Schiavo case made us actually sit down and execute the necessary documents.
Each state is a little different. The main point is that there should be a declaration setting forth, if you cannot make you position known, the type of care that you want (i.e. full extraordinary means ....no medical devices, but full food and water...no extraordinary means, let me die, etc.) and under what circumstances the directive should be employed (i.e. comatose, incurable disease, etc.). In addition, there should be the appointment of a person to carry out that directive.
Unless this is a well drafted document, the health care providers may have difficulty in following the directive and instruction, and if the matter gets into the Courts, it is very important that the document be State specific and follow the mandates of each State.
The documents shouldn't cost more that $100-150. Get a lawyer who works in the estates area.
uncledrz