Prior to providing, withholding, or withdrawing treatment for which authorization has been obtained or will be sought under this subtitle, the attending physician and a second physician, nurse practitioner, or physician assistant, one of whom shall have examined the patient within 2 hours before making the certification, shall certify in writing that the patient is incapable of making an informed decision regarding the treatment. The certification shall be based on a personal examination of the patient. If a patient is unconscious, or unable to communicate by any means, the certification of a second physician, nurse practitioner, or physician assistant is not required under paragraph (1) of this subsection. When authorization is sought for treatment of a mental illness, the second physician, nurse practitioner, or physician assistant may not be otherwise currently involved in the treatment of the person assessed. The cost of an assessment to certify incapacity under this subsection shall be considered for all purposes a cost of the patient’s treatment. A health care provider may not withhold or withdraw life–sustaining procedures on the basis of an advance directive where no agent has been appointed or on the basis of the authorization of a surrogate, unless: The patient’s attending physician and a second physician, nurse practitioner, or physician assistant have certified that the patient is in a terminal condition or has an end–stage condition; or Two physicians, one of whom is a neurologist, neurosurgeon, or other physician who has special expertise in the evaluation of cognitive functioning, certify that the patient is in a persistent vegetative state.