Notwithstanding any other provision of this chapter, an agent or a surrogate may determine that life-sustaining procedures may be withheld or withdrawn from a patient with a qualifying condition when there is
(1) a durable power of attorney for health care or other writing that clearly expresses the patient's intent that the procedures be withheld or withdrawn; or
(2) no durable power of attorney for health care or other writing that clearly expresses the patient's intent to the contrary, the patient has a qualifying condition as determined under AS 13.52.160, and withholding or withdrawing the procedures would be consistent with the patient's best interest.