Does anyone know anything about dissolving any kind of legal bond you might have with your parents that is assumed by society?

For example, I am an unmarried almost 30 year old who has not seen or spoken to my abusive parents for over ten years. They are 200 miles from me, but in the same state. I understand that legally they are my next of kin, and would have rights I do not wish them to have should something happen to me. I would like a way to terminate those rights.

Durable power of attorney? Any other ideas?