Unless there is a durable power of attorney for health care or another writing clearly expressing an individual's intent to the contrary, an agent or surrogate may not consent on behalf of a patient to an abortion, sterilization, psychosurgery, or removal of bodily organs except when the abortion, sterilization, psychosurgery, or removal of bodily organs is necessary to preserve the life of the patient or to prevent serious impairment of the health of the patient.