Texas Health and Safety Code - HEALTH & SAFETY § 166.156. Appointment of Guardian

(a) On motion filed in connection with a petition for appointment of a guardian or, if a guardian has been appointed, on petition of the guardian, a probate court shall determine whether to suspend or revoke the authority of the agent.

(b) The court shall consider the preferences of the principal as expressed in the medical power of attorney.

(c) During the pendency of the court's determination under Subsection (a), the guardian has the sole authority to make any health care decisions unless the court orders otherwise.  If a guardian has not been appointed, the agent has the authority to make any health care decisions unless the court orders otherwise.

(d) A person, including any attending physician or health or residential care provider, who does not have actual knowledge of the appointment of a guardian or an order of the court granting authority to someone other than the agent to make health care decisions is not subject to criminal or civil liability and has not engaged in unprofessional conduct for implementing an agent's health care decision.