You want Ethics. I got your ethics right here
Here's one I'm facing now:
Patient recently hospitalized and discharged 3 days ago. On recent hospitalization, although patient was medically futile, he expressed his wishes to be full code (to be resuscitated and intubated if necessary). He now returns completely unconcious and the health care proxy wants to make him DNR (Do Not Resuscitate).
The health care proxy does not mention any recent chage of heart that the pateint spoke of. You're the doctor, what do you do now?