Should I designate Power of Attorney?

You should be able to fill a power of attorney paper when you get to the hospital. Where I work, the papers are all the same, and you get to fill in the blanks or check various options. The social workers will help you do it, and it is free. Yes, you should do it. All surgeries come with risk, and you don't want to be in the situation where someone is making decisions for you, that you don't care for.