15. a. Consistent with the terms of an advance directive and the provisions of this act, life-sustaining treatment may be withheld or withdrawn from a patient in the following circumstances:
(1) When the life-sustaining treatment is experimental and not a proven therapy, or is likely to be ineffective or futile in prolonging life, or is likely to merely prolong an imminent dying process;
(2) When the patient is permanently unconscious, as determined by the attending physician and confirmed by a second qualified physician;
(3) When the patient is in a terminal condition, as determined by the attending physician and confirmed by a second qualified physician; or
(4) In the event none of the above circumstances applies, when the patient has a serious irreversible illness or condition, and the likely risks and burdens associated with the medical intervention to be withheld or withdrawn may reasonably be judged to outweigh the likely benefits to the patient from such intervention, or imposition of the medical intervention on an unwilling patient would be inhumane. In such cases prior to implementing a decision to withhold or withdraw life-sustaining treatment, the attending physician may promptly seek consultation with an institutional or regional reviewing body in accordance with section 17 of this act, or may promptly seek approval of a public agency recognized by law for this purpose.
b. Nothing in this section shall be construed to impair the obligations of physicians, nurses and other health care professionals to provide for the care and comfort of the patient and to alleviate pain, in accordance with accepted medical and nursing standards.
c. Nothing in this section shall be construed to abridge any constitutionally-protected right to refuse treatment under either the United States Constitution or the Constitution of the State of New Jersey.