Not even living wills. It took less than that to put in motion the offing of Terri.
We need Constitutional amendment support to prevent more Terris. Legislation isn't enough in some cases.
We need G*d fearing people in elected office that know the diference between right and wrong and have the courage to stand and fight.
The law, even the constitution, has limits. The remedy lies in the hearts of men. Choose your surrogates with care, and choose surrogates! My advice is to put NOTHING in writing, because the written words can be misconstrued. Trust you surrogate to assert ethical judgement in the face of an unethical legal and medical community. Not all lawyers and doctors are unethical, but it's the "safe bet" to assume they are.