Here’s another reason (if you need one) to be very, very careful about who you choose as your attorney (for care in this case, but property is relevant too): a woman in Missouri is accused of murdering her father by using a Power of Attorney to withhold treatment and cause his death.
Choosing the proper attorney is very important. This is obviously an extreme case, and there are questions about the validity of the Power of Attorney document, but it highlights the fact that, if you don’t prepare a document yourself, someone could arrange for treatment that you really don’t want.
You can read more about the case here.