If, despite their age, they are still mentally competent, they can give you authority over their medical decisions by creating what is commonly called a "heath care proxy" or "medical power of attorney." This is voluntary on their part--you cannot make them do this, or otherwise take authority over mentally competent adutls' medical decisions. If they want to do this, an elder law attorney can easily draw the document up.
If you believe they are no longer mentally competent--and believe there is medical evidence (e.g. the testimony and opinions of doctors who have been treating or examining them) supporting their incompetence--you could bring a legal action to have them declared incompetent and a guardian (e.g. you) appointed for them to make medical (and other) decisions. Be warned this can be a complex, expensive action to bring (among other things, you have to find doctors who can testify to their incompetence and pay those doctors for their time). If want to find out more about this option, consult with an elder law attorney or an attorney who handles cases involving the disabled.
Rate This Answer:
The Answer(s) provided above are for general information only. The attorney providing the answer was not serving as the attorney for the person submitting the question or in any attorney-client relationship with such person. Laws may vary from state to state, and sometimes change. Tiny variations in the facts, or a fact not set forth in a question, often can change a legal outcome or an attorney's conclusion. Although AttorneyPages.com has verified the attorney was admitted to practice law in at least one jurisdiction, he or she may not be authorized to practice law in the jurisdiction referred to in the question, nor is he or she necessarily experienced in the area of the law involved. Unlike the information in the Answer(s) above, upon which you should NOT rely, for personal advice you can rely upon we suggest you go to AttorneyPages.com
and retain an attorney to represent you.