As it stands, all provinces but New Brunswick require consent from the patient or substitute decision-maker for medical treatment, and Ontario is the only one with a tribunal that makes decisions on a patient’s behalf.
Of course, the ideal is for the patient and family and doctor to have talked through such matters in advance , but where that has not occurred, a clear legal standard will come in handy.
In my former hospital, we had a procedure in place for those instances in which a doctor felt that a patient or family was demanding a harmful or ineffective treatment. But as I re-read that policy today, it seems to be focused on the initiation of such treatment. I am not sure whether it should or could apply to the withdrawal of treatment, i.e., the kind of case being considered here by the Canadian court.
I think, too, in the United States, that these would be matters of state, and not national, jurisdiction. Perhaps readers who are more familiar with the various states' laws on these issues will provide us all with the benefit of your comments.