In addition to attorney-prepared health care planning documents like Health Care Powers of Attorney, Living Wills and HIPAA Authorizations, I often talk to clients about Do Not Resuscitate (DNR) Orders and the newer Medical Order Scope of Treatment (MOST) Form. These two forms can be obtained only from one's physician, and must be signed by the physician to be valid.
Laypersons often get Living Wills and DNRs confused, and many physicians are unaware of the MOST form. For those who are elderly or seriously ill, a conversation with one's physician about whether or not to use a DNR or MOST is in order. The North Carolina Medical Society's website contains quite a bit of information and sample forms.