Correct, the Living Will or Advanced Directive provides insight into the patient's prior wishes (assuming he/she cannot make decisions about his/her care). The Next of Kin has the responsibility to carry out the wishes stipulated in the Living Will or what the patient's wishes 'would be'.
So, I guess one must chose his/her spouse very well or designate someone to make those decisions.
Where I live, there is no law that says you have to choose a spouse or family member as your designee.
Where I live, there is no law that says you have to choose a spouse or family member as your designee.
A living will is a sure way to guarantee that you will get substandard medical care.
You are indemnifying the hospital/doctor against neglect.