The principal may so revoke at any time and in any manner. The revocation shall be effective when the principal expresses an intention to so revoke, except that, if the principal made the principal's attending physician aware of the durable power of attorney for health care, the revocation shall be effective upon its communication to the attending physician by the principal, a witness to the revocation, or other health care personnel to whom the revocation is communicated by such a witness. Absent actual knowledge to the contrary, the attending physician of the principal and other health care personnel who are informed of the revocation of a durable power of attorney for health care by an alleged witness may rely on the information and act in accordance with the revocation.
R.C. §1337.14