Illness and injury may damage our health to a point that further aggressive therapy is futile or even cruel.

Think about an aged person with dementia who is unresponsive and depends upon a feeding tube for nutrition. A cancer for which there is no therapy may have spread widely and produced unremitting pain. A head injury or stroke may have cast a man or woman into a chronic vegetative state.

Technology can provide a heartbeat, respirations, nutrition and elimination of wastes almost indefinitely. Quality of life is another matter.

In our health-care system we place a high value on personal autonomy - the right to choose, within ethical boundaries, our care-givers and the therapy that they recommend. Nowhere is that autonomy more essential than in selecting how we wish to be treated when there is no prospect for regaining those faculties which we deem essential to our humanness. We want to be able to give and receive affection, to reason, to have a sense of self, to sense and to participate in our environment.

Our desire for autonomy may collide with a medical system that is geared to sustain life by whatever means necessary. Thus life-sustaining technologies will be added even when there is no prospect that a life outside of an intensive care unit can be restored.

These considerations highlight the importance of advance directives. These allow us to select - in a time of good health - how we wish to be treated when we may no longer be capable of making independent decisions.

In Tennessee the relevant documents may be accessed at http://health.state.tn.us/advanced.directives/index.htm.

An "advance care plan" permits the appointment of an agent to manage our decisions if we are unable to do so. The document allows us to select parameters of quality of life and those treatments - such as life-support and tube-feedings - that we desire or decline. A second document authorizes our appointment of a health care agent or surrogate decision-maker to assure that our choices are honored if we are incapable. Two competent witnesses or a notary public must witness the signature of the person completing the document.

The documents vary from state to state. Hence new documents should be completed when we move to another state. The documents should be updated periodically and always reviewed with our closest kin and the person we select as our agent. Copies of the document should be given to a personal physician and the health care agent. A copy must be readily accessible in personal papers or, better yet, carried in an electronic data-stick.

Completion of these documents is not a trivial matter. At issue is our very definition of life and those aspects of our lives that we cherish. Careful discussions with loved ones and a personal care-giver are essential.

The Affordable Care Act of 2011 acknowledged this need by encouraging conversations and providing reimbursement for physicians who undertake such discussions with their patients. This provision was misrepresented as a "death panel" by critics of the ACA.

Only a small minority of senior citizens have completed advance directives. A notable exception is the city of La Crosse, Wisconsin where more than 90 per cent of seniors have enacted such documents. A sustained public information campaign led to this outcome.

Perhaps if we changed the terminology related to directives, we would achieve wider use. We use the unfortunate term "end-of-life" to describe these plans and deliberations. A better term would be planning for "life's farther shore."

Because of the suddenness with which an illness or accident may wreck health adults of every age should consider completing advance directives.

Carefully executed advance directives preserve autonomy, reduce uncertainty, and lessen the emotional burden on our loved ones when we stand on that farther shore.

Contact Clif Cleaveland at cleaveland1000@comcast.net.