If the time comes for a decision to be made, the agent can participate in relevant discussions, weighing the pros and cons of treatment decisions based on your previously expressed wishes. The agent can participate even if decision-making capacity is only temporarily affected. The degree of authority (how much or how little) you want this agent to have can be defined in the document. Alternate agents can also be appointed in case the primary agent is unwilling or unable to act. Additionally, you may name individuals who specifically are NOT to participate in decision-making.
If an agent is not appointed, the law in most states provides for other decision-makers by default, usually beginning with the spouse and adult children and ending with the patient’s physician. Physicians tend to err on the side of prolonging life so their decisions may not be consistent with the patient’s desires. In some cases, if the patient does not have an AD, a court may be required to appoint a guardian.