SCOPE AND DURATION OF AUTHORITY.

(a) Subject to this subchapter or any express limitation on the authority of the agent contained in the medical power of attorney, the agent may make any health care decision on the principal's behalf that the principal could make if the principal were competent.

(b) An agent may exercise authority only if the principal's attending physician certifies in writing and files the certification in the principal's medical record that, based on the attending physician's reasonable medical judgment, the principal is incompetent.

(c) Notwithstanding any other provisions of this subchapter, treatment may not be given to or withheld from the principal if the principal objects regardless of whether, at the time of the objection:

(1) a medical power of attorney is in effect; or

(2) the principal is competent.

(d) The principal's attending physician shall make reasonable efforts to inform the principal of any proposed treatment or of any proposal to withdraw or withhold treatment before implementing an agent's advance directive.

(e) After consultation with the attending physician and other health care providers, the agent shall make a health care decision:

(1) according to the agent's knowledge of the principal's wishes, including the principal's religious and moral beliefs; or

(2) if the agent does not know the principal's wishes, according to the agent's assessment of the principal's best interests.

(f) Notwithstanding any other provision of this subchapter, an agent may not consent to:

(1) voluntary inpatient mental health services;

(2) convulsive treatment;

(3) psychosurgery;

(4) abortion; or

(5) neglect of the principal through the omission of care primarily intended to provide for the comfort of the principal.

(g) The power of attorney is effective indefinitely on execution as provided by this subchapter and delivery of the document to the agent, unless it is revoked as provided by this subchapter or the principal becomes competent. If the medical power of attorney includes an expiration date and on that date the principal is incompetent, the power of attorney continues to be effective until the principal becomes competent unless it is revoked as provided by this subchapter.