(a) In addition to such other persons as may be authorized and empowered, any one of the following persons is authorized and empowered to consent, either orally or otherwise, to any surgical or medical treatment or procedures not prohibited by law which may be suggested, recommended, prescribed, or directed by a duly licensed physician:

(1) Any adult, for himself, whether by living will or otherwise;

(1.1) Any person authorized to give such consent for the adult under a health care agency complying with Chapter 36 of Title 31, the "Durable Power of Attorney for Health Care Act";

(2) In the absence or unavailability of a living spouse, any parent, whether an adult or a minor, for his minor child;

(3) Any married person, whether an adult or a minor, for himself and for his spouse;

(4) Any person temporarily standing in loco parentis, whether formally serving or not, for the minor under his care; and any guardian, for his ward;

(5) Any female, regardless of age or marital status, for herself when given in connection with pregnancy, or the prevention thereof, or childbirth;

(6) Upon the inability of any adult to consent for himself and in the absence of any person to consent under paragraphs (2) through (5) of this subsection, the following persons in the following order of priority:

(A) Any adult child for his parents;

(B) Any parent for his adult child;

(C) Any adult for his brother or sister; or

(D) Any grandparent for his grandchild.

(b) Any person authorized and empowered to consent under subsection (a) of this Code section shall, after being informed of the provisions of this Code section, act in good faith to consent to surgical or medical treatment or procedures which the patient would have wanted had the patient understood the circumstances under which such treatment or procedures are provided.

(c) For purposes of this Code section, "inability of any adult to consent for himself" shall mean a determination in the medical record by a licensed physician after the physician has personally examined the adult that the adult "lacks sufficient understanding or capacity to make significant responsible decisions" regarding his medical treatment or the ability to communicate by any means such decisions.