When should we not respect a patient's wish?

Patients who face making a high-stakes decision-whether or not to accept a lifesaving intervention-may make a decision that their careproviders believe is deeply and dangerously mistaken. How can careproviders best help patients in such situations? If a determination of competency exam seems to be in the patients' best interests, how can careproviders refer their patients without betraying their patients' trust, given that the trust between patients and careproviders is one of the most powerful tools careproviders have in working with patients? Ethically, is it possible for careproviders to participate in determinations of competency for their own patients? I will present approaches that careproviders can adopt to help patients who "won't budge" when making what appear to be dangerously erroneous choices regarding lifesaving interventions.