Health Care Powers of Attorney and Living Wills are terms that are commonly known, but seem to be constantly misunderstood. Part of an attorneys' job is to educate clients and others regarding how legal documents--such as POAs and Living Wills--work.
A Health Care POA allows a person ("Principal") to appoint another person (the "Agent") to make medical decisions/receive medical information if the Principal is not able to do so himself.
Powers in Healthcare POA include the power to withhold/withdraw certain life-sustaining treatments (specified how to do so in the Living Will portion of the document); the power to hire/fire medical personnel; and the power to admit/discharge Principal to/from hospital or nursing home facilities, among other powers.
Powers in the Healthcare POA do not allow Agents to withhold or withdraw life support/life sustaining treatment if the Principal is not in an end-stage medical condition. Also, they do not allow the Agent to act indefinitely; while Health Care POA is presumed durable (exists past point of Principal's incapacity), the Principal can revoke the POA at any time.
Finally, a Health Care POA does not allow the Agent to admit Principal to nursing home if it is against the Principal's desires. Thus, Agent's powers are not equal to or greater than the Principal's powers. The Principal is always in charge of his or her medical care and treatment.
Since the provisions of a "Living Will" are triggered only in the case of an "End Stage" medical condition, it is important to know what the term means. An "End Stage” medical condition occurs when the Principal is in a permanent state of unconsciousness or an irreversible coma and a physician has certified to a reasonable degree of medical certainty that there is no realistic hope of significan recovery. Thus, you do not have to worry about an Agent removing life support unless doctors are certain that you (the Principal) will not wake up or otherwise recover.
Such a designation [as End-Stage] triggers most of end of life provisions in a Living Will (or other advanced directive), such as withholding or withdrawing aggressive medical care, and withholding or withdrawing tube feedings (such as water and food through a tube).
Decisions regarding end-of-life care are difficult for every family, and even having your wishes in writing is not guarantee that they will be honored by children, who may have difficulty enforcing your wishes. It is better to discuss end-of-life decisions with children (both the Agent and other children) to ensure all children are aware of your desires. This level of communication increases likelihood that decisions will be made in accordance with your wishes.
Finally, consider choosing only one Agent, rather than multiple Co-Agents, to ensure that there is only one decision-maker at a time.