An individual is considered dead if, in the opinion of a physician licensed or exempt from licensing under AS 08.64 or a registered nurse authorized to pronounce death under AS 08.68.700, based on acceptable medical standards, or in the opinion of a mobile intensive care paramedic, physician assistant, or emergency medical technician authorized to pronounce death based on the medical standards in AS 18.08.089, the individual has sustained irreversible cessation of circulatory and respiratory functions, or irreversible cessation of all functions of the entire brain, including the brain stem. Death may be pronounced in this circumstance before artificial means of maintaining respiratory and cardiac function are terminated.