S.C. Code § 44-77-85
The declarant may indicate in the declaration whether he wants to appoint an agent to act on his behalf in assuring that the declaration is given effect by petitioning the court of common pleas for an order directing providers to withhold or withdraw treatment as provided in the declaration. The authority of a person designated pursuant to this section is not affected by the subsequent appointment of a guardian or by the declarant's execution of a durable power of attorney before or after execution of the declaration. If the agent is not reasonably available, or is unable or unwilling to ensure that the declaration be given effect, an interested person may petition the court of common pleas for an order directing providers to withhold or withdraw treatment as provided in the declaration. Nothing in this section alters the self-executing nature of a declaration or requires that a court order be obtained or other affirmative action be taken to make the declaration valid or to bring about its implementation. This section does not apply to a declaration that has been revoked as provided in Section 44-77-80.
S.C. Code § 44-77-85