person dead in situations other than those described by Subsection (b) if permitted by written policies of a licensed health care facility, institution, or entity providing services to that person. Those policies must include physician assistants who are credentialed or otherwise permitted to practice at the facility, institution, or entity. If the facility, institution, or entity has an organized nursing staff and an organized medical staff or medical consultant, the nursing staff and medical staff or consultant shall jointly develop and approve those policies. The executive commissioner of the Health and Human Services Commission shall adopt rules to govern policies for facilities, institutions, or entities that do not have organized nursing staffs and organized medical staffs or medical consultants.