Center to Advance Palliative Care

In Nevada we have a law that requires written consent to withhold or withdraw life support. Can someone share with me the laws governing this in the state they practice in? I am working with legislation to change this to implied consent
NRS 449.626 Written consent to withhold or withdraw life-sustaining treatment.
1. If written consent to the withholding or withdrawal of the treatment, attested by two witnesses, is given to the attending physician, the attending physician may withhold or withdraw life-sustaining treatment from a patient who:
(a) Has been determined by the attending physician to be in a terminal condition and no longer able to make decisions regarding administration of life-sustaining treatment; and
(b) Has no effective declaration.
2. The authority to consent or to withhold consent under subsection 1 may be exercised by the following persons, in order of priority:
(a) The spouse of the patient;
(b) An adult child of the patient or, if there is more than one adult child, a majority of the adult children who are reasonably available for consultation;
(c) The parents of the patient;
(d) An adult sibling of the patient or, if there is more than one adult sibling, a majority of the adult siblings who are reasonably available for consultation; or
(e) The nearest other adult relative of the patient by blood or adoption who is reasonably available for consultation.
3. If a class entitled to decide whether to consent is not reasonably available for consultation and competent to decide, or declines to decide, the next class is authorized to decide, but an equal division in a class does not authorize the next class to decide.
4. A decision to grant or withhold consent must be made in good faith. A consent is not valid if it conflicts with the expressed intention of the patient.
5. A decision of the attending physician acting in good faith that a consent is valid or invalid is conclusive.
6. Life-sustaining treatment must not be withheld or withdrawn pursuant to this section from a patient known to the attending physician to be pregnant so long as it is probable that the fetus will develop to the point of live birth with continued application of life-sustaining treatment.
(Added to NRS by 1991, 631)