When you execute a Power of Attorney and designate a fiduciary (Attorney-in-Fact), you are granting an enormous amount of power to that person. Perhaps you have already executed a POA and have named one or more family members to act in your interests financially. They are your family, maybe your children. You should be able to trust them, right?
Will the kids take on the task of protecting your financial well-being and do the right thing? Over time, the dynamics in your family may change. People change. Are the persons you have entrusted to represent what's best for you still the best people for the job?
It might be wise to revisit those legal documents from time to time and ask yourself a tough question--are your fiduciaries are still up to the task? Talking to a qualified estate planning attorney is a good first step to ensuring that your legal instruments still reflect your needs and best interests.