The National Hospice and Palliative Care Organization wrote in its 2005 pamphlet, "Questions and Answers: Advance Directive and End-of-Life Decisions":
"A medical power of attorney is a document that lets you appoint someone you trust to make decisions about your medical care if you cannot make them yourself.
This type of advance directive can also be called a 'healthcare proxy,' 'appointment of a healthcare agent,' or 'durable power of attorney for healthcare.' The person you appoint may be called your healthcare agent, surrogate, attorney-in-fact, or healthcare proxy. The person you appoint through a medical power of attorney usually is authorized to deal with all medical situations, not only end-of-life decisions when you cannot speak for yourself. Thus, he or she can speak for you if you become termporarily incapacitated--after an accident, for example--as well as if you become incapacitated because of irreversible disease or injury.
Generally, the law requires your agent to make the same medical decisions that you would have made, if possible. To help your agent do this, it is essential that you discuss your values about the quality of life that is impotant to you and the kinds of decisions you would make in various situations... These discussions will help your agent to form a picture of your views regarding the use of medical treatments...
When your wishes about a particular medical decision are not known your agent must act in your best interest, using his or her own judgment depending on your state's law."
The American Bar Association explained in its website's section on "Law for Older Americans," (accessed on Aug. 3, 2006):
A health care power of attorney (or health care 'proxy,' or 'medical power of attorney') is a document that appoints someone of your choosing to be your authorized 'agent' (or 'attorney-in-fact' or 'proxy'). You can give your agent as much or as little authority as you wish to make health care decisions. The decisions are not limited to just end-of-life decisions. Appointing an agent provides someone with authority to weigh all the medical facts and circumstances and interpret your wishes accordingly. A health care power of attorney is broader and more flexible than the living will."