The Orlando Sentinel has an article about a lawsuit where a hospital and nursing home ignored a do not resuscitate order:
Lawsuit raises issues about end-of-life wishes
I haven’t seen the lawsuit and I don’t know how likely it is that she is going to win; but it does illustrate the point that sometimes, either innocently or deliberately, that a hospital, a nursing home, a physician, or other medical provider will ignore wishes in a living will, a DNR order, or a health care surrogacy. Sometimes, if the medical provider does not have a copy of the paperwork, they clearly are not about to not to try to save someone; sometimes they do have a copy of the paperwork, but for whatever reason, they refuse to accept it or refuse to follow the instructions.
Every case is going to be different; but if this happens to you call a lawyer immediately; depending on the circumstances, a phone call by the lawyer to the medical provider may be enough to get them to recognize the paperwork, or a lawsuit and court order might be required.